Bipolar Disorders in a Community Sample of Older Adolescents: Prevalence, Phenomenology, Comorbidity, and Course

The purpose of this study was to examine the prevalence, clinical characteristics, and mental health treatment services utilization of adolescents with bipolar disorders and manic symptoms. Structured diagnostic interviews were administered to a representative community sample of 1,709 older adolescents (aged 14 through 18 years). The lifetime prevalence of bipolar disorders (primarily bipolar II disorder and cyclothymia) was approximately 1%. An additional 5.7% of the sample reported having experienced a distinct period of abnormally and persistently elevated, expansive, or irritable mood even though they never met criteria for bipolar disorder (“core positive” subjects). The rate of manic symptoms in these subjects was similar to that reported in clinical samples, and the course of bipolar disorder was relatively chronic. Compared with adolescents with a history of major depression (n = 316) and a “never mentally ill” group (n = 845), the bipolar and core positive subjects both exhibited significant functional impairment and high rates of comorbidity (particularly with anxiety and disruptive behavior disorders), suicide attempts, and mental health services utilization. These data highlight the clinical and public health significance of even the milder and subthreshold cases of bipolar disorder in adolescence.