Bipolar disorder

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Bipolar Affective Disorder
Classification & external resources

ICD-10	F31
MedlinePlus	001528
eMedicine	med/229

Bipolar disorder, once known as manic-depression, is a psychiatric diagnosis referring to a mental health condition defined by periods of extreme, often inappropriate, and sometimes unpredictable mood states.

Bipolar individuals generally experience mania, hypomania or mixed states alternating with clinical depression and euthymic or normal range of mood over varied periods of time. There are many variations of this disorder. A person with bipolar disorder generally tends to experience more extreme states of mood than other people. Moods can change quickly (many times a day) or last for months. Bipolar individuals tend to have very 'black and white' thinking, where everything in life is either a positive aspect or a negative. Mood patterns of this nature are associated with distress and disruption, and a relatively high risk of suicide. Bipolar disorder is also associated with a variety of cognitive deficits, in particular, difficulty in organizing and planning. The disorder may also skew the ability to judge others' emotion, and alter sense of awareness.^[1]

Bipolar disorder is usually treated with medications and/or therapy or counselling.

As well as being linked to disability, studies have suggested a correlation between creativity and bipolar disorder, although it is unclear what the relationship is between the two.^[2][3][4] Studies have also indicated increased striving for, and sometimes obtaining, goals and achievements more generally; in other words, many with bipolar disorder tend to be more driven, extremely goal oriented, and hard working. ^[5]

Contents 1 Aspects of bipolar disorder 1.1 The Depressive Phase 1.2 Mania 1.3 Hypomania 1.4 Mixed state 1.5 Rapid cycling 1.6 Cognition 1.7 Creativity 2 Suicide risk 3 Divorce rate 4 Diagnosis 4.1 Diagnostic criteria 4.2 Treatment lag 4.3 Children 5 Treatment 5.1 Prognosis and long-term treatment 6 Relapse 7 Research findings 7.1 Heritability or inheritance 7.2 Genetic research 8 Ongoing research 8.1 Medical imaging 8.2 New treatments 9 Etiology 10 History of bipolar disorder 11 Epidemiology 12 Mortality 13 References 14 Further reading 15 See also 16 External links

Aspects of bipolar disorder

Bipolar disorder is commonly categorised as either Bipolar Type I, where an individual experiences full-blown mania, or Bipolar Type II, in which the hypomanic "highs" do not go to the extremes of mania. The latter is much more difficult to diagnose, since the hypomanic episodes may simply appear as a period of successful high productivity and is reported less frequently than a distressing depression. Psychosis can occur, particularly in manic periods. There are also 'rapid cycling' subtypes. Because there is so much variation in the severity and nature of mood-related problems, the concept of a bipolar spectrum is often employed, which includes cyclothymia. There is no consensus as to how many 'types' of bipolar disorder exist (Akiskal and Benazzi, 2006). Many people with bipolar disorder experience severe anxiety and are very irritable (to the point of rage) when in a manic state, while others are euphoric and grandiose.

The Depressive Phase

Signs and symptoms of the depressive phase of bipolar disorder include (but in no way are limited to): persistent feelings of sadness, anxiety, guilt, anger, isolation and/or hopelessness, disturbances in sleep and appetite, fatigue and loss of interest in usually enjoyed activities, problems concentrating, loneliness, self-loathing, apathy or indifference, depersonalization, loss of interest in sexual activity, shyness or social anxiety, irritability, chronic pain (with or without a known cause), lack of motivation, and morbid/suicidal ideation.^[6]

Mania

Main article: Mania

People having a manic episode of mood can be elated, euphoric, irritated and/or suspicious. There will be an increase in physical and mental rate and quality. Increased energy and over-activity is common; speech can become racing. The need for sleep is reduced. Attention span is low and easily distracted. Unrealistic, grandiose or over optimistic ideas may be voiced or attempted. Social skills are impaired, and impractical ideas may lead to financial and relationship indiscretions.

Hypomania

Main article: Hypomania

Hypomania is generally a less destructive state than mania, and people in the hypomanic phase generally experience less of the symptoms of mania than those in a full-blown manic episode. The duration is usually also shorter than in mania. This is often a very 'artistic' state of the disorder, where there is a flight of ideas, extremely clever thinking, and an increase in energy.

