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Description. The northern bobwhite is a moderately-sized quail, and is the only small galliform native to eastern North America. The bobwhite can range from in length with a wingspan. As indicated by body mass, weights increase in birds found further north, as corresponds to Bergmann's rule. In Mexico, northern bobwhites weigh from whereas in the north they average and large males can attain as much as . Among standard measurements, the wing chord is , the tail is the culmen is and the tarsus is . It has the typical chunky, rounded shape of a quail. The bill is short, curved and brown-black in color. This species is sexually dimorphic. Males have a white throat and brow stripe bordered by black. The overall rufous plumage has gray mottling on the wings, white scalloped stripes on the flanks, and black scallops on the whitish underparts. The tail is gray. The clear whistle "bob-WHITE" or "bob-bob-WHITE" call is very recognizable. The syllables are slow and widely spaced, rising in pitch a full octave from beginning to end. Other calls include lisps, peeps, and more rapidly whistled warning calls.
Distribution and habitat. The northern bobwhite can be found year-round in agricultural fields, grassland, open woodland areas, roadsides and wood edges. Its range covers the southeastern quadrant of the United States from the Great Lakes and southern Minnesota east to New York State and southern Massachusetts, and extending west to southern Nebraska, Kansas, Oklahoma, Colorado front-range foothills to 7,000 feet, and all but westernmost Texas. It is absent from the southern tip of Florida (where the extinct Key West bobwhite subspecies once lived) and the highest elevations of the Appalachian Mountains, but occurs in eastern Mexico and in Cuba, and has been introduced to Hispaniola (both the Dominican Republic and Haiti), the Bahamas, the Turks and Caicos Islands, the U.S. Virgin Islands (formerly), Puerto Rico, France, China, Portugal, and Italy. Isolated populations also have been introduced in Oregon and Washington. The northern bobwhite has also been introduced to New Zealand. There is no self-sustaining population in Pennsylvania, where the bird is considered extirpated; it is also considered extirpated in the states of New Hampshire and Connecticut. Its distribution in New York has been limited to Suffolk and Nassau Counties on Long Island, as well as potential population pockets in Upstate New York. The bird is considered declining or extirpated throughout much of the Northeastern United States. Similarly, the bird is almost extirpated from Ontario (and Canada as a whole), with the only self-sustaining population confirmed to exist recorded on Walpole Island.
Behavior and ecology. Like most game birds, the northern bobwhite is shy and elusive. When threatened, it will crouch and freeze, relying on camouflage to stay undetected, but will flush into low flight if closely disturbed. It is generally solitary or paired early in the year, but family groups are common in the late summer and winter roosts may have two dozen or more birds in a single covey. Breeding. The species was once considered monogamous, but with the advent of radio telemetry, the sexual behavior of bobwhites has better been described as ambisexual polygamy. Either parent may incubate a clutch for 23 days, and the precocial young leave the nest shortly after hatching. The main source of nest failure is predation, with nest success averaging 28% across their range. However, the nest success of stable populations is typically much higher than this average, and the aforementioned estimate includes values for declining populations. Brooding behavior varies in that amalgamation (kidnapping, adopting, creching, gang brooding) may occur. An incubating parent may alternatively stay with its young. A hen may re-nest up to four times until she has a successful nest. However, it is extremely rare for bobwhites to hatch more than two successful nests within one nesting season.
Food and feeding. The northern bobwhite's diet consists of plant material and small invertebrates, such as snails, ticks, grasshoppers, beetles, spiders, crickets, and leafhoppers. Plant sources include seeds, wild berries, partridge peas, and cultivated grains. It forages on the ground in open areas with some spots of taller vegetation. Optimal nutrient requirements for bobwhite vary depending on the age of bird and the time of the year. For example, the optimal protein requirement for egg laying hens (23% protein) is much higher than for males (16%). Relationship to humans. Introduced populations. European Union. Northern bobwhite were introduced into Italy in 1927, and are reported in the plains and hills in the northwest of the country. Other reports from the EU are in France, Spain, and the Balkans. As bobwhites are highly productive and popular aviary subjects, it is reasonable to expect other introductions have been made in other parts of the EU, especially in the U.K. and Ireland, where game-bird breeding, liberation, and naturalization are relatively common practices.
New Zealand. From 1898 to 1902, some 1,300 birds were imported from America and released in many parts of the North and South Islands, from Northland to Southland. The bird was briefly on the Nelson game shooting licence, but: "It would seem that the committee was a little too eager in placing these Quail on the licence, or the shooters of the day were over-zealous and greedy in their bag limits, for the Virginian Quail, like the Mountain Quail were soon a thing of the past." The Taranaki (Acclimatisation) Society released a few in 1900 and was confidant that in a year or two they might offer good sport; two years later, broods were reported and the species was said to be "steadily increasing"; but after another two years they seemed "to have disappeared" and that was the end of them. The Otago (Acclimatisation) Society imported more in 1948, but these releases did no good. After 1923, no more genuinely wild birds were sighted until 1952, when a small population was found northwest of Wairoa in the Ruapapa Road area. Since then, bobwhite have been found at several localities around Waikaremoana, in farmland, open bush and along roadsides.
More birds have been imported into New Zealand by private individuals since the 1990s and a healthy captive population is now held by backyard aviculturists and have been found to be easily cared for and bred and are popular for their song and good looks. A larger proportion of the national captive population belong to a few game preserves and game bird breeders. Though the birds would be self-sustaining in the wild if they were protected; it is tricky to guess what the effect of an annual population subsidy and hunting has on any of the original populations from the Acclimatisation Society releases. An albino hen was present in a covey in Bayview, Hawkes Bay for a couple of seasons sometime around 2000. Captivity. Housing. Bobwhites are generally compatible with most parrots, softbills and doves. This species should, however, be the only ground-dwelling species in the aviary. Most individuals will do little damage to finches, but one should watch that nests are not being crushed when the species perches at night. Single pairs are preferred, unless the birds have been raised together as a group since they were chicks. Some fighting will occur between cocks at breeding time. One cock may be capable of breeding with several hens, but the fertility seems to be highest in the eggs from the "preferred" hen. Aviary style is a compromise between what is tolerated by the bird and what is best for the bird. Open parrot-style type aviaries may be used, but some birds will remain flighty and shy in this situation. In a planted aviary, this species will generally settle down to become quite tame and confiding. Parents with chicks will roost on the ground, forming a circular arrangement, with heads facing outwards. In the early morning and late afternoon, the cock will utter his call, which, although not loud, carries well and may offend noise-sensitive neighbors. Most breeding facilities keep birds in breeding groups on wire up off the ground.
Feeding. In the wild the northern bobwhite feeds on a variety of weed and grass seeds, as well as insects. These are generally collected on the ground or from low foliage. Birds in the aviary are easily catered for with a commercial small seed mix (finch, budgerigar, or small parrot mix) when supplemented with greenfeed. Live food is not usually necessary for breeding, but will be ravenously accepted. High protein foods such as chicken grower crumble are more convenient to supply and will be useful for the stimulation of breeding birds. Extra calcium is required, especially by laying hens; it can be supplied in the form of shell grit, or cuttlefish bone. Breeding. If a nesting site and privacy are not provided, hens will lay anywhere within an open aviary. Hens that do this may, in a season, lay upwards of 80 eggs, which can be taken for artificial incubation and the chicks hand-raised. Hens with nesting cover that do make a nest (on the ground) will build up 8–25 eggs in a clutch, with eggs being laid daily.
Mutations and hybrids. Some captive bobwhite hybrids recorded are between blue quail (scaled quail), Gambel's quail, California quail, and mountain quail. It has long been suggested that there are Japanese quail hybrids being bred commercially; however, there is a distinct lack of photographic proof to substantiate this. Inter-subspecific hybrids have been common. Several mutations have long been established, including Californian Jumbo, Wisconsin Jumbo, Northern Giant, Albino, Snowflake, Blonde, Fawn, Barred, Silver, and Red. Status. The northern bobwhite is rated as a Near-threatened species by the International Union for Conservation of Nature. The northern bobwhite is threatened across its range due to habitat loss and habitat degradation. Changing land use patterns and changing fire regimes have caused once prime habitat to become unfavorable for the bobwhite. Masked bobwhite. The masked bobwhite subspecies, "C. v. ridgwayi", is listed as endangered in the U.S. The birds were twice declared extirpated in Arizona in the past century. It was originally endemic to southern Arizona in the U.S., and northern Sonora in Mexico. It is considered a "Critically Imperiled Subspecies" by NatureServe.
The masked bobwhite was in decline since its discovery in 1884. By 1900, the subspecies was already extinct in the U.S. Populations remained in Mexico, but their study was curtailed by political events in Mexico, including the Mexican Revolution and the last of the Yaqui Wars. A population of the masked bobwhite was finally discovered and studied in Mexico, in 1931 and 1932. A native population historically existed in Sonora, but by 2017, its population appeared to be declining, or possibly extinct. A 2017 study recorded no wild sightings of the bird in Sonora. Decline of the species has been attributed to intense livestock grazing in an ecosystem that does not rejuvenate quickly. A captive flock was established in Arizona in the 1970s. The George Miksch Sutton Avian Research Center (Sutton Center) became involved with conservation efforts in 2017 to establish a breeding population at the Sutton Center in Oklahoma, in order to reintroduce birds to Buenos Aires National Wildlife Refuge (BANWR). In 2019, biologists from the Sutton Center transported 1,000 chicks by road vehicle to Buenos Aires National Wildlife Refuge. In 2020, a projected total of 1,200 birds will be transported by airplanes to BANWR. These recent actions are supplemental, and in addition to other conservation efforts in the past, seem to aid the subspecies' future conservation efforts.
In popular culture. In "Eek! The Cat" episode "PolitEekly Correct", while Sharky is chasing Eek, they cause a quail named Bob White to lose his signature call. They travel across the United States and eventually recover his distinctive "bobwhite" call. In 2023, the masked bobwhite subspecies will be featured on a United States Postal Service Forever stamp as part of the "Endangered Species" set, based on a photograph from Joel Sartore's "Photo Ark". The stamp will be dedicated at a ceremony at the National Grasslands Visitor Center in Wall, South Dakota.
Bipolar disorder Bipolar disorder (BD), previously known as manic depression, is a mental disorder characterized by periods of depression and periods of abnormally elevated mood that each last from days to weeks, and in some cases months. If the elevated mood is severe or associated with psychosis, it is called "mania"; if it is less severe and does not significantly affect functioning, it is called "hypomania". During mania, an individual behaves or feels abnormally energetic, happy, or irritable, and they often make impulsive decisions with little regard for the consequences. There is usually, but not always, a reduced need for sleep during manic phases. During periods of depression, the individual may experience crying, have a negative outlook on life, and demonstrate poor eye contact with others. The risk of suicide is high. Over a period of 20 years, 6% of those with bipolar disorder died by suicide, with about one-third attempting suicide in their lifetime. Among those with the disorder, 40–50% overall and 78% of adolescents engaged in self-harm. Other mental health issues, such as anxiety disorders and substance use disorders, are commonly associated with bipolar disorder. The global prevalence of bipolar disorder is estimated to be between 1–5% of the world's population.
While the causes of this mood disorder are not clearly understood, both genetic and environmental factors are thought to play a role. Genetic factors may account for up to 70–90% of the risk of developing bipolar disorder. Many genes, each with small effects, may contribute to the development of the disorder. Environmental risk factors include a history of childhood abuse and long-term stress. The condition is classified as bipolar I disorder if there has been at least one manic episode, with or without depressive episodes, and as bipolar II disorder if there has been at least one hypomanic episode (but no full manic episodes) and one major depressive episode. It is classified as cyclothymia if there are hypomanic episodes with periods of depression that do not meet the criteria for major depressive episodes. If these symptoms are due to drugs or medical problems, they are not diagnosed as bipolar disorder. Other conditions that have overlapping symptoms with bipolar disorder include attention deficit hyperactivity disorder, personality disorders, schizophrenia, and substance use disorder as well as many other medical conditions. Medical testing is not required for a diagnosis, though blood tests or medical imaging can rule out other problems.
Mood stabilizers, particularly lithium, and certain anticonvulsants, such as lamotrigine and valproate, as well as atypical antipsychotics, including quetiapine, olanzapine, and aripiprazole are the mainstay of long-term pharmacologic relapse prevention. Antipsychotics are additionally given during acute manic episodes as well as in cases where mood stabilizers are poorly tolerated or ineffective. In patients where compliance is of concern, long-acting injectable formulations are available. There is some evidence that psychotherapy improves the course of this disorder. The use of antidepressants in depressive episodes is controversial: they can be effective but certain classes of antidepressants increase the risk of mania. The treatment of depressive episodes, therefore, is often difficult. Electroconvulsive therapy (ECT) is effective in acute manic and depressive episodes, especially with psychosis or catatonia. Admission to a psychiatric hospital may be required if a person is a risk to themselves or others; involuntary treatment is sometimes necessary if the affected person refuses treatment.
Bipolar disorder occurs in approximately 2% of the global population. In the United States, about 3% are estimated to be affected at some point in their life; rates appear to be similar in females and males. Symptoms most commonly begin between the ages of 20 and 25 years old; an earlier onset in life is associated with a worse prognosis. Interest in functioning in the assessment of patients with bipolar disorder is growing, with an emphasis on specific domains such as work, education, social life, family, and cognition. Around one-quarter to one-third of people with bipolar disorder have financial, social or work-related problems due to the illness. Bipolar disorder is among the top 20 causes of disability worldwide and leads to substantial costs for society. Due to lifestyle choices and the side effects of medications, the risk of death from natural causes such as coronary heart disease in people with bipolar disorder is twice that of the general population. Signs and symptoms. Late adolescence and early adulthood are peak years for the onset of bipolar disorder. The condition is characterized by intermittent episodes of mania, commonly (but not in every patient) alternating with bouts of depression, with an absence of symptoms in between. During these episodes, people with bipolar disorder exhibit disruptions in normal mood, psychomotor activity (the level of physical activity that is influenced by mood)—e.g. constant fidgeting during mania or slowed movements during depression—circadian rhythm and cognition. Mania can present with varying levels of mood disturbance, ranging from euphoria, which is associated with "classic mania", to dysphoria and irritability. Psychotic symptoms such as delusions or hallucinations may occur in both manic and depressive episodes; their content and nature are consistent with the person's prevailing mood. In some people with bipolar disorder, depressive symptoms predominate, and the episodes of mania are always the more subdued hypomania type.
