So what causes you to be Bipolar?
The causes of bipolar disorder likely vary between individuals. 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, the (probandwise) concordance rates in modern studies have been consistently put at around 40% in monozygotic twins (same genes), compared to 0 to 10% in dizygotic twins. A combination of bipolar I, II and cyclothymia
produced concordance rates of 42% vs 11%, with a relatively lower ratio
for bipolar II that likely reflects heterogeneity. The overall heritability of the bipolar spectrum has been put at 0.71. There is overlap with unipolar depression
and if this is also counted in the co-twin the concordance with bipolar
disorder rises to 67% in monozigotic twins and 19% in dizigotic. The relatively low concordance between dizygotic 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 Genetic studies have suggested many chromosomal regions and candidate genes appearing to relate to the development of bipolar disorder, but the results are not consistent and often not replicated.
Although the first genetic linkage finding for mania was in 1969, the linkage studies have been inconsistent. Meta-analyses of linkage studies detected either no significant genome-wide findings or, using a different methodology, only two genome-wide significant peaks, on chromosome 6q and on 8q21.[citation needed] Genome-wide association studies neither brought a consistent focus — each has identified new loci.
Findings point strongly to heterogeneity, with different genes being implicated in different families. A review seeking to identify the more consistent findings suggested several genes related to serotonin (SLC6A4 and TPH2), dopamine (DRD4 and SLC6A3), glutamate (DAOA and DTNBP1), and cell growth and/or maintenance pathways (NRG1, DISC1 and BDNF), although noting a high risk of false positives in the published literature. It was also suggested that individual genes are likely to have only a small effect and to be involved in some aspect related to the disorder (and a broad range of "normal" human behavior) rather than the disorder per se.
Advanced paternal age has been linked to a somewhat increased chance of bipolar disorder in offspring, consistent with a hypothesis of increased new genetic mutations.
Physiological Abnormalities in the structure and/or function of certain brain circuits could underlie bipolar. Two meta-analyses of MRI studies in bipolar disorder report a increase in the volume of the lateral ventricles, globus pallidus and increase in the rates of deep white matter hyperintensities.
The "kindling" theory 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 become recurrent) by itself. There is evidence of hypothalamic-pituitary-adrenal axis (HPA axis) abnormalities in bipolar disorder due to stress.
Other brain components which have been proposed to play a role are the mitochondria, and a sodium ATPase pump, causing cyclical periods of poor neuron firing (depression) and hypersensitive neuron firing (mania). This may only apply for type one, but type two apparently results from a large confluence of factors. Circadian rhythms and melatonin activity also seem to be altered.
Environmental Evidence suggests that environmental factors play a significant role in the development and course of bipolar disorder, and that individual psychosocial variables may interact with genetic dispositions. There is fairly consistent evidence from prospective studies that recent life events and interpersonal relationships contribute to the likelihood of onsets and recurrences of bipolar mood episodes, as they do for onsets and recurrences of unipolar depression.There have been repeated findings that between a third and a half of adults diagnosed with bipolar disorder report traumatic/abusive experiences in childhood, which is associated on average with earlier onset, a worse course, and more co-occurring disorders such as PTSD. The total number of reported stressful events in childhood is higher in those with an adult diagnosis of bipolar spectrum disorder compared to those without, particularly events stemming from a harsh environment rather than from the child's own behavior. Early experiences of adversity and conflict are likely to make subsequent developmental challenges in adolescence more difficult, and are likely a potentiating factor in those at risk of developing bipolar disorder. Many gifted and talented children (and adults) are mis-diagnosed by psychologists, psychiatrists, pediatricians, and other health care professionals. One of the most common mis-diagnoses is Bi-Polar Disorder. This type of mis-diagnoses stems from an ignorance among professionals about the social and emotional characteristics of gifted children which are then mistakenly assumed by these professionals to be signs of pathology.
Diagnosis Diagnosis is based on the self-reported experiences of an individual as well as abnormalities in behavior reported by family members, friends or co-workers, followed by secondary signs observed by a psychiatrist, nurse, social worker, clinical psychologist or other clinician in a clinical assessment. There are lists of criteria for someone to be so diagnosed. These depend on both the presence and duration of certain signs and symptoms. 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 Diagnostic and Statistical Manual of Mental Disorders, the current version being DSM-IV-TR, and the World Health Organization's International Statistical Classification of Diseases and Related Health Problems, currently the ICD-10. The latter criteria are typically used in Europe and other regions while the DSM criteria are used in the USA and other regions, as well as prevailing in research studies.
An initial assessment may include a physical exam by a physician. Although there are no biological tests which confirm bipolar disorder, tests may be carried out to exclude medical illnesses such as hypo- or hyperthyroidism, metabolic disturbance, a systemic infection or chronic disease, and syphilis or HIV infection. An EEG may be used to exclude epilepsy, and a CT scan of the head to exclude brain lesions. Investigations are not generally repeated for relapse unless there is a specific medical indication.