Mixed state

Main article: Mixed state (psychiatry)

In the context of bipolar disorder, a mixed state is a condition during which symptoms of mania and clinical depression occur simultaneously (for example, agitation, anxiety, aggressiveness or belligerence, confusion, fatigue, impulsiveness, insomnia, irritability, morbid and/or suicidal ideation, panic, paranoia, persecutory delusions, pressured speech, racing thoughts, restlessness, and rage).^[7]

Mixed episodes can be the most volatile of the bipolar states, as moods can easily and quickly be triggered or shifted. Suicide attempts, substance abuse, and self-mutilation may occur during this state.

Rapid cycling

Rapid cycling, defined as having four or more episodes per year, is found in a significant fraction of patients with bipolar disorder. It has been associated with greater disability or a worse prognosis, due to the confusing changeability and difficulty in establishing a stable state. Rapid cycling can be induced or made worse by antidepressants.^[8]

Cognition

Numerous studies show that bipolar disorder involves certain cognitive deficits or impairments, even in states of remission.^[9] Deborah Yurgelun-Todd of McLean Hospital in Belmont, Massachusetts has argued these deficits should be included as a core feature of bipolar disorder. According to McIntyre et al. (2006), "study results now press the point that neurocognitive deficits are a primary feature of BD; they are highly prevalent and persist in the absence of overt symptomatology. Although disparate neurocognitive abnormalities have been reported, disturbances in attention, visual memory, and executive function are most consistently reported."^[10]

Creativity

Main article: Creativity and mental illness

A number of recent studies have observed a correlation between creativity and bipolar disorder,^[2][3][4] although it is unclear in which direction the cause lies, or whether both conditions are caused by some third, unknown, factor. It has been hypothesized that temperament may be one such factor.

Suicide risk

Although many people with bipolar disorder who attempt suicide never actually complete it, the annual average suicide rate in males and females with diagnosed bipolar disorder (0.4%) is 10 to more than 20 times that in the general population^[11]

Individuals with bipolar disorder tend to become suicidal, especially during mixed states such as dysphoric mania and agitated depression.^{[citation needed]} Persons suffering from Bipolar II have high rates of suicide compared to persons suffering from other mental illnesses, including Major Depression. Major Depressive episodes are part of the Bipolar II experience, and there is evidence that sufferers of this disorder spend proportionally much more of their life in the depressive phase of the illness than their counterparts with Bipolar I Disorder (Akiskal & Kessler, 2007).

Divorce rate

The divorce rate for couples where at least one spouse is bipolar is 90%^[12]. For comparison purposes, the general divorce rate is commonly held to be about half as much (around 50%), implying that this illness causes substantial additional burdens on married life.

Diagnosis

Diagnostic criteria

Main article: Current diagnostic criteria for bipolar disorder

Flux is the fundamental nature of bipolar disorder. Both within and between individuals with the illness, energy, mood, thought, sleep, and activity are among the continually changing biological markers of the disorder. The diagnostic subtypes of bipolar disorder are thus static descriptions—snapshots, perhaps—of an illness in continual change, with a great diversity of symptoms and varying degrees of severity. Individuals may stay in one subtype, or change into another, over the course of their illness. The DSM V, to be published in 2011, will likely include further and more accurate sub-typing (Akiskal and Ghaemi, 2006).

There are currently four types of bipolar illness. The Diagnostic and Statistical Manual of Mental Disorders-IV-TR (DSM-IV-TR) details four categories of bipolar disorder, Bipolar I, Bipolar II, Cyclothymia, and Bipolar Disorder NOS (Not Otherwise Specified).

For a diagnosis of Bipolar I disorder according to the DSM-IV-TR, there requires one or more manic or mixed episodes. A depressive episode is not required for the diagnosis of Bipolar I disorder but it frequently occurs.

Bipolar II, which occurs more frequently is usually characterized by at least one episode of hypomania and at least one depression.

A diagnosis of Cyclothymic Disorder requires the presence of numerous hypomanic episodes, intermingled with depressive episodes that do not meet full criteria for major depressive episodes. The main idea here is that there is a low-grade cycling of mood which appears to the observer as a personality trait, but interferes with functioning.