According to the DSM-5 criteria, mania is distinguished from hypomania by the duration: hypomania is present if elevated mood symptoms persist for at least four consecutive days, while mania is present if such symptoms persist for more than a week. Unlike mania, hypomania is not always associated with impaired functioning. The biological mechanisms responsible for switching from a manic or hypomanic episode to a depressive episode, or vice versa, remain poorly understood. Manic episodes. Also known as a manic episode, mania is a distinct period of at least one week of elevated or irritable mood, which can range from euphoria to delirium. The core symptom of mania involves an increase in energy of psychomotor activity. Mania can also present with increased self-esteem or grandiosity, racing thoughts, pressured speech that is difficult to interrupt, decreased need for sleep, disinhibited social behavior, increased goal-oriented activities and impaired judgement, which can lead to exhibition of behaviors characterized as impulsive or high-risk, such as hypersexuality or excessive spending. To fit the definition of a manic episode, these behaviors must impair the individual's ability to socialize or work. If untreated, a manic episode usually lasts three to six months.
In severe manic episodes, a person can experience psychotic symptoms, where thought content is affected along with mood. They may feel unstoppable, persecuted, or as if they have a special relationship with God, a great mission to accomplish, or other grandiose or delusional ideas. This may lead to violent behavior and, sometimes, hospitalization in an inpatient psychiatric hospital. The severity of manic symptoms can be measured by rating scales such as the Young Mania Rating Scale, though questions remain about the reliability of these scales. The onset of a manic or depressive episode is often foreshadowed by sleep disturbance. Manic individuals often have a history of substance use disorder developed over years as a form of "self-medication". Hypomanic episodes. Hypomania is the milder form of mania, defined as at least four days of the same criteria as mania, but which does not cause a significant decrease in the individual's ability to socialize or work, lacks psychotic features such as delusions or hallucinations, and does not require psychiatric hospitalization. Overall functioning may actually increase during episodes of hypomania and is thought to serve as a defense mechanism against depression by some. Hypomanic episodes rarely progress to full-blown manic episodes. Some people who experience hypomania show increased creativity, while others are irritable or demonstrate poor judgment.
Hypomania may feel good to some individuals who experience it, though most people who experience hypomania state that the stress of the experience is very painful. People with bipolar disorder who experience hypomania tend to forget the effects of their actions on those around them. Even when family and friends recognize mood swings, the individual will often deny that anything is wrong. If not accompanied by depressive episodes, hypomanic episodes are often not deemed problematic unless the mood changes are uncontrollable or volatile. In individuals with Bipolar II disorder, depressive symptoms typically overlap with hypomania symptoms. These individuals may not be able to identify these specific symptoms as hypomania, rather they view them as typical depression with slight alterations in mood. Most commonly, symptoms continue for time periods from a few weeks to a few months. Depressive episodes. Symptoms of the depressive phase of bipolar disorder include persistent feelings of sadness, irritability or anger, loss of interest in previously enjoyed activities, excessive or inappropriate guilt, hopelessness, sleeping too much or not enough, changes in appetite or weight, fatigue, problems concentrating, self-loathing or feelings of worthlessness, and thoughts of death or suicide. Although the DSM-5 criteria for diagnosing unipolar and bipolar episodes are the same, some clinical features are more common in the latter, including increased sleep, sudden onset and resolution of symptoms, significant weight gain or loss, and severe episodes after childbirth.
The earlier the age of onset, the more likely the first few episodes are to be depressive. For most people with bipolar types 1 and 2, the depressive episodes are much longer than the manic or hypomanic episodes. Since a diagnosis of bipolar disorder requires a manic or hypomanic episode, many affected individuals are initially misdiagnosed as having major depression and treated with prescribed antidepressants. Mixed affective episodes. In bipolar disorder, a mixed state is an episode during which symptoms of both mania and depression occur simultaneously. Individuals experiencing a mixed state may have manic symptoms such as grandiose thoughts while simultaneously experiencing depressive symptoms such as excessive guilt or feeling suicidal. They are considered to have a higher risk for suicidal behavior as depressive emotions such as hopelessness are often paired with mood swings or difficulties with impulse control. Anxiety disorders occur more frequently as a comorbidity in mixed bipolar episodes than in non-mixed bipolar depression or mania. Substance (including alcohol) use also follows this trend, thereby appearing to depict bipolar symptoms as no more than a consequence of substance use.
Comorbid conditions. People with bipolar disorder often have other co-existing psychiatric conditions such as anxiety (present in about 71% of people with bipolar disorder), substance abuse (56%), personality disorders (36%) and attention deficit hyperactivity disorder (10–20%) which can add to the burden of illness and worsen the prognosis. Certain medical conditions are also more common in people with bipolar disorder as compared to the general population. This includes increased rates of metabolic syndrome (present in 37% of people with bipolar disorder), migraine headaches (35%), obesity (21%) and type 2 diabetes (14%). This contributes to a risk of death that is two times higher in those with bipolar disorder as compared to the general population. Hypothyroidism is also common regardless of drug choice. Substance use disorder is a common comorbidity in bipolar disorder; the subject has been widely reviewed. Causes. The causes of bipolar disorder likely vary between individuals and the exact mechanism underlying the disorder remains unclear. Genetic influences are believed to account for 73–93% of the risk of developing the disorder indicating a strong hereditary component. The overall heritability of the bipolar spectrum has been estimated at 0.71. Twin studies have been limited by relatively small sample sizes but have indicated a substantial genetic contribution, as well as environmental influence. For bipolar I disorder, the rate at which identical twins (same genes) will both have bipolar I disorder (concordance) is around 40%, compared to about 5% in fraternal twins. A combination of bipolar I, II, and cyclothymia similarly produced rates of 42% and 11% (identical and fraternal twins, respectively). The rates of bipolar II combinations without bipolar I are lowerbipolar II at 23 and 17%, and bipolar II combining with cyclothymia at 33 and 14%which may reflect relatively higher genetic heterogeneity.
The cause of bipolar disorders overlaps with major depressive disorder. When defining concordance as the co-twins having either bipolar disorder or major depression, then the concordance rate rises to 67% in identical twins and 19% in fraternal twins. The relatively low concordance between fraternal twins brought up together suggests that shared family environmental effects are limited, although the ability to detect them has been limited by small sample sizes. Genetic. Behavioral genetic studies have suggested that many chromosomal regions and candidate genes are related to bipolar disorder susceptibility with each gene exerting a mild to moderate effect. The risk of bipolar disorder is nearly ten-fold higher in first-degree relatives of those with bipolar disorder than in the general population; similarly, the risk of major depressive disorder is three times higher in relatives of those with bipolar disorder than in the general population. Although the first genetic linkage finding for mania was in 1969, linkage studies have been inconsistent. Findings point strongly to heterogeneity, with different genes implicated in different families. Robust and replicable genome-wide significant associations showed several common single-nucleotide polymorphisms (SNPs) are associated with bipolar disorder, including variants within the genes "CACNA1C", "ODZ4", and "NCAN". The largest and most recent genome-wide association study failed to find any locus that exerts a large effect, reinforcing the idea that no single gene is responsible for bipolar disorder in most cases. Polymorphisms in "BDNF", "DRD4", "DAO", and "TPH1" have been frequently associated with bipolar disorder and were initially associated in a meta-analysis, but this association disappeared after correction for multiple testing. On the other hand, two polymorphisms in "TPH2" were identified as being associated with bipolar disorder.
Due to the inconsistent findings in a genome-wide association study, multiple studies have undertaken the approach of analyzing SNPs in biological pathways. Signaling pathways traditionally associated with bipolar disorder that have been supported by these studies include corticotropin-releasing hormone signaling, cardiac β-adrenergic signaling, phospholipase C signaling, glutamate receptor signaling, cardiac hypertrophy signaling, Wnt signaling, Notch signaling, and endothelin 1 signaling. Of the 16 genes identified in these pathways, three were found to be dysregulated in the dorsolateral prefrontal cortex portion of the brain in post-mortem studies: "CACNA1C", "GNG2", and "ITPR2". Bipolar disorder is associated with reduced expression of specific DNA repair enzymes and increased levels of oxidative DNA damages. The AKAP11 gene was recently discovered as the first gene linked to bipolar disorder. The exomes of around 14,000 individuals with bipolar disorder were analysed and compared to those without the condition. The findings were combined with data from another study in the Schizophrenia Exome Sequencing Meta-Analysis (SCHEMA), examining the genome sequences of 24,000 people alongside the original 14,000 bipolar disorder cases. This study identified genetic variants, including the AKAP11 gene, associated with an increased risk of bipolar disorder. The AKAP11 gene’s interaction with the GSK3B protein, a molecular target of lithium, points to a possible mechanism behind the medication’s therapeutic effects.
Environmental. Psychosocial factors play a significant role in the development and course of bipolar disorder, and individual psychosocial variables may interact with genetic dispositions. Recent life events and interpersonal relationships likely contribute to the onset and recurrence of bipolar mood episodes, just as they do for unipolar depression. In surveys, 30–50% of adults diagnosed with bipolar disorder report traumatic/abusive experiences in childhood, which is associated with earlier onset, a higher rate of suicide attempts, and more co-occurring disorders such as post-traumatic stress disorder. Subtypes of abuse, such as sexual and emotional abuse, also contribute to violent behaviors seen in patients with bipolar disorder. The number of reported stressful events in childhood is higher in those with an adult diagnosis of bipolar spectrum disorder than in those without, particularly events stemming from a harsh environment rather than from the child's own behavior. Acutely, mania can be induced by sleep deprivation in around 30% of people with bipolar disorder.
Neurological. Less commonly, bipolar disorder or a bipolar-like disorder may occur as a result of or in association with a neurological condition or injury including stroke, traumatic brain injury, HIV infection, multiple sclerosis, porphyria, and rarely temporal lobe epilepsy. Proposed mechanisms. The precise mechanisms that cause bipolar disorder are not well understood. Bipolar disorder is thought to be associated with abnormalities in the structure and function of certain brain areas responsible for cognitive tasks and the processing of emotions. A neurologic model for bipolar disorder proposes that the emotional circuitry of the brain can be divided into two main parts. The ventral system (regulates emotional perception) includes brain structures such as the amygdala, insula, ventral striatum, ventral anterior cingulate cortex, and the prefrontal cortex. The dorsal system (responsible for emotional regulation) includes the hippocampus, dorsal anterior cingulate cortex, and other parts of the prefrontal cortex. The model hypothesizes that bipolar disorder may occur when the ventral system is overactivated and the dorsal system is underactivated. Other models suggest the ability to regulate emotions is disrupted in people with bipolar disorder and that dysfunction of the ventricular prefrontal cortex is crucial to this disruption.
Meta-analyses of structural MRI studies have shown that certain brain regions (e.g., the left rostral anterior cingulate cortex, fronto-insular cortex, ventral prefrontal cortex, and claustrum) are smaller in people with bipolar disorder, whereas other regions are larger (lateral ventricles, globus pallidus, subgenual anterior cingulate, and the amygdala). Additionally, these meta-analyses found that people with bipolar disorder have higher rates of deep white matter hyperintensities. Functional MRI findings suggest that the ventricular prefrontal cortex regulates the limbic system, especially the amygdala. In people with bipolar disorder, decreased ventricular prefrontal cortex activity allows for the dysregulated activity of the amygdala, which likely contributes to labile mood and poor emotional regulation. Consistent with this, pharmacological treatment of mania returns ventricular prefrontal cortex activity to the levels in non-manic people, suggesting that ventricular prefrontal cortex activity is an indicator of mood state. However, while pharmacological treatment of mania reduces amygdala hyperactivity, it remains more active than the amygdala of those without bipolar disorder, suggesting amygdala activity may be a marker of the disorder rather than the current mood state. Manic and depressive episodes tend to be characterized by dysfunction in different regions of the ventricular prefrontal cortex. Manic episodes appear to be associated with decreased activation of the right ventricular prefrontal cortex whereas depressive episodes are associated with decreased activation of the left ventricular prefrontal cortex. These disruptions often occur during development linked with synaptic pruning dysfunction.
People with bipolar disorder who are in a euthymic mood state show decreased activity in the lingual gyrus compared to people without bipolar disorder. In contrast, they demonstrate decreased activity in the inferior frontal cortex during manic episodes compared to people without the disorder. Similar studies examining the differences in brain activity between people with bipolar disorder and those without did not find a consistent area in the brain that was more or less active when comparing these two groups. People with bipolar have increased activation of left hemisphere ventral limbic areaswhich mediate emotional experiences and generation of emotional responsesand decreased activation of right hemisphere cortical structures related to cognitionstructures associated with the regulation of emotions. However, further research is needed to consolidate neuroimaging findings, which are often heterogeneous and not consistently reported according to a common standard. Neuroscientists have proposed additional models to try to explain the cause of bipolar disorder. One proposed model for bipolar disorder suggests that hypersensitivity of reward circuits consisting of frontostriatal circuits causes mania, and decreased sensitivity of these circuits causes depression. According to the "kindling" hypothesis, when people who are genetically predisposed toward bipolar disorder experience stressful events, the stress threshold at which mood changes occur becomes progressively lower, until the episodes eventually start (and recur) spontaneously. There is evidence supporting an association between early-life stress and dysfunction of the hypothalamic-pituitary-adrenal axis leading to its overactivation, which may play a role in the pathogenesis of bipolar disorder. Other brain components that have been proposed to play a role in bipolar disorder are the mitochondria and a sodium ATPase pump. Circadian rhythms and regulation of the hormone melatonin also seem to be altered.
