More than 90% of individuals who have a single manic episode go on to have recurrent mood episodes. Approximately 60% of manic episodes occur immediately before a major depressive episode. Individuals with bipolar I disorder who have multiple (four or more) mood episodes (major depressive, manic, or hypomanic) within 1 year receive the speci- fier “with rapid cycling.”
Environmental. Bipolar disorder is more common in high-income than in low-income countries (1.4 vs. 0.7%). Separated, divorced, or widowed individuals have higher rates of bipolar I disorder than do individuals who are married or have never been married, but the direction of the association is unclear.
Genetic and physiological. A family history of bipolar disorder is one of the strongest and most consistent risk factors for bipolar disorders. There is an average lO-fold increased risk among adult relatives of individuals with bipolar I and bipolar II disorders. Magnitude of risk increases with degree of kinship. Schizophrenia and bipolar disorder likely share a ge- netic origin, reﬂected in familial co-aggregation of schizophrenia and bipolar disorder.
Course modifiers. After an individual has a manic episode with psychotic features, subse- quent manic episodes are more likely to include psychotic features. Incomplete inter- episode recovery is more common when the current episode is accompanied by mood— incongruent psychotic features.
Little information exists on specific cultural differences in the expression of bipolar I dis- order. One possible explanation for this may be that diagnostic instruments are often translated and applied in different cultures with no transcultural validation. In one US.
study, 12-month prevalence of bipolar I disorder was significantly lower for Afro-Carib- beans than for African Americans or whites.
Females are more likely to experience rapid cycling and mixed states, and to have patterns of comorbidity that differ from those of males, including higher rates of lifetime eating disor- ders. Females with bipolar I or II disorder are more likely to experience depressive symptoms than males. They also have a higher lifetime risk of alcohol use disorder than are males and a much greater likelihood of alcohol use disorder than do females in the general population.
The lifetime risk of suicide in individuals with bipolar disorder is estimated to be at least 15 times that of the general population. In fact, bipolar disorder may account for one-quar- ter of all completed suicides. A past history of suicide attempt and percent days spent de- pressed in the past year are associated with greater risk of suicide attempts or completions.
Functional Consequences of Bipoiar I Disorder
Although many individuals with bipolar disorder return to a fully functional level be- tween episodes, approximately 30% show severe impairment in work role function. Func- tional recovery lags substantially behind recovery from symptoms, especially with respect to occupational recovery, resulting in lower socioeconomic status despite equivalent lev- els of education when compared with the general population. Individuals with bipolar I disorder perform more poorly than healthy individuals on cognitive tests. Cognitive im- pairments may contribute to vocational and interpersonal difficulties and persist through the lifespan, even during euthymic periods.
Major depressive disorder. Major depressive disorder may also be accompanied by hy- pomanic or manic symptoms (i.e., fewer symptoms or for a shorter duration than required for mania or hypomania). When the individual presents in an episode of major depression, one must depend on corroborating history regarding past episodes of mania or hypoma- nia. Symptoms of irritability may be associated with either major depressive disorder or bipolar disorder, adding to diagnostic complexity.
Other bipolar disorders. Diagnosis of bipolar I disorder is differentiated from bipolar II disorder by determining whether there have been any past episodes of mania. Other spec- and II disorders by considering whether either the episodes involving manic or hypo- manic symptoms or the episodes of depressive symptoms fail to meet the full criteria for those conditions.
Bipolar disorder due to another medical condition may be distinguished from bipolar