If an individual clearly seems to be suffering from some type of bipolar disorder but does not meet the criteria for one of the subtypes above, he or she receives a diagnosis of Bipolar Disorder NOS (Not Otherwise Specified).

Although a patient will most likely be depressed when they first seek help, it is very important to find out from the patient or the patient's family or friends if a manic or hypomaniac episode has ever been present, using careful questioning. This will prevent misdiagnosis of Depressive Disorder and avoids the use of an antidepressant which may trigger a "switch" to hypomania or mania or induce rapid cycling. Recent screening tools such as the Hypomanic Check List Questionnaire (HCL-32) have been developed to assist the quite often difficult detection of Bipolar II disorders.

Treatment lag

The behavioral manifestations of bipolar disorder are often not understood by patients nor recognized by mental health professionals, so people may suffer unnecessarily for over 10 years in some cases before receiving proper treatment.^[13]

That treatment lag is apparently not decreasing, even though there is now increased public awareness of the illness in popular magazines and health websites. Recent TV specials, for example the BBC's The Secret Life of the Manic Depressive,^[14] MTV's True Life: I'm Bipolar, talk shows, and public radio shows, and the greater willingness of public figures to discuss their own bipolar disorder, have focused on mental illnesses thereby further raising public awareness.

Despite this increased focus, individuals are still commonly misdiagnosed.^[15]

Children

Main article: Bipolar disorder in children

Children with bipolar disorder do not often meet the strict DSM-IV definition. In pediatric cases, the cycling can occur very quickly (see section above on rapid cycling).^[16]

Children with bipolar disorder tend to have rapid-cycling or mixed-cycling. Rapid cycling occurs when the cycles between depression and mania occur quickly, sometimes within the same day or the same hour. When the symptoms of both mania and depression occur simultaneously, mixed cycling occurs.

Often other psychiatric disorders are diagnosed in bipolar children. These other diagnoses may be concurrent problems, or they may be misdiagnosed as bipolar disorder. Depression, ADHD, ODD, schizophrenia, and Tourette syndrome are common comorbid conditions.

Misdiagnosis can lead to incorrect medication. Incorrect medications can trigger mania and/or suicidal ideation and attempts.

Treatment

Main article: Treatment of bipolar disorder

Currently, bipolar disorder cannot be cured, though psychiatrists and psychologists believe that it can be managed.

The emphasis of treatment is on effective management of the long-term course of the illness, which usually involves treatment of emergent symptoms. Treatment methods include pharmacological and psychotherapeutic techniques.

Prognosis and long-term treatment

A good prognosis results from good treatment which, in turn, results from an accurate diagnosis. Because bipolar disorder continues to have a high rate of both under-diagnosis and misdiagnosis, it is often difficult for individuals with the illness to receive timely and competent treatment.

Bipolar disorder is a severely disabling medical condition. However, with appropriate treatment, many individuals with bipolar disorder can live full and satisfying lives. Persons with bipolar disorder are likely to have periods of normal or near normal functioning between episodes.

Ultimately one's prognosis depends on many factors, which are, in fact, under the individual's control: the right medicines; the right dose of each; a very informed patient; a good working relationship with a competent medical doctor; a competent, supportive, and warm therapist; a supportive family or significant other; and a balanced lifestyle including a regulated stress level, regular exercise and regular sleep and wake times.

There are obviously other factors that lead to a good prognosis, as well, such as being very aware of small changes in one's energy, mood, sleep and eating behaviors, as well as having a plan in conjunction with one's doctor for how to manage subtle changes that might indicate the beginning of a mood swing. Some people find that keeping a log of their moods can assist them in predicting changes.

The goals of long-term optimal treatment are to help the individual achieve the highest level of functioning while avoiding relapse.