Dopamine, a neurotransmitter responsible for mood cycling, has increased transmission during the manic phase. The dopamine hypothesis states that the increase in dopamine results in secondary homeostatic downregulation of key system elements and receptors such as lower sensitivity of dopaminergic receptors. This results in decreased dopamine transmission characteristic of the depressive phase. The depressive phase ends with homeostatic upregulation potentially restarting the cycle over again. Glutamate is significantly increased within the left dorsolateral prefrontal cortex during the manic phase of bipolar disorder, and returns to normal levels once the phase is over. Medications used to treat bipolar may exert their effect by modulating intracellular signaling, such as through depleting myo-inositol levels, inhibition of cAMP signaling, and through altering subunits of the dopamine-associated G-protein. Consistent with this, elevated levels of Gαi, Gαs, and Gαq/11 have been reported in brain and blood samples, along with increased protein kinase A (PKA) expression and sensitivity; typically, PKA activates as part of the intracellular signalling cascade downstream from the detachment of Gαs subunit from the G protein complex.
Decreased levels of 5-hydroxyindoleacetic acid, a byproduct of serotonin, are present in the cerebrospinal fluid of persons with bipolar disorder during both the depressed and manic phases. Increased dopaminergic activity has been hypothesized in manic states due to the ability of dopamine agonists to stimulate mania in people with bipolar disorder. Decreased sensitivity of regulatory α2 adrenergic receptors as well as increased cell counts in the locus coeruleus indicated increased noradrenergic activity in manic people. Low plasma GABA levels on both sides of the mood spectrum have been found. One review found no difference in monoamine levels, but found abnormal norepinephrine turnover in people with bipolar disorder. Tyrosine depletion was found to reduce the effects of methamphetamine in people with bipolar disorder as well as symptoms of mania, implicating dopamine in mania. VMAT2 binding was found to be increased in one study of people with bipolar mania. Diagnosis. Bipolar disorder is commonly diagnosed during adolescence or early adulthood, but onset can occur throughout life. Its diagnosis is based on the self-reported experiences of the individual, abnormal behavior reported by family members, friends or co-workers, observable signs of illness as assessed by a clinician, and ideally a medical work-up to rule out other causes. Caregiver-scored rating scales, specifically from the mother, have shown to be more accurate than teacher and youth-scored reports in identifying youths with bipolar disorder. Assessment is usually done on an outpatient basis; admission to an inpatient facility is considered if there is a risk to oneself or others.
The most widely used criteria for diagnosing bipolar disorder are from the American Psychiatric Association's (APA) "Diagnostic and Statistical Manual of Mental Disorders", Fifth Edition (DSM-5) and the World Health Organization's (WHO) "International Statistical Classification of Diseases and Related Health Problems", 10th Edition (ICD-10). The ICD-10 criteria are used more often in clinical settings outside of the U.S. while the DSM criteria are used within the U.S. and are the prevailing criteria used internationally in research studies. The DSM-5, published in 2013, includes further and more accurate specifiers compared to its predecessor, the DSM-IV-TR. This work has influenced the eleventh revision of the ICD, which includes the various diagnoses within the bipolar spectrum of the DSM-V. Several rating scales for the screening and evaluation of bipolar disorder exist, including the Bipolar spectrum diagnostic scale, Mood Disorder Questionnaire, the General Behavior Inventory and the Hypomania Checklist. The use of evaluation scales cannot substitute a full clinical interview but they serve to systematize the recollection of symptoms. On the other hand, instruments for screening bipolar disorder tend to have lower sensitivity.
Differential diagnosis. Bipolar disorder is classified by the International Classification of Diseases as a mental and behavioural disorder. Mental disorders that can have symptoms similar to those seen in bipolar disorder include schizophrenia, major depressive disorder, attention deficit hyperactivity disorder (ADHD), and certain personality disorders, such as borderline personality disorder. A key difference between bipolar disorder and borderline personality disorder is the nature of the mood swings; in contrast to the sustained changes to mood over days to weeks or longer, those of the latter condition (more accurately called emotional dysregulation) are sudden and often short-lived, and secondary to social stressors.
Bipolar spectrum. Bipolar spectrum disorders include: bipolar I disorder, bipolar II disorder, cyclothymic disorder and cases where subthreshold symptoms are found to cause clinically significant impairment or distress. These disorders involve major depressive episodes that alternate with manic or hypomanic episodes, or with mixed episodes that feature symptoms of both mood states. The concept of the bipolar spectrum is similar to that of Emil Kraepelin's original concept of manic depressive illness. Bipolar II disorder was established as a diagnosis in 1994 within DSM IV; though debate continues over whether it is a distinct entity, part of a spectrum, or exists at all. Criteria and subtypes. The DSM and the ICD characterize bipolar disorder as a spectrum of disorders occurring on a continuum. The DSM-5 and ICD-11 lists three specific subtypes: When relevant, specifiers for "peripartum onset" and "with rapid cycling" should be used with any subtype. Individuals who have subthreshold symptoms that cause clinically significant distress or impairment, but do not meet full criteria for one of the three subtypes may be diagnosed with other specified or unspecified bipolar disorder. Other specified bipolar disorder is used when a clinician chooses to explain why the full criteria were not met (e.g., hypomania without a prior major depressive episode). If the condition is thought to have a non-psychiatric medical cause, the diagnosis of "bipolar and related disorder due to another medical condition" is made, while "substance/medication-induced bipolar and related disorder" is used if a medication is thought to have triggered the condition.
Rapid cycling. Most people who meet criteria for bipolar disorder experience a number of episodes, on average 0.4 to 0.7 per year, lasting three to six months. "Rapid cycling", however, is a course specifier that may be applied to any bipolar subtype. It is defined as having four or more mood disturbance episodes within a one-year span. Rapid cycling is usually temporary but is common amongst people with bipolar disorder and affects 25.8–45.3% of them at some point in their life. These episodes are separated from each other by a remission (partial or full) for at least two months or a switch in mood polarity (i.e., from a depressive episode to a manic episode or vice versa). The definition of rapid cycling most frequently cited in the literature (including the DSM-V and ICD-11) is that of Dunner and Fieve: at least four major depressive, manic, hypomanic or mixed episodes during a 12-month period. The literature examining the pharmacological treatment of rapid cycling is sparse and there is no clear consensus with respect to its optimal pharmacological management. "Ultra rapid" and "ultradian" have been applied to faster-cycling types of bipolar disorder. People with the rapid cycling or faster-cycling subtypes of bipolar disorder tend to be more difficult to treat and less responsive to medications than other people with bipolar disorder.
Coexisting psychiatric conditions. The diagnosis of bipolar disorder can be complicated by coexisting (comorbid) psychiatric conditions including obsessive–compulsive disorder, substance-use disorder, eating disorders, attention deficit hyperactivity disorder, social phobia, premenstrual syndrome (including premenstrual dysphoric disorder), or panic disorder. A thorough longitudinal analysis of symptoms and episodes, assisted if possible by discussions with friends and family members, is crucial to establishing a treatment plan where these comorbidities exist. Children of parents with bipolar disorder more frequently have other mental health problems. Children. In the 1920s, Kraepelin noted that manic episodes are rare before puberty. In general, bipolar disorder in children was not recognized in the first half of the twentieth century. This issue diminished with an increased following of the DSM criteria in the last part of the twentieth century. The diagnosis of childhood bipolar disorder, while formerly controversial, has gained greater acceptance among childhood and adolescent psychiatrists. American children and adolescents diagnosed with bipolar disorder in community hospitals increased 4-fold reaching rates of up to 40% in 10 years around the beginning of the 21st century, while in outpatient clinics it doubled reaching 6%. Studies using DSM criteria show that up to 1% of youth may have bipolar disorder. The DSM-5 has established a diagnosis—disruptive mood dysregulation disorder—that covers children with long-term, persistent irritability that had at times been misdiagnosed as having bipolar disorder, distinct from irritability in bipolar disorder that is restricted to discrete mood episodes.
Adults. Bipolar on average, starts during adulthood. Bipolar 1, on average, starts at the age of 18 years old, and Bipolar 2 starts at age 22 years old on average. However, most delay seeking treatment for an average of 8 years after symptoms start. Bipolar is often misdiagnosed with other psychiatric disorders. There is no definitive association between race, ethnicity, or Socioeconomic status (SES). Adults with Bipolar report having a lower quality of life, even outside of a manic or depressive episode. Bipolar can put strain on marriage and other relationships, having a job, and everyday functioning. Bipolar is associated with having higher rates of unemployment. Most have trouble keeping a job, leading to trouble with healthcare access, leading to more decline in their mental health due to not receiving treatment such as medicine and therapy. Elderly.
Prevention. Attempts at prevention of bipolar disorder have focused on stress (such as childhood adversity or highly conflictual families) which, although not a diagnostically specific causal agent for bipolar, does place genetically and biologically vulnerable individuals at risk for a more severe course of illness. Longitudinal studies have indicated that full-blown manic stages are often preceded by a variety of prodromal clinical features, providing support for the occurrence of an at-risk state of the disorder when an early intervention might prevent its further development and/or improve its outcome. Management. The aim of management is to treat acute episodes safely with medication and work with the patient in long-term maintenance to prevent further episodes and optimise function using a combination of pharmacological and psychotherapeutic techniques. Hospitalization may be required especially with the manic episodes present in bipolar I. This can be voluntary or (local legislation permitting) involuntary. Long-term inpatient stays are now less common due to deinstitutionalization, although these can still occur. Following (or in lieu of) a hospital admission, support services available can include drop-in centers, visits from members of a community mental health team or an Assertive Community Treatment team, supported employment, patient-led support groups, and intensive outpatient programs. These are sometimes referred to as partial-inpatient programs. Compared to the general population, people with bipolar disorder are less likely to frequently engage in physical exercise. Exercise may have physical and mental benefits for people with bipolar disorder, but there is a lack of research.
Psychosocial. Psychotherapy aims to assist a person with bipolar disorder in accepting and understanding their diagnosis, coping with various types of stress, improving their interpersonal relationships, and recognizing prodromal symptoms before full-blown recurrence. Cognitive behavioral therapy (CBT), family-focused therapy, and psychoeducation have the most evidence for efficacy in regard to relapse prevention, while interpersonal and social rhythm therapy and cognitive-behavioral therapy appear the most effective in regard to residual depressive symptoms. Most studies have been based only on bipolar I, however, and treatment during the acute phase can be a particular challenge. Some clinicians emphasize the need to talk with individuals experiencing mania, to develop a therapeutic alliance in support of recovery. Medication. Medications are often prescribed to help improve symptoms of bipolar disorder. Medications approved for treating bipolar disorder including mood stabilizers, antipsychotics, and certain antidepressants. Sometimes a combination of medications may also be suggested. The choice of medications may differ depending on the bipolar disorder episode type or if the person is experiencing unipolar or bipolar depression. Other factors to consider when deciding on an appropriate treatment approach includes if the person has any comorbidities, their response to previous therapies, adverse effects, and the desire of the person to be treated.
Mood stabilizers. Lithium and the anticonvulsants carbamazepine, lamotrigine, and valproic acid are classed as mood stabilizers due to their effect on the mood states in bipolar disorder. Valproate and carbamazepine are teratogenic and should be avoided as a treatment in women of childbearing age, but discontinuation of these medications during pregnancy is associated with a high risk of relapse. Lithium is also tetratogenic in the first trimester, though it can be acceptable during this period after careful weighing of benefits and risks. The effectiveness of topiramate is unknown. Mood stabilizers are used for long-term maintenance but have not demonstrated the ability to quickly treat acute bipolar depression. Antipsychotics. Antipsychotic medications are effective for short-term treatment of bipolar manic episodes and appear to be superior to lithium and anticonvulsants for this purpose. Atypical antipsychotics such as lurasidone and clozapine are also indicated for bipolar depression refractory to treatment with mood stabilizers. Olanzapine is effective in preventing relapses, although the supporting evidence is weaker than the evidence for lithium. A 2006 review found that haloperidol was an effective treatment for acute mania, limited data supported no difference in overall efficacy between haloperidol, olanzapine or risperidone, and that it could be less effective than aripiprazole.
Antidepressants. Antidepressant monotherapy is not recommended in the treatment of bipolar disorder and does not provide any benefit over mood stabilizers. Atypical antipsychotic medications (e.g., aripiprazole) are preferred over antidepressants to augment the effects of mood stabilizers due to the lack of efficacy of antidepressants in bipolar disorder. Treatment of bipolar disorder using antidepressants may carry a risk of affective switches where a person switches from depression to manic or hypomanic phases or mixed states. There may also be a risk of accelerating cycling between phases when antidepressants are used in bipolar disorder. The risk of affective switches is higher in bipolar I depression; antidepressants are generally avoided in bipolar I disorder or only used with mood stabilizers when they are deemed necessary. Whether modern antidepressants cause mania or cycle acceleration in bipolar disorder is highly controversial, as is whether antidepressants provide any benefit over mood stabilizers alone.