Several rating scales for the screening and evaluation of BD exist, such as the Bipolar spectrum diagnostic scale. The use of evaluation scales can not substitute a full clinical interview but they serve to systematize the recollection of symptoms.On the other hand instruments for the screening of BD have low sensitivity and limited diagnostic validity.
Criteria and subtypes There is no clear consensus as to how many types of bipolar disorder exist.In DSM-IV-TR and ICD-10, bipolar disorder is conceptualized as a spectrum of disorders occurring on a continuum. The DSM-IV-TR lists three specific subtypes and one for non-specified:
Bipolar I disorderOne or more manic episodes. Subcategories specify whether there has been more than one episode, and the type of the most recent episode. A depressive or hypomanic episode is not required for diagnosis, but it frequently occurs.Bipolar II disorderNo manic episodes, but one or more hypomanic episodes and one or more major depressive episode. However, a bipolar II diagnosis is not a guarantee that they will not eventually suffer from such an episode in the future.[citation needed] Hypomanic episodes do not go to the full extremes of mania (i.e., do not usually cause severe social or occupational impairment, and are without psychosis), and this can make bipolar II 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, crippling depression.CyclothymiaA history of hypomanic episodes with periods of depression that do not meet criteria for major depressive episodes.There is a low-grade cycling of mood which appears to the observer as a personality trait, and interferes with functioning.Bipolar Disorder NOS (Not Otherwise Specified)This is a catchall category, diagnosed when the disorder does not fall within a specific subtype. Bipolar NOS can still significantly impair and adversely affect the quality of life of the patient. The bipolar I and II categories have specifiers that indicate the presentation and course of the disorder. For example, the "with full interepisode recovery" specifier applies if there was full remission between the two most recent episodes.
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 of the above subtypes. It is defined as having four or more episodes per year and is found in a significant fraction of individuals with bipolar disorder. The definition of rapid cycling most frequently cited in the literature (including the DSM) is that of Dunner and Fieve: at least four major depressive, manic, hypomanic or mixed episodes are required to have occurred during a 12-month period. Ultra-rapid (days) or ultra-ultra rapid or ultradian (within a day) cycling have also been described.
Differential diagnosis There are several other mental disorders which may involve similar symptoms to bipolar disorder. These include schizophrenia,[56] schizoaffective disorder, drug intoxication, brief drug-induced psychosis, schizophreniform disorder and borderline personality disorder. Both borderline personality and bipolar disorder can involve what are referred to as "mood swings". In bipolar disorder, the term refers to the cyclic episodes of elevated and depressed mood which generally last weeks or months. The term in borderline personality refers to the marked lability and reactivity of mood, known as emotional dysregulation, due to response to external psychosocial and intrapsychic stressors; these may arise or subside suddenly and dramatically and last for seconds, minutes, hours or days. A bipolar depression is generally more pervasive with sleep, appetite disturbance and nonreactive mood, whereas the mood in dysthymia of borderline personality remains markedly reactive and sleep disturbance not acute. Some hold that borderline personality disorder represents a subthreshold form of mood disorder while others maintain the distinctness, though noting they often coexist.
Challenges The experiences and behaviors involved in bipolar disorder are often not understood by individuals or recognized by mental health professionals, so diagnosis may sometimes be delayed for over 10 years. The treatment lag is apparently not decreasing, even though there is increased public awareness of the condition.
Individuals are commonly misdiagnosed. An individual may appear simply depressed when they are seen by a health professional. This can result in misdiagnosis of Major Depressive Disorder. However, there is also a long-standing issue in the research literature as to whether a categorical classificatory divide between unipolar and bipolar depression is actually valid, or whether it is more accurate to talk of a continuum involving dimensions of depression and mania.
It has been noted that the bipolar disorder diagnosis is officially characterised in historical terms such that, technically, anyone with a history of (hypo)mania and depression has bipolar disorder whatever their current or future functioning and vulnerability. This has been described as "an ethical and methodological issue", as it means no one can be considered as being recovered (only "in remission") from bipolar disorder according to the official criteria. This is considered especially problematic given that brief hypomanic episodes are widespread among people generally and not necessarily associated with dysfunction.
Flux is the fundamental nature of bipolar disorder. Individuals with the illness have continual changes in energy, mood, thought, sleep, and activity. The diagnostic subtypes of bipolar disorder are thus static descriptions—snapshots, perhaps—of an illness in continual flux, 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 2013, will likely include further and more accurate sub-typing (Akiskal and Ghaemi, 2006).