Relapse

Even when on medication, some people may still experience weaker episodes, or have a complete manic or depressive episode. In fact, a recent study found bipolar disorder to be "characterized by a low rate of recovery, a high rate of recurrence, and poor interepisodic functioning." Worse, the study confirmed the seriousness of the disorder as "the standardized all-cause mortality ratio among patients with BD is increased approximately 2-fold." Bipolar disorder is currently regarded "as possibly the most costly category of mental disorders in the United States."^[17]

The following behaviors can lead to depressive or manic relapse:

• Discontinuing or lowering one's dose of medication, without consulting one's physician.
• Being under- or over-medicated. Generally, taking a lower dosage of a mood stabilizer can lead to relapse into mania. Taking a lower dosage of an antidepressant, may cause the patient to relapse into depression, while higher doses can cause destabilization into mixed-states or mania.
• Taking hard drugs—recreationally or not—such as cocaine, alcohol, amphetamines, or opiates. These can cause the condition to worsen.
• An inconsistent sleep schedule can destabilize the illness. Too much sleep (possibly caused by medication) can lead to depression, while too little sleep can lead to mixed states or mania.
• Caffeine can cause destabilization of mood toward irritability, dysphoria, and mania. Anecdotal evidence seems to suggest that lower dosages of caffeine can have effects ranging from anti-depressant to mania-inducing.
• Inadequate stress management and poor lifestyle choices. If unmedicated, excessive stress can cause the individual to relapse. Medication raises the stress threshold somewhat, but too much stress still causes relapse.

Relapse can be managed by the sufferer with the help of a close friend, based on the occurrence of idiosyncratic prodromal events^[18] That is, by noticing which moods, activities / behaviours or thinking process / thought content typically occur at the outset of their episodes. They can then take planned steps to slow or reverse the onset of illness, or take action to prevent the episode causing damage to important aspects of their life.^[19]

Research findings

Heritability or inheritance

The disorder runs in families.^[20] More than two-thirds of people with bipolar disorder have at least one close relative with the disorder or with unipolar major depression, indicating that the disease has a genetic component.

Studies seeking to identify the genetic basis of bipolar disorder indicate that susceptibility stems from multiple genes. Scientists are continuing their search for these genes, using advanced genetic analytic methods and large samples of families affected by the illness. The researchers are hopeful that identification of susceptibility genes for bipolar disorder, and the brain proteins they code for, will make it possible to develop better treatments and preventive interventions targeted at the underlying illness process.

Genetic research

Bipolar disorder is considered to be a result of complex interactions between genes and environment.

The monozygotic concordance rate for the disorder is 70%. This means that if a person has the disorder, an identical twin has a 70% likelihood of having the disorder as well. Dizygotic twins have a 23% concordance rate. These concordance rates are not universally replicated in the literature; recent studies have shown rates of around 40% for monozygotic and <10% for dizygotic twins (see Kieseppa, 2004^[21] and Cardno, 1999^[22]).

In 2003, a group of American and Canadian researchers published a paper that used gene linkage techniques to identify a mutation in the GRK3 gene as a possible cause of up to 10% of cases of bipolar disorder. This gene is associated with a kinase enzyme called G protein receptor kinase 3, which appears to be involved in dopamine metabolism, and may provide a possible target for new drugs for bipolar disorder.^[23]

Ongoing research

The following studies are ongoing, and are recruiting volunteers:

The Maudsley Bipolar Twin Study, based at the Institute of Psychiatry in London is conducting research about the genetic basis of bipolar disorder using twin methodology. Currently recruiting volunteers: identical and non-identical twins pairs, where either one or both twins has a diagnosis of bipolar I or II.

The MRC eMonitoring Project, another research study based at the Institute of Psychiatry and Newcastle Universities, is conducting novel research on electronic monitoring methodologies (electronic mood diaries and actigraphy) for tracking bipolar symptom fluctuations in Bipolar individuals who are interested in self-managing their condition.

Medical imaging

Researchers are using advanced brain imaging techniques to examine brain function and structure in people with bipolar disorder, particularly using the functional MRI and positron emission tomography. An important area of neuroimaging research focuses on identifying and characterizing networks of interconnected nerve cells in the brain, interactions among which form the basis for normal and abnormal behaviors. Researchers hypothesize that abnormalities in the structure and/or function of certain brain circuits could underlie bipolar and other mood disorders, and studies have found anatomical differences in areas such as the prefrontal cortex^[24] and hippocampus.