Combined treatment approaches. Antipsychotics and mood stabilizers used together are quicker and more effective at treating mania than either class of drug used alone. Some analyses indicate antipsychotics alone are also more effective at treating acute mania. A first-line treatment for depression in bipolar disorder is a combination of olanzapine and fluoxetine. Other drugs. Short courses of benzodiazepines are used in addition to other medications for calming effect until mood stabilizing become effective. Electroconvulsive therapy (ECT) is an effective form of treatment for acute mood disturbances in those with bipolar disorder, especially when psychotic or catatonic features are displayed. ECT is also recommended for use in pregnant women with bipolar disorder. It is unclear if ketamine (a common general dissociative anesthetic used in surgery) is useful in bipolar disorder. Gabapentin and pregabalin are not proven to be effective for treating bipolar disorder. Children. Treating bipolar disorder in children involves medication and psychotherapy. The literature and research on the effects of psychosocial therapy on bipolar spectrum disorders are scarce, making it difficult to determine the efficacy of various therapies. Mood stabilizers and atypical antipsychotics are commonly prescribed. Among the former, lithium is the only compound approved by the FDA for children. Psychological treatment combines normally education on the disease, group therapy, and cognitive behavioral therapy. Long-term medication is often needed.
Resistance to treatment. The poor response from some bipolar patients to treatment has given evidence to the concept of treatment-resistant bipolar disorder. Guidelines to the definition of treatment-resistant bipolar disorder and evidence-based options for its management were reviewed in 2020. Management of obesity. A large proportion (approximately 68%) of people who seek treatment for bipolar disorder are obese or overweight and managing obesity is important for reducing the risk of other health conditions that are associated with obesity. Management approaches include non-pharmacological, pharmacological, and surgical. Examples of non-pharmacological include dietary interventions, exercise, behavioral therapies, or combined approaches. Pharmacological approaches include weight-loss medications or changing medications already being prescribed. Some people with bipolar disorder who have obesity may also be eligible for bariatric surgery. The effectiveness of these various approaches to improving or managing obesity in people with bipolar disorder is not clear.
Prognosis. A lifelong condition with periods of partial or full recovery in between recurrent episodes of relapse, bipolar disorder is considered to be a major health problem worldwide because of the increased rates of disability and premature mortality. It is also associated with co-occurring psychiatric and medical problems, higher rates of death from natural causes (e.g., cardiovascular disease), and high rates of initial under- or misdiagnosis, causing a delay in appropriate treatment and contributing to poorer prognoses. When compared to the general population, people with bipolar disorder also have higher rates of other serious medical comorbidities including diabetes mellitus, respiratory diseases, HIV, and hepatitis C virus infection. After a diagnosis is made, it remains difficult to achieve complete remission of all symptoms with the currently available psychiatric medications and symptoms often become progressively more severe over time. Compliance with medications is one of the most significant factors that can decrease the rate and severity of relapse and have a positive impact on overall prognosis. However, the types of medications used in treating BD commonly cause side effects and more than 75% of individuals with BD inconsistently take their medications for various reasons. Of the various types of the disorder, rapid cycling (four or more episodes in one year) is associated with the worst prognosis due to higher rates of self-harm and suicide. Individuals diagnosed with bipolar who have a family history of bipolar disorder are at a greater risk for more frequent manic/hypomanic episodes. Early onset and psychotic features are also associated with worse outcomes, as well as subtypes that are nonresponsive to lithium.
Early recognition and intervention also improve prognosis as the symptoms in earlier stages are less severe and more responsive to treatment. Onset after adolescence is connected to better prognoses for both genders, and being male is a protective factor against higher levels of depression. For women, better social functioning before developing bipolar disorder and being a parent are protective towards suicide attempts. Functioning. Changes in cognitive processes and abilities are seen in mood disorders, with those of bipolar disorder being greater than those in major depressive disorder. These include reduced attentional and executive capabilities and impaired memory. People with bipolar disorder often experience a decline in cognitive functioning during (or possibly before) their first episode, after which a certain degree of cognitive dysfunction typically becomes permanent, with more severe impairment during acute phases and moderate impairment during periods of remission. As a result, two-thirds of people with BD continue to experience impaired psychosocial functioning in between episodes even when their mood symptoms are in full remission. A similar pattern is seen in both BD-I and BD-II, but people with BD-II experience a lesser degree of impairment.
When bipolar disorder occurs in children, it severely and adversely affects their psychosocial development. Children and adolescents with bipolar disorder have higher rates of significant difficulties with substance use disorders, psychosis, academic difficulties, behavioral problems, social difficulties, and legal problems. Cognitive deficits typically increase over the course of the illness. Higher degrees of impairment correlate with the number of previous manic episodes and hospitalizations, and with the presence of psychotic symptoms. Early intervention can slow the progression of cognitive impairment, while treatment at later stages can help reduce distress and negative consequences related to cognitive dysfunction. Despite the overly ambitious goals that are frequently part of manic episodes, symptoms of mania undermine the ability to achieve these goals and often interfere with an individual's social and occupational functioning. One-third of people with BD remain unemployed for one year following a hospitalization for mania. Depressive symptoms during and between episodes, which occur much more frequently for most people than hypomanic or manic symptoms over the course of illness, are associated with lower functional recovery in between episodes, including unemployment or underemployment for both BD-I and BD-II. However, the course of illness (duration, age of onset, number of hospitalizations, and the presence or not of rapid cycling) and cognitive performance are the best predictors of employment outcomes in individuals with bipolar disorder, followed by symptoms of depression and years of education.
Recovery and recurrence. A naturalistic study in 2003 by Tohen and coworkers from the first admission for mania or mixed episode (representing the hospitalized and therefore most severe cases) found that 50% achieved syndromal recovery (no longer meeting criteria for the diagnosis) within six weeks and 98% within two years. Within two years, 72% achieved symptomatic recovery (no symptoms at all) and 43% achieved functional recovery (regaining of prior occupational and residential status). However, 40% went on to experience a new episode of mania or depression within 2 years of syndromal recovery, and 19% switched phases without recovery. Symptoms preceding a relapse (prodromal), especially those related to mania, can be reliably identified by people with bipolar disorder. There have been intents to teach patients coping strategies when noticing such symptoms with encouraging results. Suicide. Bipolar disorder can cause suicidal ideation that leads to suicide attempts. Individuals whose bipolar disorder begins with a depressive or mixed affective episode seem to have a poorer prognosis and an increased risk of suicide. One out of two people with bipolar disorder attempt suicide at least once during their lifetime and many attempts are successfully completed. The annual average suicide rate is 0.4–1.4%, which is 30 to 60 times greater than that of the general population. The number of deaths from suicide in bipolar disorder is between 18 and 25 times higher than would be expected in similarly aged people without bipolar disorder. The lifetime risk of suicide is much higher in those with bipolar disorder, with an estimated 34% of people attempting suicide and 15–20% dying by suicide.
Risk factors for suicide attempts and death from suicide in people with bipolar disorder include older age, prior suicide attempts, a depressive or mixed index episode (first episode), a manic index episode with psychotic symptoms, hopelessness or psychomotor agitation present during the episodes, co-existing anxiety disorder, a first degree relative with a mood disorder or suicide, interpersonal conflicts, occupational problems, bereavement or social isolation. Epidemiology. Bipolar disorder is the sixth leading cause of disability worldwide and has a lifetime prevalence of about 1 to 3% in the general population. However, a reanalysis of data from the National Epidemiological Catchment Area survey in the United States suggested that 0.8% of the population experience a manic episode at least once (the diagnostic threshold for bipolar I) and a further 0.5% have a hypomanic episode (the diagnostic threshold for bipolar II or cyclothymia). Including sub-threshold diagnostic criteria, such as one or two symptoms over a short time-period, an additional 5.1% of the population, adding up to a total of 6.4%, were classified as having a bipolar spectrum disorder. A more recent analysis of data from a second US National Comorbidity Survey found that 1% met lifetime prevalence criteria for bipolar I, 1.1% for bipolar II, and 2.4% for subthreshold symptoms. Estimates vary about how many children and young adults have bipolar disorder. These estimates range from 0.6 to 15% depending on differing settings, methods, and referral settings, raising suspicions of overdiagnosis. One meta-analysis of bipolar disorder in young people worldwide estimated that about 1.8% of people between the ages of seven and 21 have bipolar disorder. Similar to adults, bipolar disorder in children and adolescents is thought to occur at a similar frequency in boys and girls.
There are conceptual and methodological limitations and variations in the findings. Prevalence studies of bipolar disorder are typically carried out by lay interviewers who follow fully structured/fixed interview schemes; responses to single items from such interviews may have limited validity. In addition, diagnoses (and therefore estimates of prevalence) vary depending on whether a categorical or spectrum approach is used. This consideration has led to concerns about the potential for both underdiagnosis and overdiagnosis. The incidence of bipolar disorder is similar in men and women as well as across different cultures and ethnic groups. A 2000 study by the World Health Organization found that prevalence and incidence of bipolar disorder are very similar across the world. Age-standardized prevalence per 100,000 ranged from 421.0 in South Asia to 481.7 in Africa and Europe for men and from 450.3 in Africa and Europe to 491.6 in Oceania for women. However, severity may differ widely across the globe. Disability-adjusted life year rates, for example, appear to be higher in developing countries, where medical coverage may be poorer and medication less available. Within the United States, Asian Americans have significantly lower rates than their African American and European American counterparts. In 2017, the Global Burden of Disease Study estimated there were 4.5 million new cases and a total of 45.5 million cases globally.
History. In the early 1800s, French psychiatrist Jean-Étienne Dominique Esquirol's lypemania, one of his affective monomanias, was the first elaboration on what was to become modern depression. The basis of the current conceptualization of bipolar illness can be traced back to the 1850s. In 1850, Jean-Pierre Falret described "circular insanity" (', ); the lecture was summarized in 1851 in the ' ("Hospital Gazette"). Three years later, in 1854, Jules-Gabriel-François Baillarger (1809–1890) described to the French Imperial Académie Nationale de Médecine a biphasic mental illness causing recurrent oscillations between mania and melancholia, which he termed (, "madness in double form"). Baillarger's original paper, "", appeared in the medical journal "Annales médico-psychologiques" ("Medico-psychological annals") in 1854. These concepts were developed by the German psychiatrist Emil Kraepelin (1856–1926), who, using Kahlbaum's concept of cyclothymia, categorized and studied the natural course of untreated bipolar patients. He coined the term "manic depressive psychosis", after noting that periods of acute illness, manic or depressive, were generally punctuated by relatively symptom-free intervals where the patient was able to function normally.
The term "manic–depressive "reaction"" appeared in the first version of the DSM in 1952, influenced by the legacy of Adolf Meyer. Subtyping into "unipolar" depressive disorders and bipolar disorders has its origin in Karl Kleist's concept – since 1911 – of unipolar and bipolar affective disorders, which was used by Karl Leonhard in 1957 to differentiate between unipolar and bipolar disorder in depression. These subtypes have been regarded as separate conditions since publication of the DSM-III. The subtypes bipolar II and rapid cycling have been included since the DSM-IV, based on work from the 1970s by David Dunner, Elliot Gershon, Frederick Goodwin, Ronald Fieve, and Joseph Fleiss. Society and culture. Cost. The United States spent approximately $202.1 billion on people diagnosed with bipolar I disorder (excluding other subtypes of bipolar disorder and undiagnosed people) in 2015. One analysis estimated that the United Kingdom spent approximately £5.2 billion on the disorder in 2007. In addition to the economic costs, bipolar disorder is a leading cause of disability and lost productivity worldwide. People with bipolar disorder are generally more disabled, have a lower level of functioning, longer duration of illness, and increased rates of work absenteeism and decreased productivity when compared to people experiencing other mental health disorders. The decrease in the productivity seen in those who care for people with bipolar disorder also significantly contributes to these costs.
Advocacy. There are widespread issues with social stigma, stereotypes, and prejudice against individuals with a diagnosis of bipolar disorder. In 2000, actress Carrie Fisher went public with her bipolar disorder diagnosis. She became one of the most well-recognized advocates for people with bipolar disorder in the public eye and fiercely advocated to eliminate the stigma surrounding mental illnesses, including bipolar disorder. Stephen Fried, who has written extensively on the topic, noted that Fisher helped to draw attention to the disorder's chronicity, relapsing nature, and that bipolar disorder relapses do not indicate a lack of discipline or moral shortcomings. Since being diagnosed at age 37, actor Stephen Fry has pushed to raise awareness of the condition, with his 2006 documentary "". In an effort to ease the social stigma associated with bipolar disorder, the orchestra conductor Ronald Braunstein cofounded the ME/2 Orchestra with his wife Caroline Whiddon in 2011. Braunstein was diagnosed with bipolar disorder in 1985 and his concerts with the ME/2 Orchestra were conceived in order to create a welcoming performance environment for his musical colleagues, while also raising public awareness about mental illness.
Notable cases. Numerous authors have written about bipolar disorder and many successful people have openly discussed their experience with it. Kay Redfield Jamison, a clinical psychologist and professor of psychiatry at the Johns Hopkins University School of Medicine, profiled her own bipolar disorder in her memoir "An Unquiet Mind" (1995). It is likely that Grigory Potemkin, Russian statesman and alleged husband of Catherine the Great, suffered from some kind of bipolar disorder. Several celebrities have also publicly shared that they have bipolar disorder; in addition to Carrie Fisher and Stephen Fry these include Catherine Zeta-Jones, Mariah Carey, Kanye West, Jane Pauley, Demi Lovato, Selena Gomez, and Russell Brand. Media portrayals. Several dramatic works have portrayed characters with traits suggestive of the diagnosis which have been the subject of discussion by psychiatrists and film experts alike. In "Mr. Jones" (1993), (Richard Gere) swings from a manic episode into a depressive phase and back again, spending time in a psychiatric hospital and displaying many of the features of the syndrome. In "The Mosquito Coast" (1986), Allie Fox (Harrison Ford) displays some features including recklessness, grandiosity, increased goal-directed activity and mood lability, as well as some paranoia. Psychiatrists have suggested that Willy Loman, the main character in Arthur Miller's classic play "Death of a Salesman", has bipolar disorder.