The diagnosis of bipolar disorder can be complicated by coexisting psychiatric conditions such as obsessive-compulsive disorder, social phobia, panic disorder, or attention-deficit/hyperactivity disorder. Substance abuse may predate the appearance of bipolar symptoms, further complicating the diagnosis. A careful longitudinal analysis of symptoms and episodes, enriched if possible by discussions with friends and family members, is crucial to establishing a treatment plan where these comorbidities exist.
Genetic Genetic studies have suggested many chromosomal regions and candidate genes appearing to relate to the development of bipolar disorder, but the results are not consistent and often not replicated.
Although the first genetic linkage finding for mania was in 1969, the linkage studies have been inconsistent. Meta-analyses of linkage studies detected either no significant genome-wide findings or, using a different methodology, only two genome-wide significant peaks, on chromosome 6q and on 8q21.[citation needed] Genome-wide association studies neither brought a consistent focus — each has identified new loci.
Findings point strongly to heterogeneity, with different genes being implicated in different families. A review seeking to identify the more consistent findings suggested several genes related to serotonin (SLC6A4 and TPH2), dopamine (DRD4 and SLC6A3), glutamate (DAOA and DTNBP1), and cell growth and/or maintenance pathways (NRG1, DISC1 and BDNF), although noting a high risk of false positives in the published literature. It was also suggested that individual genes are likely to have only a small effect and to be involved in some aspect related to the disorder (and a broad range of "normal" human behavior) rather than the disorder per se.
Advanced paternal age has been linked to a somewhat increased chance of bipolar disorder in offspring, consistent with a hypothesis of increased new genetic mutations.
Physiological Abnormalities in the structure and/or function of certain brain circuits could underlie bipolar. Two meta-analyses of MRI studies in bipolar disorder report a increase in the volume of the lateral ventricles, globus pallidus and increase in the rates of deep white matter hyperintensities.
The "kindling" theory 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 become recurrent) by itself. There is evidence of hypothalamic-pituitary-adrenal axis (HPA axis) abnormalities in bipolar disorder due to stress.
Other brain components which have been proposed to play a role are the mitochondria, and a sodium ATPase pump, causing cyclical periods of poor neuron firing (depression) and hypersensitive neuron firing (mania). This may only apply for type one, but type two apparently results from a large confluence of factors. Circadian rhythms and melatonin activity also seem to be altered.
Environmental Evidence suggests that environmental factors play a significant role in the development and course of bipolar disorder, and that individual psychosocial variables may interact with genetic dispositions. There is fairly consistent evidence from prospective studies that recent life events and interpersonal relationships contribute to the likelihood of onsets and recurrences of bipolar mood episodes, as they do for onsets and recurrences of unipolar depression.There have been repeated findings that between a third and a half of adults diagnosed with bipolar disorder report traumatic/abusive experiences in childhood, which is associated on average with earlier onset, a worse course, and more co-occurring disorders such as PTSD. The total number of reported stressful events in childhood is higher in those with an adult diagnosis of bipolar spectrum disorder compared to those without, particularly events stemming from a harsh environment rather than from the child's own behavior. Early experiences of adversity and conflict are likely to make subsequent developmental challenges in adolescence more difficult, and are likely a potentiating factor in those at risk of developing bipolar disorder. Many gifted and talented children (and adults) are mis-diagnosed by psychologists, psychiatrists, pediatricians, and other health care professionals. One of the most common mis-diagnoses is Bi-Polar Disorder. This type of mis-diagnoses stems from an ignorance among professionals about the social and emotional characteristics of gifted children which are then mistakenly assumed by these professionals to be signs of pathology.
Diagnosis Diagnosis is based on the self-reported experiences of an individual as well as abnormalities in behavior reported by family members, friends or co-workers, followed by secondary signs observed by a psychiatrist, nurse, social worker, clinical psychologist or other clinician in a clinical assessment. There are lists of criteria for someone to be so diagnosed. These depend on both the presence and duration of certain signs and symptoms. 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 Diagnostic and Statistical Manual of Mental Disorders, the current version being DSM-IV-TR, and the World Health Organization's International Statistical Classification of Diseases and Related Health Problems, currently the ICD-10. The latter criteria are typically used in Europe and other regions while the DSM criteria are used in the USA and other regions, as well as prevailing in research studies.
An initial assessment may include a physical exam by a physician. Although there are no biological tests which confirm bipolar disorder, tests may be carried out to exclude medical illnesses such as hypo- or hyperthyroidism, metabolic disturbance, a systemic infection or chronic disease, and syphilis or HIV infection. An EEG may be used to exclude epilepsy, and a CT scan of the head to exclude brain lesions. Investigations are not generally repeated for relapse unless there is a specific medical indication.
Several rating scales for the screening and evaluation of BD exist, such as the Bipolar spectrum diagnostic scale. The use of evaluation scales can not substitute a full clinical interview but they serve to systematize the recollection of symptoms.On the other hand instruments for the screening of BD have low sensitivity and limited diagnostic validity.