Better understanding of the neural circuits involved in regulating mood states, and genetic factors such as the cadherin gene FAT linked to bipolar disorder,^[25] may influence the development of new and better treatments, and may ultimately aid in early diagnosis and even a cure

New treatments

In late 2003, researchers at McLean Hospital found tentative evidence of improvements in mood during echo-planar magnetic resonance spectroscopic imaging (EP-MRSI), and attempts are being made to develop this into a form which can be evaluated as a possible treatment.^[26][27]

NIMH has initiated a large-scale study at 20 sites across the United States to determine the most effective treatment strategies for people with bipolar disorder. This study, the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD), will follow patients and document their treatment outcome for 5-8 years. For more information, visit the Clinical Trials page of the NIMH Web site.^[28]

Transcranial magnetic stimulation is another fairly new technique being studied.

Pharmaceutical research is extensive and ongoing, as seen at clinicaltrials.gov.

Etiology

According to the U.S. government's National Institute of Mental Health (NIMH), "There is no single cause for bipolar disorder—rather, many factors act together to produce the illness." "Because bipolar disorder tends to run in families, researchers have been searching for specific genes passed down through generations that may increase a person's chance of developing the illness." "In addition, findings from gene research suggest that bipolar disorder, like other mental illnesses, does not occur because of a single gene.".^[29]

It is well established that bipolar disorder is a genetically influenced condition which can respond very well to medication (Johnson & Leahy, 2004; Miklowitz & Goldstein, 1997; Frank, 2005). (See treatment of bipolar disorder for a more detailed discussion of treatment.)

Psychological factors also play a strong role in both the psychopathology of the disorder and the psychotherapeutic factors aimed at alleviating core symptoms, recognizing episode triggers, reducing negative expressed emotion in relationships, recognizing prodromal symptoms before full-blown recurrence, and, practising the factors that lead to maintenance of remission (Lam et al, 1999; Johnson & Leahy, 2004; Basco & Rush, 2005; Miklowitz & Goldstein, 1997; Frank, 2005). Modern evidence based psychotherapies designed specifically for bipolar disorder when used in combination with standard medication treatment increase the time the individual stays well significantly longer than medications alone (Frank, 2005). These psychotherapies are interpersonal and social rhythm therapy for bipolar disorder, family focused therapy for bipolar disorder, psychoeducation, cognitive therapy for bipolar disorder, and prodrome detection. All except psychoeducation and prodrome detection are available as books.

Abnormalities in brain function have been related to feelings of anxiety and lower stress resilience. When faced with a very stressful, negative major life event, such as a failure in an important area, an individual may have his first major depression. Conversely, when an individual accomplishes a major achievement he may experience his first hypomanic or manic episode. Individuals with bipolar disorder tend to experience episode triggers involving either interpersonal or achievement-related life events. An example of interpersonal-life events include falling in love or, conversely, the death of a close friend. Achievement-related life events include acceptance into an elite graduate school or by contrast, being fired from work (Miklowitz & Goldstein, 1997). Childbirth can also trigger a postpartum psychosis for bipolar women, which can lead in the worse cases to infanticide.

The "kindling" theory^[30] asserts that people who are genetically predisposed toward bipolar disorder can experience a series of stressful events, each of which lowers the threshold at which mood changes occur. Eventually, a mood episode can start (and becomes recurrent) by itself. Not all individuals experience subsequent mood episodes in the absence of positive or negative life events, however.

Individuals with late-adolescent/early adult onset of the disorder will very likely have experienced childhood anxiety and depression. Some argue that childhood-onset bipolar disorder should be treated early.

A family history of bipolar spectrum disorders can impart a genetic predisposition towards developing a bipolar spectrum disorder.^[31] Since bipolar disorders are polygenic (involving many genes), there are apt to be many unipolar and bipolar disordered individuals in the same family pedigree. This is very often the case (Barondes, 1998). Anxiety disorders, clinical depression, eating disorders, premenstrual dysphoric disorder, postpartum depression, postpartum psychosis and/or schizophrenia may be part of the patient's family history and reflects a term called "genetic loading".