The 2009 drama "90210" featured a character, Silver, who was diagnosed with bipolar disorder. Stacey Slater, a character from the BBC soap "EastEnders", has been diagnosed with the disorder. The storyline was developed as part of the BBC's Headroom campaign. The Channel 4 soap "Brookside" had earlier featured a story about bipolar disorder when the character Jimmy Corkhill was diagnosed with the condition. 2011 Showtime's political thriller drama "Homeland" protagonist Carrie Mathison has bipolar disorder, which she has kept secret since her school days. The 2014 ABC medical drama, "Black Box", featured a world-renowned neuroscientist with bipolar disorder. In the TV series "Dave", the eponymous main character, played by Lil Dicky as a fictionalized version of himself, is an aspiring rapper. Lil Dicky's real-life hype man GaTa also plays himself. In one episode, after being off his medication and having an episode, GaTa tearfully confesses to having bipolar disorder. GaTa has bipolar disorder in real life but, like his character in the show, he is able to manage it with medication.
Creativity. A link between mental illness and professional success or creativity has been suggested, including in accounts by Socrates, Seneca the Younger, and Cesare Lombroso. Despite prominence in popular culture, the link between creativity and bipolar has not been rigorously studied. This area of study also is likely affected by confirmation bias. Some evidence suggests that some heritable component of bipolar disorder overlaps with heritable components of creativity. Probands of people with bipolar disorder are more likely to be professionally successful, as well as to demonstrate temperamental traits similar to bipolar disorder. Furthermore, while studies of the frequency of bipolar disorder in creative population samples have been conflicting, full-blown bipolar disorder in creative samples is rare. Research. Research directions for bipolar disorder in children include optimizing treatments, increasing the knowledge of the genetic and neurobiological basis of the pediatric disorder and improving diagnostic criteria. Some treatment research suggests that psychosocial interventions that involve the family, psychoeducation, and skills building (through therapies such as CBT, DBT, and IPSRT) can benefit in addition to pharmacotherapy.
Blitz Blitz, German for "lightning", may refer to:
Burt Lancaster Burton Stephen Lancaster (November 2, 1913 – October 20, 1994) was an American actor. Initially known for playing tough guys with a tender heart, he went on to achieve success with more complex and challenging roles over a 45-year career in films and television series. He was a four-time nominee for the Academy Award for Best Actor (winning once), and he also won two BAFTA Awards and one Golden Globe Award for Best Lead Actor. The American Film Institute ranks Lancaster as of the greatest male stars of classic Hollywood cinema. Lancaster performed as a circus acrobat in the 1930s. At the age of 32, and after serving in World War II, he landed a role in a Broadway play and drew the attention of a Hollywood agent. His appearance in film noir "The Killers" in 1946 alongside Ava Gardner was a critical success and launched both of their careers. In 1948, Lancaster starred alongside Barbara Stanwyck in the commercially and critically acclaimed film "Sorry, Wrong Number", where he portrayed the husband to her bedridden invalid character. In 1953, Lancaster played the illicit lover of Deborah Kerr in the military drama "From Here to Eternity". A box office smash, it won eight Academy Awards, including Best Picture, and landed a Best Actor nomination for Lancaster.
Later in the 1950s, he starred in "The Rainmaker" (1956), with Katharine Hepburn, earning a Best Actor Golden Globe nomination, and in 1957 he starred in "Gunfight at the O.K. Corral" (1957) with frequent co-star Kirk Douglas. During the 1950s, his production company, Hecht-Hill-Lancaster, was highly successful, with Lancaster acting in films such as: "Trapeze" (1956), a box office smash in which he used his acrobatic skills and for which he won the Silver Bear for Best Actor; "Sweet Smell of Success" (1957), a dark drama today considered a classic; "Run Silent, Run Deep" (1958), a WWII submarine drama with Clark Gable; and "Separate Tables" (1958), a hotel-set drama which received seven Oscar nominations. In the early 1960s, Lancaster starred in a string of critically successful films, each in very disparate roles. Playing a charismatic biblical con-man in "Elmer Gantry" in 1960 won him the Academy Award and the Golden Globe for Best Actor. He played a Nazi war criminal in 1961 in the all-star, war-crime-trial film, "Judgment at Nuremberg". Playing a bird expert prisoner in "Birdman of Alcatraz" in 1962, he earned the BAFTA Award for Best Foreign Actor and his third Oscar nomination. In 1963, Lancaster traveled to Italy to star as an Italian prince in Visconti's epic period drama "The Leopard". In 1964, he played a US Air Force General who, opposed by a Colonel played by Douglas, tries to overthrow the President in "Seven Days in May". Then, in 1966, he played an explosives expert in the western "The Professionals". Although the reception of his 1968 film "The Swimmer" was initially lackluster upon release, in the years after it has grown in stature critically and attained a cult following.
In 1970, Lancaster starred in the box-office hit, air-disaster drama "Airport". In 1974, he again starred in a Visconti film, "Conversation Piece". He experienced a career resurgence in 1980 with the crime-romance "Atlantic City", winning the BAFTA for Best Actor and landing his fourth Oscar nomination. Starting in the late 1970s, he also appeared in television mini-series, including the award-winning "Separate but Equal" with Sidney Poitier. He continued acting into his late 70s, until a stroke in 1990 forced him to retire; four years later he died from a heart attack. His final film role was in the Oscar-nominated "Field of Dreams". Early life. Lancaster was born on November 2, 1913, in New York City, at his parents' home at 209 East 106th Street, the son of Elizabeth ("née" Roberts) and mailman James Lancaster. Both of his parents were Protestants of working-class background. All four of his grandparents were Scots-Irish immigrants from the province of Ulster, Ireland. His maternal side was from Belfast, the descendants of English dissenters who had colonized Ireland as part of the Plantation of Ulster.
Lancaster grew up in East Harlem, New York City. He developed a great interest and skill in gymnastics while attending DeWitt Clinton High School, where he was a basketball star. Before he graduated from DeWitt Clinton, his mother died of a cerebral hemorrhage. Lancaster was accepted by New York University with an athletic scholarship, but dropped out. Circus career. At the age of 9, Lancaster met Nick Cravat with whom he developed a lifelong partnership. Together, they learned to act in local theatre productions and circus arts at Union Settlement, one of the city's oldest settlement houses. In the 1930s, they formed the acrobat duo "Lang and Cravat" and soon joined the Kay Brothers circus. However, in 1939, an injury forced Lancaster to give up the profession, with great regret. He then found temporary work, first as a salesman for Marshall Fields and then as a singing waiter in various restaurants. World War II service. After the United States entered World War II, Lancaster joined the United States Army in January 1943 and performed with the Army's 21st Special Services Division, one of the military groups organized to follow the troops on the ground and provide USO entertainment to keep up morale. He served in the Fifth Army in Italy under General Mark Clark from 1943 to 1945. He was discharged October 1945 and was an entertainment specialist with the rank of technician fifth grade.
Acting career. Broadway. Lancaster returned to New York after his Army service. Although initially unenthusiastic about acting, Lancaster was encouraged to audition for a Broadway play by a producer who saw him in an elevator while he was visiting his then-girlfriend at work. The audition was successful and Lancaster was cast in Harry Brown's "A Sound of Hunting" (1945). The show only ran three weeks, but his performance attracted the interest of a Hollywood agent, Harold Hecht. Lancaster had other offers but Hecht promised him the opportunity to produce their own movies within five years of hitting Hollywood. Through Hecht, Lancaster was brought to the attention of producer Hal B. Wallis. Lancaster left New York and moved to Los Angeles. Wallis signed him to a non-exclusive eight-movie contract. Hal Wallis. Lancaster's first filmed movie was "Desert Fury" for Wallis in 1947, where Lancaster was billed after John Hodiak and Lizabeth Scott. It was directed by Lewis Allen. Then producer Mark Hellinger approached him to star in 1946's "The Killers", which was completed and released prior to "Desert Fury". Directed by Robert Siodmak, it was a great commercial and critical success and launched Lancaster and his co-star Ava Gardner to stardom. It has since come to be regarded as a classic.
Hellinger used Lancaster again on "Brute Force" in 1947, a prison drama written by Richard Brooks and directed by Jules Dassin. It was also well received. Wallis released his films through Paramount, and so Lancaster and other Wallis contractees made cameos in "Variety Girl" in 1947. Lancaster's next film was a thriller for Wallis in 1947, "I Walk Alone", co-starring Lizabeth Scott and a young Kirk Douglas, who was also under contract to Wallis. "Variety" listed it as one of the top grossers of the year, taking in more than $2 million. In 1948, Lancaster had a change of pace with the film adaptation of Arthur Miller's "All My Sons", made at Universal Pictures with Edward G. Robinson. His third film for Wallis was an adaptation of "Sorry, Wrong Number" in 1948, with Barbara Stanwyck. Norma Productions. Hecht kept to his promise to Lancaster to turn producer. The two of them formed a company, Norma Productions, and did a deal with Universal to make a thriller about a disturbed G.I. in London, "Kiss the Blood Off My Hands" in 1948, with Joan Fontaine and directed by Norman Foster. It made a profit of only $50,000, but was critically acclaimed.
Back in Hollywood, Lancaster made another film noir with Siodmak, "Criss Cross", in 1949. It was originally going to be produced by Hellinger and when Hellinger died, another took over. Tony Curtis made an early appearance. Lancaster appeared in a fourth picture for Wallis, "Rope of Sand", in 1949. Norma Productions signed a three-picture deal with Warner Bros. The first was 1950's "The Flame and the Arrow", a swashbuckler movie, in which Lancaster drew on his circus skills. Nick Cravat had a supporting role and the film was a huge commercial success, making $6 million. It was Warners' most popular film of the year and established an entirely new image for Lancaster. Lancaster was borrowed by 20th Century Fox for "Mister 880" in 1950, a comedy crime romance film with Edmund Gwenn. MGM put him in a popular Western, "Vengeance Valley" in 1951, then he went to Warners to play the title role in the biopic "Jim Thorpe – All-American", also in 1951. Halburt. Norma signed a deal with Columbia Pictures to make two films through a Norma subsidiary, Halburt. The first film was 1951's "Ten Tall Men", where Lancaster was a member of the French Foreign Legion. Robert Aldrich worked on the movie as a production manager.
The second was 1952's "The First Time", a comedy which was the directorial debut of Frank Tashlin. It was meant to star Lancaster but he wound up not appearing in the filmthe first of their productions in which he did not act. Hecht-Lancaster Productions. In 1951, the actor/producer duo changed the company's name to Hecht-Lancaster Productions. The first film under the new name was another swashbuckler: 1952's "The Crimson Pirate", directed by Siodmak. Again, co-starring Nick Cravat, it was extremely popular. Taking the premise of The Flame and the Arrow a step further, it allowed the pair to, not only emphasise the absurdity of the story with more spectacle and comical situations but to demonstrate they were able to perform their own circus skills-based stunts without relying on stuntmen quite as much a most Hollywood stars. As if to down play this, Lancaster himself speaks to the audience in the opening scene over footage of Lancaster performing a dangerous rope swing from one of his pirate ship's masts to the other. "…in a pirate world, believe only what you see." The footage is then reversed to show a near impossible backwards swing to the first mast again, from which he proclaims "No, believe HALF of what you see."
Lancaster changed pace once more by doing a straight dramatic part in 1952's "Come Back, Little Sheba", based on a Broadway hit, with Shirley Booth, produced by Wallis and directed by Daniel Mann. Alternating with adventure films, he went into "South Sea Woman" in 1952 at Warners. Part of the Norma-Warners contract was that Lancaster had to appear in some non-Norma films, of which this was one. In 1954, for his own company, Lancaster produced and starred in "His Majesty O'Keefe", a South Sea island tale shot in Fiji. It was co-written by James Hill, who would soon become a part of the Hecht-Lancaster partnership. United Artists. Hecht and Lancaster left Warners for United Artists, for what began as a two-picture deal, the first of which was to be 1954's "Apache", starring Lancaster as a Native American. They followed it with another Western in 1954, "Vera Cruz", co-starring Gary Cooper and produced by Hill. Both films were directed by Robert Aldrich and were hugely popular. United Artists signed Hecht-Lancaster to a multi-picture contract, to make seven films over two years. These included films in which Lancaster did not act. Their first was "Marty" in 1955, based on Paddy Chayefsky's TV play starring Ernest Borgnine and directed by Delbert Mann. It won both the Best Picture Oscar and the Palme d'Or award at Cannes and Borgnine an Best Actor Oscar. It also earned $2 million on a budget of $350,000. "Vera Cruz" had been a huge success, but "Marty" secured Hecht-Lancaster as one of the most successful independent production companies in Hollywood at the time. "Marty" star Borgnine was under contract to Hecht-Lancaster and was unhappy about his lack of upcoming roles, especially after only receiving some seven lines in 1957's "Sweet Smell of Success" and half of his normal pay for "Marty". He eventually sued for breach of contract to gain back some of this money in 1957.
Without Hill, Hecht and Lancaster produced "The Kentuckian" in 1955. It was directed by Lancaster in his directorial debut, and he also played a lead role. Lancaster disliked directing and only did it once more, on 1974's "The Midnight Man". Lancaster still had commitments with Wallis, and made "The Rose Tattoo" for him in 1955, starring with Anna Magnani and Daniel Mann directing. It was very popular at the box office and critically acclaimed, winning Magnani an Oscar. Hecht-Hill-Lancaster. In 1955, Hill was made an equal partner in Hecht-Lancaster, with his name added to the production company. Hecht-Hill-Lancaster (HHL) released their first film "Trapeze" in 1956, with Lancaster performing many of his own stunts. The film, co-starring Tony Curtis and Gina Lollobrigida, went on to become the production company's top box office success, and United Artists expanded its deal with HHL. In 1956, Lancaster and Hecht partnered with Loring Buzzell and entered the music industry with the music publishing companies Leigh Music, Hecht-Lancaster & Buzzell Music, Calyork Music and Colby Music and the record labels Calyork Records and Maine Records.