Criteria and subtypes There is no clear consensus as to how many types of bipolar disorder exist.In DSM-IV-TR and ICD-10, bipolar disorder is conceptualized as a spectrum of disorders occurring on a continuum. The DSM-IV-TR lists three specific subtypes and one for non-specified:
Bipolar I disorderOne or more manic episodes. Subcategories specify whether there has been more than one episode, and the type of the most recent episode. A depressive or hypomanic episode is not required for diagnosis, but it frequently occurs.Bipolar II disorderNo manic episodes, but one or more hypomanic episodes and one or more major depressive episode. However, a bipolar II diagnosis is not a guarantee that they will not eventually suffer from such an episode in the future.[citation needed] Hypomanic episodes do not go to the full extremes of mania (i.e., do not usually cause severe social or occupational impairment, and are without psychosis), and this can make bipolar II 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, crippling depression.CyclothymiaA history of hypomanic episodes with periods of depression that do not meet criteria for major depressive episodes.There is a low-grade cycling of mood which appears to the observer as a personality trait, and interferes with functioning.Bipolar Disorder NOS (Not Otherwise Specified)This is a catchall category, diagnosed when the disorder does not fall within a specific subtype. Bipolar NOS can still significantly impair and adversely affect the quality of life of the patient. The bipolar I and II categories have specifiers that indicate the presentation and course of the disorder. For example, the "with full interepisode recovery" specifier applies if there was full remission between the two most recent episodes.
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 of the above subtypes. It is defined as having four or more episodes per year and is found in a significant fraction of individuals with bipolar disorder. The definition of rapid cycling most frequently cited in the literature (including the DSM) is that of Dunner and Fieve: at least four major depressive, manic, hypomanic or mixed episodes are required to have occurred during a 12-month period. Ultra-rapid (days) or ultra-ultra rapid or ultradian (within a day) cycling have also been described.
Differential diagnosis There are several other mental disorders which may involve similar symptoms to bipolar disorder. These include schizophrenia,[56] schizoaffective disorder, drug intoxication, brief drug-induced psychosis, schizophreniform disorder and borderline personality disorder. Both borderline personality and bipolar disorder can involve what are referred to as "mood swings". In bipolar disorder, the term refers to the cyclic episodes of elevated and depressed mood which generally last weeks or months. The term in borderline personality refers to the marked lability and reactivity of mood, known as emotional dysregulation, due to response to external psychosocial and intrapsychic stressors; these may arise or subside suddenly and dramatically and last for seconds, minutes, hours or days. A bipolar depression is generally more pervasive with sleep, appetite disturbance and nonreactive mood, whereas the mood in dysthymia of borderline personality remains markedly reactive and sleep disturbance not acute. Some hold that borderline personality disorder represents a subthreshold form of mood disorder while others maintain the distinctness, though noting they often coexist.
Challenges The experiences and behaviors involved in bipolar disorder are often not understood by individuals or recognized by mental health professionals, so diagnosis may sometimes be delayed for over 10 years. The treatment lag is apparently not decreasing, even though there is increased public awareness of the condition.
Individuals are commonly misdiagnosed. An individual may appear simply depressed when they are seen by a health professional. This can result in misdiagnosis of Major Depressive Disorder. However, there is also a long-standing issue in the research literature as to whether a categorical classificatory divide between unipolar and bipolar depression is actually valid, or whether it is more accurate to talk of a continuum involving dimensions of depression and mania.
It has been noted that the bipolar disorder diagnosis is officially characterised in historical terms such that, technically, anyone with a history of (hypo)mania and depression has bipolar disorder whatever their current or future functioning and vulnerability. This has been described as "an ethical and methodological issue", as it means no one can be considered as being recovered (only "in remission") from bipolar disorder according to the official criteria. This is considered especially problematic given that brief hypomanic episodes are widespread among people generally and not necessarily associated with dysfunction.
Flux is the fundamental nature of bipolar disorder. Individuals with the illness have continual changes in energy, mood, thought, sleep, and activity. The diagnostic subtypes of bipolar disorder are thus static descriptions—snapshots, perhaps—of an illness in continual flux, 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 2013, will likely include further and more accurate sub-typing (Akiskal and Ghaemi, 2006).
The diagnosis of bipolar disorder can be complicated by coexisting psychiatric conditions such as obsessive-compulsive disorder, social phobia, panic disorder, or attention-deficit/hyperactivity disorder. Substance abuse may predate the appearance of bipolar symptoms, further complicating the diagnosis. A careful longitudinal analysis of symptoms and episodes, enriched if possible by discussions with friends and family members, is crucial to establishing a treatment plan where these comorbidities exist.