Bipolar disorder is not either environmental or physiological, it is multifactorial; that is, many genes and environmental factors conspire to create the disorder (Johnson & Leahy, 2004).

Since bipolar disorder is so heterogeneous, it is likely that people experience different pathways towards the illness (Miklowitz & Goldstein, 1997).

Recent research done in Japan indicates a hypothesis of dysfunctional mitochondria in the brain (Stork & Renshaw, 2005)

History of bipolar disorder

Main article: History of bipolar disorder

Varying moods and energy levels have been a part of the human experience since time immemorial. The words "depression" (previously "melancholia") and "mania" have their etymologies in Ancient Greek. The word melancholia is derived from ‘melas’, meaning black, and ‘chole’, meaning bile, indicative of the term’s origins in pre-Hippocratic humoral theories. Within the humoral theories, mania was viewed as arising from an excess of yellow bile, or a mixture of black and yellow bile. The linguistic origins of mania, however, are not so clear-cut. Several etymologies are proposed by the Roman physician Caelius Aurelianus, including the Greek word ‘ania’, meaning to produce great mental anguish, and ‘manos’, meaning relaxed or loose, which would contextually approximate to an excessive relaxing of the mind or soul (Angst and Marneros 2001). There are at least five other candidates, and part of the confusion surrounding the exact etymology of the word mania is its varied usage in the pre-Hippocratic poetry and mythologies (Angst and Marneros 2001).

The idea of a relationship between mania and melancholia can be traced back to at least the 2nd century AD. Soranus of Ephesus (98-177 AD) described mania and melancholia as distinct diseases with separate etiologies; however, he acknowledged that “many others consider melancholia a form of the disease of mania” (Cited in Mondimore 2005 p.49).

A clear understanding of bipolar disorder as a mental illness was recognized by early Chinese authors. The encyclopedist Gao Lian (c. 1583) describes the malady in his Eight Treatises on the Nurturing of Life (Ts'un-sheng pa-chien).

The earliest written descriptions of a relationship between mania and melancholia are attributed to Aretaeus of Cappadocia. Aretaeus was an eclectic medical philosopher who lived in Alexandria somewhere between 30 and 150 AD (Roccatagliata 1986; Akiskal 1996). Aretaeus is recognized as having authored most of the surviving texts referring to a unified concept of manic-depressive illness, viewing both melancholia and mania as having a common origin in ‘black bile’ (Akiskal 1996; Marneros 2001).

The contemporary psychiatric conceptualisation of manic-depressive illness is typically traced back to the 1850s. Marneros (2001) describes the concepts emerging out of this period as the “rebirth of bipolarity in the modern era”. On January 31, 1854, Jules Baillarger described to the French Imperial Academy of Medicine a biphasic mental illness causing recurrent oscillations between mania and depression. Two weeks later, on February 14, 1854, Jean-Pierre Falret presented a description to the Academy on what was essentially the same disorder. This illness was designated folie circulaire (‘circular insanity’) by Falret, and folie à double forme (‘dual-form insanity’) by Baillarger (Sedler 1983).

Emil Kraepelin (1856-1926), a German psychiatrist considered by many (including Hagop Akiskal M.D.) to be the father of the modern conceptualization of bipolar disorder, categorized and studied the natural course of untreated bipolar patients long before mood stabilizers were discovered. Describing these patients in 1902, he coined the term "manic depressive psychosis." He noted in his patient observations that intervals of acute illness, manic or depressive, were generally punctuated by relatively symptom-free intervals in which the patient was able to function normally.

After World War II, Dr. John Cade, an Australian psychiatrist, was investigating the effects of various compounds on veteran patients with manic depressive psychosis. In 1949, Cade discovered that lithium carbonate could be used as a successful treatment of manic depressive psychosis. ^[32] Because there was a fear that table salt substitutes could lead to toxicity or death, Cade's findings did not immediately lead to treatments. In the 1950s, U.S. hospitals began experimenting with lithium on their patients. By the mid-'60s, reports started appearing in the medical literature regarding lithium's effectiveness. The U.S. Food and Drug Administration did not approve of lithium's use until 1970.^[33]

The term "manic-depressive illness" first appeared in 1958. The current nosology, bipolar disorder, became popular only recently, and some individuals prefer the older term because it provides a better description of a continually changing multi-dimensional illness.