The HHL team impressed Hollywood with its success; as "Life" wrote in 1957, "[a]fter the independent production of a baker's dozen of pictures, it has yet to have its first flop ... (They were also good pictures.)." In late 1957, they announced they would make ten films worth $14 million in 1958. Lancaster made two films for Wallis to complete his eight-film commitment for that contract: "The Rainmaker" (1956) with Katharine Hepburn, which earned Lancaster a Golden Globe nomination for Best Actor; and "Gunfight at the O.K. Corral" (1957) with Kirk Douglas, which was a huge commercial hit directed by John Sturges. Lancaster re-teamed with Tony Curtis in 1957 for "Sweet Smell of Success", a co-production between Hecht-Hill-Lancaster and Curtis' own company with wife Janet Leigh, Curtleigh Productions. The movie, directed by Alexander Mackendrick, was a critical success but a commercial disappointment. Over the years it has come to be regarded as one of Lancaster's greatest films. HHL produced seven additional films in the late 1950s. Four starred Lancaster: "Run Silent, Run Deep" (1958), a Robert Wise directed war film with Clark Gable, which was mildly popular; "Separate Tables" (1958) a hotel-set drama with Kerr and Rita Hayworth (who married James Hill), which received an Oscar nomination for Best Picture and Oscar awards for lead actor David Niven and supporting actress Wendy Hiller, and was both a critical and commercial success; "The Devil's Disciple" (1959), with Douglas and Laurence Olivier, which lost money (and saw Lancaster fire Mackendrick during shooting); and the Western "The Unforgiven" (1960), with Audrey Hepburn, which was a critical and commercial disappointment.
Three were made without Lancaster, all of which lost money: "The Bachelor Party" (1957), from another TV play by Chayefsky, and directed by Delbert Mann; "Take a Giant Step" (1959), about a black student; and "Summer of the Seventeenth Doll" (1960), from an Australian play, shot on location in Australia and Britain. Lancaster was originally announced as the lead for "Doll" but did not appear in the final film. The Hecht-Hill-Lancaster Productions company dissolved in 1960 after Hill ruptured his relationship with both Hecht and Lancaster. Hill went on to produce a single additional film, "The Happy Thieves", in a new production company, Hillworth Productions, co-owned with his wife Rita Hayworth. Hecht and Lancaster. Lancaster played the title role in "Elmer Gantry" (1960), written and directed by Richard Brooks for United Artists. The film received five Academy Award nominations, including Best Picture and Best Actor. Lancaster won the 1960 Academy Award for Best Actor, a Golden Globe Award, and the New York Film Critics Award for his performance.
Hecht and Lancaster worked together on "The Young Savages" (1961), directed by John Frankenheimer and produced by Hecht. Sydney Pollack worked as a dialogue coach. Lancaster starred in "Judgment at Nuremberg" (1961) for Stanley Kramer, alongside Spencer Tracy, Richard Widmark and a number of other stars. The film was both a commercial and critical success, receiving eleven Oscar nominations, including Best Picture. He then did another film with Hecht and Frankenheimer (replacing Charles Crichton), "Birdman of Alcatraz" (1962), a largely fictionalized biography. In it he plays Robert Stroud, a federal prisoner incarcerated for life for two murders, who begins to collect birds and over time becomes an expert in bird diseases, even publishing a book. The film shows Stroud transferred to the maximum security Alcatraz prison where he is not allowed to keep birds and as he ages he gets married, markets bird remedies, helps stop a prison rebellion, and writes a book on the history of the U.S. penal system, but never gets paroled.
The sympathetic performance earned Lancaster a Best Actor Oscar nomination, a BAFTA Award for Best Actor, and a Golden Globe nomination for Best Actor in a Dramatic Role. Hecht went on to produce five films without Lancaster's assistance, through his company Harold Hecht Films Productions between 1961 and 1967, including another Academy Award winner, "Cat Ballou", starring Lee Marvin and Jane Fonda. Collaborations with younger filmmakers. Lancaster made "A Child Is Waiting" (1963) with Judy Garland. It was produced by Kramer and directed by John Cassavetes. He went to Italy to star in "The Leopard" (1963) for Luchino Visconti, co-starring Alain Delon and Claudia Cardinale. It was one of Lancaster's favorite films and was a big hit in France but failed in the US (though the version released was much truncated). He had a small role in "The List of Adrian Messenger" (1963) for producer/star Kirk Douglas, and then did two for Frankenheimer: "Seven Days in May" (1964), a political thriller with Douglas, and "The Train" (1964), a World War Two action film (Lancaster had Frankenheimer replace Arthur Penn several days into filming).
Lancaster starred in "The Hallelujah Trail" (1965), a comic Western produced and directed by John Sturges which failed to recoup its large cost. He had a big hit with "The Professionals" (1966), a Western directed by Brooks and also starring Lee Marvin. In 1966, at the age of 52, Lancaster appeared nude in director Frank Perry's film "The Swimmer" (1968), in what the critic Roger Ebert called "his finest performance". Prior to working on "The Swimmer", Lancaster was terrified of the water because he did not know how to swim. In preparation for the film, he took swimming lessons from UCLA swim coach Bob Horn. Filming was difficult and clashes between Lancaster and Perry led to Sydney Pollack coming in to do some filming. The film was not released until 1968, when it proved to be a commercial failure, though Lancaster remained proud of the movie and his performance. Norlan Productions. In 1967, Lancaster formed a new partnership with Roland Kibbee, who had already worked as a writer on five Lancaster projects: "Ten Tall Men", "The Crimson Pirate", "Three Sailors and a Girl" (in which Lancaster made a cameo appearance), "Vera Cruz", and "The Devil's Disciple".
Through Norlan Productions, Lancaster and Kibbee produced "The Scalphunters" in 1968, directed by Sydney Pollack. Lancaster followed it with another film from Pollack, "Castle Keep" in 1969, which was a big flop. So was "The Gypsy Moths", for Frankenheimer, also in 1969. 1970s. Lancaster had one of the biggest successes of his career with "Airport" in 1970, starring alongside Dean Martin, George Kennedy, Van Heflin, Helen Hayes, Maureen Stapleton, Barbara Hale, Jean Seberg, and Jacqueline Bisset. The Ross Hunter film received nine Academy Award nominations, including one for Best Picture. It became one of the biggest box-office hits of 1970 and, at that time, reportedly the highest-grossing film in the history of Universal Pictures. He then went into a series of Westerns: "Lawman" in 1971, directed by Michael Winner; "Valdez Is Coming" in 1971, for Norlan; and "Ulzana's Raid" in 1972, directed by Aldrich and produced by himself and Hecht. None were particularly popular but "Ulzana's Raid" has become a cult film.
Lancaster did two thrillers, both 1973: "Scorpio" with Winner and "Executive Action". Lancaster returned to directing in 1974 with "The Midnight Man", which he also wrote and produced with Kibee. He made a second film with Visconti, "Conversation Piece" in 1974 and played the title role in the TV series "Moses the Lawgiver", also in 1974. Lancaster was one of many names in 1975's "1900", directed by Bernardo Bertolucci, and he had a cameo in 1976's "Buffalo Bill and the Indians, or Sitting Bull's History Lesson" for Robert Altman. He played Shimon Peres in the TV movie "Victory at Entebbe" in 1977 and had a supporting role in "The Cassandra Crossing" in 1976. He made a fourth and final film with Aldrich, "Twilight's Last Gleaming" in 1977, and had the title role in 1977's "The Island of Dr. Moreau". Lancaster was top-billed in "Go Tell the Spartans" in 1978, a Vietnam War film; Lancaster admired the script so much that he took a reduced fee and donated money to help the movie to be completed. He was in "Zulu Dawn" in 1979. 1980s.
Lancaster began the 1980s with a highly acclaimed performance alongside Susan Sarandon in "Atlantic City" in 1980, directed by Louis Malle. The film received five Oscar nominations, including Best Picture and a Best Actor nomination for Lancaster. He had key roles in "Cattle Annie and Little Britches" in 1981, "The Skin" in 1982 with Cardinale, "Marco Polo", also in 1982, and "Local Hero" in 1983. By now, Lancaster was mostly a character actor in features, as in "The Osterman Weekend" in 1983, but he was the lead in the TV movie "Scandal Sheet" in 1985. He was in "Little Treasure" in 1985, directed by Alan Sharp, who had written "Ulzana's Raid"; "On Wings of Eagles" for TV in 1986, as Bull Simons; 1986's made for TV "Barnum" starred him in the title role; "Tough Guys" reunited him on the big screen with Kirk Douglas in 1986; "" (in German Väter und Söhne – Eine deutsche Tragödie) in 1986 for German TV; 1987's "Control" made in Italy; "Rocket Gibraltar" in 1988, and "The Jeweller's Shop" in 1989. His first critical success in a while was "Field of Dreams" in 1989, in which he played a supporting role as Moonlight Graham. He was also in the miniseries "The Betrothed" in 1989.
Later career. Lancaster's final performances included TV miniseries "The Phantom of the Opera" (1990); "" (1990) as Leon Klinghoffer based on the 1985 hijacking incident; and "Separate But Equal" (1991) with Sidney Poitier. Frequent collaborators. Lancaster appeared in a total of seventeen films produced by his agent, Harold Hecht. Eight of these were co-produced by James Hill. He also appeared in eight films produced by Hal B. Wallis and two with producer Mark Hellinger. Although Lancaster's work alongside Kirk Douglas was known as that of a successful pair of actors, Douglas, in fact, produced four films for the pair, through his production companies Bryna Productions and Joel Productions. Roland Kibbee also produced three Lancaster films, and Lancaster was also cast in two Stanley Kramer productions. Kirk Douglas. Kirk Douglas starred in seven films across the decades with Burt Lancaster: "I Walk Alone" (1948), "Gunfight at the O.K. Corral" (1957), "The Devil's Disciple" (1959), "The List of Adrian Messenger" (1963), "Seven Days in May" (1964), "Victory at Entebbe" (1976) and "Tough Guys" (1986), which fixed the notion of the pair as something of a team in the public imagination. Douglas was always billed under Lancaster in these movies but, with the exception of "I Walk Alone", in which Douglas played a villain, their roles were usually more or less the same size. Both actors arrived in Hollywood at about the same time, and first appeared together in the fourth film for each, albeit with Douglas in a supporting role. They both became actor-producers who sought out independent Hollywood careers.
John Frankenheimer. John Frankenheimer directed five films with Lancaster: "The Young Savages" (1961), "Birdman of Alcatraz" (1962), "Seven Days in May" (1964), "The Train" (1964), and "The Gypsy Moths" (1969). Other repeat collaborators. He was directed four times by Robert Aldrich, three times each by Robert Siodmak and Sydney Pollack, and twice each by Byron Haskin, Daniel Mann, John Sturges, John Huston, Richard Brooks, Alexander Mackendrick, Luchino Visconti, and Michael Winner. Roland Kibbee wrote for seven Lancaster films. Lancaster used makeup veteran Robert Schiffer in twenty credited films, hiring Schiffer on nearly all of the films he produced. Political activism. Lancaster was a vocal supporter of progressive and liberal political causes. He frequently spoke out in support of racial and other minorities. As a result, he was often a target of FBI investigations. He was named in President Richard Nixon's 1973 "Enemies List". A vocal opponent of the Vietnam War, he helped pay for the successful defense of a soldier accused of "fragging" (i.e., murdering) another soldier during war-time. In 1968, Lancaster actively supported the presidential candidacy of anti-war Senator Eugene McCarthy of Minnesota, and frequently spoke on his behalf during the Democratic primaries.
Lancaster was also active in anti-death penalty activism. He campaigned heavily for George McGovern in the 1972 United States presidential election. In 1985, Lancaster joined the fight against AIDS after fellow movie star Rock Hudson contracted the disease. Lancaster delivered Hudson's last words at the Commitment to Life fundraiser at a time when the stigma surrounding AIDS was at its height. Of his political opinions, frequent co-star Tony Curtis said: "Here's this great big aggressive guy that looks like a ding-dong athlete playing these big tough guys and he has the soul of—who were those first philosophers of equality?—Socrates, Plato. He was a Greek philosopher with a sense that everybody was equal." Actor and SAG president Ed Asner said he showed everybody in Hollywood "how to be a liberal with balls". Hollywood Ten. In 1947, Lancaster reportedly signed a statement release by the National Council of Arts, Sciences and Professions (NCASP) asking Congress to abolish the House Un-American Activities Committee (HUAC). He was also a member of the short-lived Committee for the First Amendment, formed in support of the Hollywood Ten. He was one of 26 movie stars who flew to Washington in October 1947 to protest against the HUAC hearings. The committee's "Hollywood Fights Back" broadcasts on ABC Radio Network were two 30-minute programs that took place on October 27 and November 2, 1947, during which committee members voiced their opposition to the HUAC hearings. Many members faced blacklisting and backlash due to their involvement in the committee. Lancaster was listed in anti-communist literature as a fellow traveler.
Civil rights movement. He and his second wife, Norma, hosted a fundraiser for Martin Luther King Jr. and the Student Diversity Leadership Conference (SDLC) ahead of the historic March on Washington in 1963. He attended the march, where he was one of the speakers. He flew in from France for the event, where he was shooting "The Train", and flew back again the next day, despite a reported fear of flying. On August 28, 1963, at the March on Washington Lancaster "read the speech that James Baldwin was supposed to make," because (as Malcolm X said in a speech delivered in Detroit at the King Solomon Baptist Church in late 1963) "they wouldn't let Baldwin get up there because they know Baldwin is liable to say anything." ACLU. In 1968, Lancaster was elected to serve as chairman of the Roger Baldwin Foundation, a newly formed fund-raising arm of the American Civil Liberties Union of Southern California. His co-chairs were Frank Sinatra and Irving L. Lichtenstein. In October 1968, he hosted a party at his home to raise money for the ACLU to use for the defense of the more than four hundred people arrested at the 1968 Democratic National Convention. Throughout the years, he remained an ardent supporter and a fundraiser for the organization.
While serving as a member of the five-person ACLU Foundation executive committee, he cast the key vote to retain Ramona Ripston as executive director of the Southern California affiliate, a position she would build into a powerful advocacy force in Los Angeles politics. Ripston later recalled: "There was a feeling that a woman couldn't run the ACLU foundation, nor have access to the books. The vote finally came down to two 'yes' and two 'no.' Who had the deciding vote? Burt. He had a scotch or two and finally he said, 'I think she should be executive director.' I always loved him for that." When President George H. W. Bush derided Democratic candidate Michael Dukakis as a "card-carrying member of the ACLU", Lancaster was one of the supporters featured in the organization's first television advertising campaign stating: "I'm a card-carrying member of the ACLU" and "No one agrees with every single thing they've done. But no one can disagree with the guiding principle—with liberty and justice for all.'" He also campaigned for Michael Dukakis in the 1988 United States presidential election.
Personal life. Marriages and relationships. Lancaster guarded his personal life and attempted to keep it private despite his stardom. He was married three times and had five children. His first marriage was to June Ernst, a trapeze acrobat. Ernst was the daughter of a renowned female aerialist and an accomplished acrobat herself. After they were married, he performed with her family and her until their separation in the late 1930s. When they divorced is unclear. Contemporary reports listed 1940, but subsequent biographers have suggested dates as late as 1946, delaying his marriage to his second wife. He met second wife Norma Anderson (1917–1988) when the stenographer substituted for an ill actress in a USO production for the troops in Italy. Reportedly, on seeing Lancaster in the crowd on her way to town from the airport, she turned to an officer and asked, "Who is that good-looking officer and is he married?" The officer set up a blind date between the two for that evening. They married in 1946. Norma was active in political causes with an entire room in their Bel Air home devoted to her major interest, the League of Woman Voters, crammed with printing presses and all the necessary supplies for mass mailings.
She was a life-long member of the NAACP. The couple held a fundraiser for Martin Luther King Jr. and the Southern Christian Leadership Conference ahead of the 1963 March on Washington. All five of his children were with Anderson: Bill (who became an actor and screenwriter), James, Susan, Joanna (who worked as a film producer), and Sighle (pronounced "Sheila"). It was a troubled marriage. The pair separated in 1966, and divorced in 1969. In 1966, Lancaster began a long-term relationship with hairdresser Jackie Bone, who worked on "The Professionals". The relationship was tempestuous, with Bone once smashing a wine bottle over Lancaster's head at a dinner with Sydney Pollack and Peter Falk. Reportedly, they eventually split up after her religious conversion, which Lancaster believed he could not share with her. His third marriage, to Susan Martin, lasted from September 1990 until his death in 1994. According to biographer Kate Buford in "", Lancaster was devotedly loyal to his friends and family. Old friends from his childhood remained his friends for life.
Possible affairs. Some media outlets and authors have written that Lancaster was bisexual, and had relationships with both men and women. Friends said he claimed he was romantically involved with Deborah Kerr during the filming of "From Here to Eternity" in 1953. However, Kerr stated that while there was a spark of attraction, nothing ever happened. He reportedly had an affair with Joan Blondell. In her 1980 autobiography, Shelley Winters claimed to have had a two-year affair with him, during which time he was considering separation from his wife. In his Hollywood memoirs, friend Farley Granger recalled an incident when Lancaster and he had to come to Winters' rescue one evening when she had inadvertently overdosed on alcohol and sleeping pills. She broke up with him for "cheating on her with his wife" after she heard reports of his wife's third or fourth pregnancy. Religion. Despite his Protestant background and upbringing, Lancaster identified as an atheist later in life. Later years. As Lancaster reached his 60s, he began to be affected by cardiovascular disease. In January 1980, he had complications from a routine gall bladder operation (that he barely survived). In 1983, following two minor heart attacks, he underwent an emergency quadruple coronary bypass. He continued to act, however, and to engage in public activism. In 1988, he attended a congressional hearing in Washington, DC, with former colleagues who included James Stewart and Ginger Rogers to protest against media magnate Ted Turner's plan to colorize various black-and-white films from the 1930s and 1940s. On November 30, 1990, when he was 77, a stroke left him partially paralyzed and largely unable to speak, ending his acting career.
Death. Lancaster died at his apartment in Century City, Los Angeles, after having a third heart attack at 4:50 am on October 20, 1994. His body was cremated, and his ashes were scattered under a large oak tree in Westwood Memorial Park, which is located in Westwood Village, California. A small, square ground plaque amid several others, inscribed "Burt Lancaster 1913–1994", marks the location. As he had requested, no memorial or funeral service was held for him. Legacy. The centennial of Lancaster's birth was honored at New York City's Film Society of Lincoln Center in May 2013 with the screening of 12 of the actor's best-known films, from "The Killers" to "Atlantic City". Lancaster has a star on the Hollywood Walk of Fame, at 6801 Hollywood Boulevard. Filmography and awards. Lancaster was nominated for the Oscar for Best Actor in a Leading Role in 1954 for "From Here to Eternity", in 1961 for "Elmer Gantry", in 1964 for "Birdman of Alcatraz", and in 1982 for "Atlantic City". He won the Oscar in 1961. Lancaster's leading role in Luchino Visconti's 1963 canonical "The Leopard" began a series of roles with important European art film directors that included roles in Bernardo Bertolucci's "1900" and Louis Malle's "Atlantic City" as well as Visconti's "Conversation Piece". Box office ranking. For a number of years exhibitors voted Lancaster among the most popular stars: In other media. Spanish music group Hombres G released an album named "La cagaste, Burt Lancaster" ("You messed up, Burt Lancaster") in 1986. Thomas Hart Benton painted a scene from "The Kentuckian" as part of the film's marketing. Lancaster posed for the painting, also known as "The Kentuckian".
Balts The Balts or Baltic peoples (, ) are a group of peoples inhabiting the eastern coast of the Baltic Sea who speak Baltic languages. Among the Baltic peoples are modern-day Lithuanians (including Samogitians) and Latvians (including Latgalians) — all East Balts — as well as the Old Prussians, Curonians, Sudovians, Skalvians, Yotvingians and Galindians — the West Balts — whose languages and cultures are now extinct, but made a large influence on the living branches, especially on literary Lithuanian language. The Balts are descended from a group of Proto-Indo-European tribes who settled the area between the lower Vistula and southeast shore of the Baltic Sea and upper Daugava and Dnieper rivers, and which over time became differentiated into West and East Balts. In the fifth century CE, parts of the eastern Baltic coast began to be settled by the ancestors of the Western Balts, whereas the East Balts lived in modern-day Belarus, Ukraine and Russia. In the first millennium CE, large migrations of the Balts occurred. By the 13th and 14th centuries, the East Balts shrank to the general area that the present-day Balts and Belarusians inhabit.
Baltic languages belong to the Balto-Slavic branch of the Indo-European languages. One of the features of Baltic languages is the number of conservative or archaic features retained. Etymology. Medieval German chronicler Adam of Bremen in the latter part of the 11th century AD was the first writer to use the term "Baltic" in reference to the sea of that name. Before him various ancient places names, such as Balcia, were used in reference to a supposed island in the Baltic Sea. In Germanic languages there was some form of the toponym East Sea until after about the year 1600, when maps in English began to label it as the Baltic Sea. By 1840, German nobles of the Governorate of Livonia adopted the term "Balts" to distinguish themselves from Germans of Germany. They spoke an exclusive dialect, Baltic German, which was regarded by many as the language of the Balts until 1919. In 1845, Georg Heinrich Ferdinand Nesselmann proposed a distinct language group for Latvian, Lithuanian, and Old Prussian, which he termed Baltic. The term became prevalent after Latvia and Lithuania gained independence in 1918. Up until the early 20th century, either "Latvian" or "Lithuanian" could be used to mean the entire language family.
History. Origins. The Balts or Baltic peoples, defined as speakers of one of the Baltic languages, a branch of the Indo-European language family, are descended from a group of Indo-European tribes who settled the area between the lower Vistula and southeast shore of the Baltic Sea and upper Daugava and Dnieper rivers. The Baltic languages, especially Lithuanian, retain a number of conservative or archaic features, perhaps because the areas in which they are spoken are geographically consolidated and have low rates of immigration. Some of the major authorities on Balts, such as Kazimieras Būga, Max Vasmer, Vladimir Toporov and Oleg Trubachyov, in conducting etymological studies of eastern European river names, were able to identify in certain regions names of specifically Baltic provenance, which most likely indicate where the Balts lived in prehistoric times. According to Vladimir Toporov and Oleg Trubachyov, the eastern boundary of the Balts in the prehistoric times were the upper reaches of the Volga, Moskva, and Oka rivers, while the southern border was the Seym river. This information is summarized and synthesized by Marija Gimbutas in "The Balts" (1963) to obtain a likely proto-Baltic homeland. Its borders are approximately: from a line on the Pomeranian coast eastward to include or nearly include the present-day sites of Berlin, Warsaw, Kyiv, and Kursk, northward through Moscow to the River Berzha, westward in an irregular line to the coast of the Gulf of Riga, north of Riga.
However, other scholars such as Endre Bojt (1999) reject the presumption that there ever was such a thing as a clear, single "Baltic "Urheimat"": 'The references to the Balts at various "Urheimat" locations across the centuries are often of doubtful authenticity, those concerning the Balts furthest to the West are the more trustworthy among them. (...) It is wise to group the particulars of Baltic history according to the interests that moved the pens of the authors of our sources.' Proto-history. The area of Baltic habitation shrank due to assimilation by other groups, and invasions. According to one of the theories which has gained considerable traction over the years, one of the western Baltic tribes, the Galindians, Galindae, or Goliad, migrated to the area around modern-day Moscow, Russia around the fourth century AD. Over time the Balts became differentiated into West and East Balts. In the fifth century AD parts of the eastern Baltic coast began to be settled by the ancestors of the Western Balts: Brus/Prūsa ("Old Prussians"), Sudovians/Jotvingians, Scalvians, Nadruvians, and Curonians. The East Balts, including the hypothesised Dniepr Balts, were living in modern-day Belarus, Ukraine and Russia.
Germanic peoples lived to the west of the Baltic homelands; by the first century AD, the Goths had stabilized their kingdom from the mouth of the Vistula, south to Dacia. As Roman domination collapsed in the first half of the first millennium CE in Northern and Eastern Europe, large migrations of the Balts occurred — first, the Galindae or Galindians towards the east, and later, East Balts towards the west. In the eighth century, Slavic tribes from the Volga regions appeared. By the 13th and 14th centuries, they reached the general area that the present-day Balts and Belarusians inhabit. Many other Eastern and Southern Balts either assimilated with other Balts, or Slavs in the fourth–seventh centuries and were gradually slavicized. Middle Ages. In the 12th and 13th centuries, internal struggles and invasions by Ruthenians and Poles, and later the expansion of the Teutonic Order, resulted in an almost complete annihilation of the Galindians, Curonians, and Yotvingians. Gradually, Old Prussians became Germanized or Lithuanized between the 15th and 17th centuries, especially after the Reformation in Prussia. The cultures of the Lithuanians and Latgalians/Latvians survived and became the ancestors of the populations of the modern-day countries of Latvia and Lithuania.
Old Prussian was closely related to the other extinct Western Baltic languages, Curonian, Galindian and Sudovian. It is more distantly related to the surviving Eastern Baltic languages, Lithuanian and Latvian. Compare the Prussian word "seme" ("zemē"), Latvian "zeme", the Lithuanian "žemė" ("land" in English). Culture. The Balts originally practiced Baltic religion. They were gradually Christianized as a result of the Northern Crusades of the Middle Ages. Baltic peoples such as the Latvians, Lithuanians and Old Prussians had their distinct mythologies. The Lithuanians have close historic ties to Poland, and many of them are Roman Catholic. The Latvians have close historic ties to Northern Germany and Scandinavia, and many of them are irreligious. In recent times, the Baltic religion has been revived in Baltic neopaganism. Genetics. The Balts are included in the "North European" gene cluster together with the Germanic peoples, some Slavic groups (the Poles and Northern Russians) and Baltic Finnic peoples. Saag et a. (2017) detected that the eastern Baltic in the Mesolithic was inhabited primarily by Western Hunter-Gatherers (WHGs). Their paternal haplogroups were mostly types of I2a and R1b, while their maternal haplogroups were mostly types of U5, U4 and U2. These people carried a high frequency of the derived HERC2 allele which codes for light eye color and possess an increased frequency of the derived alleles for SLC45A2 and SLC24A5, coding for lighter skin color.