Epidemiology

Clinical depression and bipolar disorder are currently classified as separate illnesses. Some researchers increasingly view them as part of an overlapping spectrum that also includes anxiety and psychosis.

According to Hagop Akiskal, M.D., at the one end of the spectrum is bipolar type schizoaffective disorder, and at the other end is unipolar depression (recurrent or not recurrent), with the anxiety disorders present across the spectrum. Also included in this view is premenstrual dysphoric disorder, postpartum depression, and postpartum psychosis. This view helps to explain why many people who have the illness do not have first-degree relatives with clear-cut "bipolar disorder", but who have family members with a history of these other disorders.

In a 2003 study, Hagop Akiskal M.D. and Lew Judd M.D. re-examined data from the landmark Epidemiologic Catchment Area study from two decades before.^[34] The original study found that 0.8 percent of the population surveyed had experienced a manic episode at least once (the diagnostic threshold for bipolar I) and 0.5 a hypomanic episode (the diagnostic threshold for bipolar II).

By tabulating survey responses to include sub-threshold diagnostic criteria, such as one or two symptoms over a short time-period, the authors arrived at an additional 5.1 percent of the population, adding up to a total of 6.4 percent of the entire population who can be thought of as having a bipolar spectrum disorder. This and similar recent studies have been interpreted by some prominent bipolar disorders researchers as evidence for a much higher prevalence of bipolar disorders in the general population than previously thought.

However these re-analyses should be interpreted cautiously because of substantive as well as methodological study limitations. Indeed, prevalence studies of bipolar disorder are carried out by lay interviewers (that is, not by expert clinicians/psychiatrists who are more costly to employ) who follow fully structured/fixed interview schemes; responses to single items from such interviews may suffer limited validity.

Furthermore, a well-known statistical problem arises when ascertaining disorders and conditions with a relatively low population prevalence or base-rate, such as bipolar disorder: even assuming that lay interviews diagnoses are highly accurate in terms of sensitivity and specificity and their corresponding area under the ROC curve (that is, AUC, or area under the receiver operating characteristic curve), a condition with a relatively low prevalence or base-rate is bound to yield high false positive rates, which exceed false negative rates; in such a circumstance a limited positive predictive value, PPV, yields high false positive rates even in presence of a specificity which is very close to 100% (Baldessarini, Finklestein, Arana, 1983).^[35] To simplify, it can be said that a very small error applied over a very large number of individuals (that is, those who are *not affected* by the condition in the general population during their lifetime; for example, over 95%) produces a relevant, non-negligible number of subjects who are incorrectly classified as having the disorder or any other condition which is the object of a survey study: these subjects are the so-called false positives; such reasoning applies to the 'false positive' but not the 'false negative' problem where we have an error applied over a relatively very small number of individuals to begin with (that is, those who are *affected* by the condition in the general population; for example, less than 5%). Hence, a very high percentage of subjects who seem to have a history of bipolar disorder at the interview are false positives for such a medical condition and apparently never suffered a fully clinical syndrome (that is, bipolar disorder type I): the population prevalence of bipolar disorder type I, which includes at least a lifetime manic episode, continues to be estimated at 1% (Soldani, Sullivan, Pedersen, 2005).^[36]

A different but related problem in evaluating the public health significance of psychiatric conditions has been highlighted by Robert Spitzer of Columbia University: fulfillment of diagnostic criteria and the resulting diagnosis do not necessarily imply need for treatment (Spitzer, 1998).^[37] As a consequence, subjects who experience bipolar symptoms but not a full-blown, impairing bipolar syndrome should not be automatically considered as patients in need of treatment.