Baltic hunter-gatherers still displayed a slightly larger amount of WHG ancestry than Scandinavian Hunter-Gatherers (SHGs). WHG ancestry in the Baltic was particularly high among hunter-gatherers in Latvia and Lithuania. Unlike other parts of Europe, the hunter-gatherers of the eastern Baltic do not appear to have mixed much with Early European Farmers (EEFs) arriving from Anatolia. During the Neolithic, increasing admixture from Eastern Hunter-Gatherers (EHGs) is detected. The paternal haplogroups of EHGs was mostly types of R1a, while their maternal haplogroups appears to have been almost exclusively types of U5, U4, and U2. The rise of the Corded Ware culture in the eastern Baltic in the Chalcolithic and Bronze Age is accompanied by a significant infusion of steppe ancestry and EEF ancestry into the eastern Baltic gene pool. In the aftermath of the Corded Ware expansion, local hunter-gatherer ancestry experienced a resurgence. Haplogroup N reached the eastern Baltic only in the Late Bronze Age, probably with the speakers of the Uralic languages. Modern-day Balts have a lower amount of EEF ancestry, and a higher amount of WHG ancestry, than any other population in Europe. List of Baltic peoples. Modern-day Baltic peoples
Burnt-in timecode Burnt-in timecode (often abbreviated to BITC by analogy to VITC) is a human-readable on-screen version of the timecode information for a piece of material superimposed on a video image. BITC is sometimes used in conjunction with "real" machine-readable timecode but more often used in copies of original material onto a nonbroadcast format such as VHS so that the VHS copies can be traced back to their master tape and the original timecodes easily located. Many professional VTRs can "burn" (overlay) the tape timecode onto one of their outputs. This output (which usually also displays the setup menu or on-screen display) is known as the "super out" or "monitor out". The "character" switch or menu item turns this behaviour on or off. The "character" function also displays the timecode on the preview monitors in linear editing suites. Videotapes that are recorded with timecode numbers overlaid on the video are referred to as "window dubs", named after the "window" that displays the burnt-in timecode on-screen.
When editing was done using magnetic tapes that were subject to damage from excessive wear, it was common to use a window dub as a working copy for the majority of the editing process. Editing decisions would be made using a window dub, and no specialized equipment was needed to write down an edit decision list, which would then be replicated from the high-quality masters. Timecode can also be superimposed on video using a dedicated overlay device, often called a "window dub inserter". This inputs a video signal and its separate timecode audio signal, reads the timecode, superimposes the timecode display over the video, and outputs the combined display (usually via composite), all in real time. Stand-alone timecode generators/readers often have the window dub function built in. Some consumer cameras, in particular DV cameras, can "burn" (overlay) the tape timecode onto the composite output. This output is typically semitransparent and may include other tape information. It is usually activated by turning on the "display" info in one of the camera's submenus. While not as "professional" as an overlay created by a professional VCR, it is a cheap alternative that is just as accurate.
Timecode is stored in the metadata areas of captured DV AVI files, and some software is able to "burn" (overlay) this into the video frames. For example, DVMP Pro is able to "burn" timecode or other items of DV metadata (such as date and time, iris, shutter speed, gain, white balance mode, etc.) into DV AVI files. OCR techniques can be used to read BITC in situations where other forms of timecode are not available.
Bra–ket notation Bra–ket notation, also called Dirac notation, is a notation for linear algebra and linear operators on complex vector spaces together with their dual space both in the finite-dimensional and infinite-dimensional case. It is specifically designed to ease the types of calculations that frequently come up in quantum mechanics. Its use in quantum mechanics is quite widespread. Bra–ket notation was created by Paul Dirac in his 1939 publication "A New Notation for Quantum Mechanics". The notation was introduced as an easier way to write quantum mechanical expressions. The name comes from the English word "bracket". Quantum mechanics. In quantum mechanics, bra–ket notation is used ubiquitously to denote quantum states. The notation uses angle brackets, and , and a vertical bar , to construct "bras" and "kets". A ket is of the form formula_1. Mathematically it denotes a vector, formula_2, in an abstract (complex) vector space formula_3, and physically it represents a state of some quantum system. A bra is of the form formula_4. Mathematically it denotes a linear form formula_5, i.e. a linear map that maps each vector in formula_3 to a number in the complex plane formula_7. Letting the linear functional formula_8 act on a vector formula_9 is written as formula_10.
Assume that on formula_3 there exists an inner product formula_12 with antilinear first argument, which makes formula_3 an inner product space. Then with this inner product each vector formula_14 can be identified with a corresponding linear form, by placing the vector in the anti-linear first slot of the inner product: formula_15. The correspondence between these notations is then formula_16. The linear form formula_17 is a covector to formula_18, and the set of all covectors forms a subspace of the dual vector space formula_19, to the initial vector space formula_3. The purpose of this linear form formula_17 can now be understood in terms of making projections onto the state formula_22 to find how linearly dependent two states are, etc. For the vector space formula_23, kets can be identified with column vectors, and bras with row vectors. Combinations of bras, kets, and linear operators are interpreted using matrix multiplication. If formula_23 has the standard Hermitian inner product formula_25, under this identification, the identification of kets and bras and vice versa provided by the inner product is taking the Hermitian conjugate (denoted formula_26).
It is common to suppress the vector or linear form from the bra–ket notation and only use a label inside the typography for the bra or ket. For example, the spin operator formula_27 on a two-dimensional space formula_28 of spinors has eigenvalues formula_29 with eigenspinors formula_30. In bra–ket notation, this is typically denoted as formula_31, and formula_32. As above, kets and bras with the same label are interpreted as kets and bras corresponding to each other using the inner product. In particular, when also identified with row and column vectors, kets and bras with the same label are identified with Hermitian conjugate column and row vectors. Bra–ket notation was effectively established in 1939 by Paul Dirac; it is thus also known as Dirac notation, despite the notation having a precursor in Hermann Grassmann's use of formula_33 for inner products nearly 100 years earlier. Vector spaces. Vectors vs kets. In mathematics, the term "vector" is used for an element of any vector space. In physics, however, the term "vector" tends to refer almost exclusively to quantities like displacement or velocity, which have components that relate directly to the three dimensions of space, or relativistically, to the four of spacetime. Such vectors are typically denoted with over arrows (formula_34), boldface (formula_35) or indices (formula_36).
In quantum mechanics, a quantum state is typically represented as an element of a complex Hilbert space, for example, the infinite-dimensional vector space of all possible wavefunctions (square integrable functions mapping each point of 3D space to a complex number) or some more abstract Hilbert space constructed more algebraically. To distinguish this type of vector from those described above, it is common and useful in physics to denote an element formula_37 of an abstract complex vector space as a ket formula_18, to refer to it as a "ket" rather than as a vector, and to pronounce it "ket-formula_37" or "ket-A" for . Symbols, letters, numbers, or even words—whatever serves as a convenient label—can be used as the label inside a ket, with the formula_40 making clear that the label indicates a vector in vector space. In other words, the symbol " has a recognizable mathematical meaning as to the kind of variable being represented, while just the " by itself does not. For example, is not necessarily equal to . Nevertheless, for convenience, there is usually some logical scheme behind the labels inside kets, such as the common practice of labeling energy eigenkets in quantum mechanics through a listing of their quantum numbers. At its simplest, the label inside the ket is the eigenvalue of a physical operator, such as formula_41, formula_42, formula_43, etc.
Notation. Since kets are just vectors in a Hermitian vector space, they can be manipulated using the usual rules of linear algebra. For example: Note how the last line above involves infinitely many different kets, one for each real number . Since the ket is an element of a vector space, a bra formula_45 is an element of its dual space, i.e. a bra is a linear functional which is a linear map from the vector space to the complex numbers. Thus, it is useful to think of kets and bras as being elements of different vector spaces (see below however) with both being different useful concepts. A bra formula_17 and a ket formula_47 (i.e. a functional and a vector), can be combined to an operator formula_48 of rank one with outer product Inner product and bra–ket identification on Hilbert space. The bra–ket notation is particularly useful in Hilbert spaces which have an inner product that allows Hermitian conjugation and identifying a vector with a continuous linear functional, i.e. a ket with a bra, and vice versa (see Riesz representation theorem). The inner product on Hilbert space formula_50 (with the first argument anti linear as preferred by physicists) is fully equivalent to an (anti-linear) identification between the space of kets and that of bras in the bra ket notation: for a vector ket formula_51 define a functional (i.e. bra) formula_52 by
Bras and kets as row and column vectors. In the simple case where we consider the vector space formula_23, a ket can be identified with a column vector, and a bra as a row vector. If, moreover, we use the standard Hermitian inner product on formula_23, the bra corresponding to a ket, in particular a bra and a ket with the same label are conjugate transpose. Moreover, conventions are set up in such a way that writing bras, kets, and linear operators next to each other simply imply matrix multiplication. In particular the outer product formula_56 of a column and a row vector ket and bra can be identified with matrix multiplication (column vector times row vector equals matrix). For a finite-dimensional vector space, using a fixed orthonormal basis, the inner product can be written as a matrix multiplication of a row vector with a column vector: formula_57 Based on this, the bras and kets can be defined as: formula_58 and then it is understood that a bra next to a ket implies matrix multiplication. The conjugate transpose (also called "Hermitian conjugate") of a bra is the corresponding ket and vice versa:
formula_59 because if one starts with the bra formula_60 then performs a complex conjugation, and then a matrix transpose, one ends up with the ket formula_61 Writing elements of a finite dimensional (or mutatis mutandis, countably infinite) vector space as a column vector of numbers requires picking a basis. Picking a basis is not always helpful because quantum mechanics calculations involve frequently switching between different bases (e.g. position basis, momentum basis, energy eigenbasis), and one can write something like " without committing to any particular basis. In situations involving two different important basis vectors, the basis vectors can be taken in the notation explicitly and here will be referred simply as " and "". Non-normalizable states and non-Hilbert spaces. Bra–ket notation can be used even if the vector space is not a Hilbert space. In quantum mechanics, it is common practice to write down kets which have infinite norm, i.e. non-normalizable wavefunctions. Examples include states whose wavefunctions are Dirac delta functions or infinite plane waves. These do not, technically, belong to the Hilbert space itself. However, the definition of "Hilbert space" can be broadened to accommodate these states (see the Gelfand–Naimark–Segal construction or rigged Hilbert spaces). The bra–ket notation continues to work in an analogous way in this more general context.
Banach spaces are a different generalization of Hilbert spaces. In a Banach space , the vectors may be notated by kets and the continuous linear functionals by bras. Over any vector space without a given topology, we may still notate the vectors by kets and the linear functionals by bras. In these more general contexts, the bracket does not have the meaning of an inner product, because the Riesz representation theorem does not apply. Usage in quantum mechanics. The mathematical structure of quantum mechanics is based in large part on linear algebra: Since virtually every calculation in quantum mechanics involves vectors and linear operators, it can involve, and often does involve, bra–ket notation. A few examples follow: Spinless position–space wave function. The Hilbert space of a spin-0 point particle can be represented in terms of a "position basis" , where the label extends over the set of all points in position space. These states satisfy the eigenvalue equation for the position operator: formula_62 The position states are "generalized eigenvectors", not elements of the Hilbert space itself, and do not form a countable orthonormal basis. However, as the Hilbert space is separable, it does admit a countable dense subset within the domain of definition of its wavefunctions. That is, starting from any ket in this Hilbert space, one may "define" a complex scalar function of , known as a wavefunction,
formula_63 On the left-hand side, is a function mapping any point in space to a complex number; on the right-hand side, formula_64 is a ket consisting of a superposition of kets with relative coefficients specified by that function. It is then customary to define linear operators acting on wavefunctions in terms of linear operators acting on kets, by formula_65 For instance, the momentum operator formula_66 has the following coordinate representation, formula_67 One occasionally even encounters an expression such as formula_68, though this is something of an abuse of notation. The differential operator must be understood to be an abstract operator, acting on kets, that has the effect of differentiating wavefunctions once the expression is projected onto the position basis, formula_69 even though, in the momentum basis, this operator amounts to a mere multiplication operator (by ). That is, to say, formula_70 or formula_71 Overlap of states. In quantum mechanics the expression is typically interpreted as the probability amplitude for the state to collapse into the state . Mathematically, this means the coefficient for the projection of onto . It is also described as the projection of state onto state .
Changing basis for a spin-1/2 particle. A stationary spin- particle has a two-dimensional Hilbert space. One orthonormal basis is: formula_72 where is the state with a definite value of the spin operator equal to + and is the state with a definite value of the spin operator equal to −. Since these are a basis, "any" quantum state of the particle can be expressed as a linear combination (i.e., quantum superposition) of these two states: formula_73 where and are complex numbers. A "different" basis for the same Hilbert space is: formula_74 defined in terms of rather than . Again, "any" state of the particle can be expressed as a linear combination of these two: formula_75 In vector form, you might write formula_76 depending on which basis you are using. In other words, the "coordinates" of a vector depend on the basis used. There is a mathematical relationship between formula_77, formula_78, formula_79 and formula_80; see change of basis. Pitfalls and ambiguous uses. There are some conventions and uses of notation that may be confusing or ambiguous for the non-initiated or early student.
Separation of inner product and vectors. A cause for confusion is that the notation does not separate the inner-product operation from the notation for a (bra) vector. If a (dual space) bra-vector is constructed as a linear combination of other bra-vectors (for instance when expressing it in some basis) the notation creates some ambiguity and hides mathematical details. We can compare bra–ket notation to using bold for vectors, such as formula_81, and formula_12 for the inner product. Consider the following dual space bra-vector in the basis formula_83, where formula_84 are the complex number coefficients of formula_85: formula_86 It has to be determined by convention if the complex numbers formula_84 are inside or outside of the inner product, and each convention gives different results. formula_88 formula_89 Reuse of symbols. It is common to use the same symbol for "labels" and "constants". For example, formula_90, where the symbol formula_91 is used simultaneously as the "name of the operator" formula_92, its "eigenvector" formula_93 and the associated "eigenvalue" formula_91. Sometimes the "hat" is also dropped for operators, and one can see notation such as formula_95.

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