Recent studies have indicated that at least 50% of adult sufferers report manifestation of symptoms before the age of 17. Moreover, there is a growing consensus that bipolar disorder originates in childhood. In young children the illness is now referred to as pediatric bipolar disorder. Today about 0.5% of children under 18 are believed to have the condition. For children, the main concern is that bipolar disorder needs to be diagnosed correctly and treated properly because it can look like unipolar depression, ADHD, or conduct disorder. If a child with bipolar disorder is misdiagnosed and treated with antidepressants or stimulants, the child may become violent, suicidal, homicidal, or otherwise severely destabilized. Young children, adolescents and adults each express the illness differently according to child and adolescent bipolar disorders expert Demitri Papolos M.D. and the Child and Adolescent Bipolar Foundation. There is, however, controversy about this last point^[38]

Bipolar disorder manifests in late life as well. Some individuals with "hyperthymic" temperament (or "hypomanic" personality style) who experience depression in later life appear to have a form of bipolar disorder. Much more needs to be elucidated about late-life bipolar disorder.

Approximately 50% of children in the U.S. child welfare system who have reactive attachment disorder also have comorbid Bipolar I disorder according to research by John Alston, MD.

Mortality

"Mortality studies have documented an increase in all-cause mortality in patients with BD. A newly established and rapidly growing database indicates that mortality due to chronic medical disorders (eg, cardiovascular disease) is the single largest cause of premature and excess deaths in BD. The standardized mortality ratio from suicide in BD is estimated to be approximately 18 to 25, further emphasizing the lethality of the disorder.".^[39]

References

Further reading

Contemporary first-person accounts on this subject include

• Jamison, Kay Redfield. 1995. An Unquiet Mind: A Memoir of Moods and Madness. New York: Knopf. ISBN 0-330-34651-2.
• Simon, Lizzie. 2002. Detour: My Bipolar Road Trip in 4-D. New York: Simon and Schuster. ISBN 0-7434-4659-3.
• Behrman, Andy. 2002. Electroboy: A Memoir of Mania. New York: Random House, 2002. ISBN 0-375-50358-7.

For a practical guide to living with bipolar disorder from the perspective of the sufferer, see

• Kelly, Madeleine Bipolar and the Art of Roller-coaster Riding. Strathbogie: Two Trees Media 2005 ISBN 0-646-44939-7

For a critique of genetic explanations of bipolar disorder, see

• Joseph, J. 2006. The Missing Gene: Psychiatry, Heredity, and the Fruitless Search for Genes. New York: Algora.

For readings regarding bipolar disorder in children, see:

• Raeburn, Paul. 2004. Acquainted with the Night: A Parent's Quest to Understand Depression and Bipolar Disorder in His Children.
• Earley, Pete. Crazy. 2006. New York: G. P. Putnam's Sons. ISBN 0-399-15313-6. A father's account of his son's bipolar disorder.
• About Pediatric Bipolar Disorder: www.bpkids.org/site/PageServer?pagename=lrn_about
• The Child and Adolescent Bipolar Foundation: www.bpkids.org
• Time Magazine checklist for childhood/adolescent bipolarity: www.time.com/time/covers/1101020819/worksheet/
• A Model IEP for a bipolar child's medication that works correctly: http://www.bipolarchild.com/iep.html

Classic works on this subject include

• Kraepelin, Emil. 1921. Manic-depressive Insanity and Paranoia ISBN 0-405-07441-7 (English translation of the original German from the earlier eighth edition of Kraepelin's textbook - now outdated, but a work of major historical importance).
• Manic-Depressive Illness by Frederick K. Goodwin and Kay Redfield Jamison. ISBN 0-19-503934-3 (The standard, very lengthy, medical reference on bipolar disorder.)
• Touched With Fire: Manic-Depressive Illness and the Artistic Temperament by Kay Redfield Jamison (The Free Press: Macmillian, Inc., New York, 1993) 1996 reprint: ISBN 0-684-83183-X
• Mind Over Mood: Cognitive Treatment Therapy Manual for Clients by Christine Padesky, Dennis Greenberger. ISBN 0-89862-128-3

See also

• Borderline Personality Disorder
• Mood (psychology)
• Emotion
• List of people believed to have been affected by bipolar disorder
• List of songs about bipolar disorder
• Bipolar spectrum
• Seasonal affective disorder
• Oppositional Defiance Disorder
• Emotional dysregulation
• Creativity and bipolar disorder
• Bipolar disorders research

External links

Bipolar Disorder at the Open Directory Project (suggest site)