Clinical course of children and adolescents with bipolar spectrum disorders.

CONTEXT Despite the high morbidity associated with bipolar disorder (BP), few studies have prospectively studied the course of this illness in youth. OBJECTIVE To assess the longitudinal course of BP spectrum disorders (BP-I, BP-II, and not otherwise specified [BP-NOS]) in children and adolescents. DESIGN Subjects were interviewed, on average, every 9 months for an average of 2 years using the Longitudinal Interval Follow-up Evaluation. SETTING Outpatient and inpatient units at 3 university centers. PARTICIPANTS Two hundred sixty-three children and adolescents (mean age, 13 years) with BP-I (n = 152), BP-II (n = 19), and BP-NOS (n = 92). MAIN OUTCOME MEASURES Rates of recovery and recurrence, weeks with syndromal or subsyndromal mood symptoms, changes in symptoms and polarity, and predictors of outcome. RESULTS Approximately 70% of subjects with BP recovered from their index episode, and 50% had at least 1 syndromal recurrence, particularly depressive episodes. Analyses of weekly mood symptoms showed that 60% of the follow-up time, subjects had syndromal or subsyndromal symptoms with numerous changes in symptoms and shifts of polarity, and 3% of the time, psychosis. Twenty percent of BP-II subjects converted to BP-I, and 25% of BP-NOS subjects converted to BP-I or BP-II. Early-onset BP, BP-NOS, long duration of mood symptoms, low socioeconomic status, and psychosis were associated with poorer outcomes and rapid mood changes. Secondary analyses comparing BP-I youths with BP-I adults showed that youths significantly more time symptomatic and had more mixed/cycling episodes, mood symptom changes, and polarity switches. CONCLUSIONS Youths with BP spectrum disorders showed a continuum of BP symptom severity from subsyndromal to full syndromal with frequent mood fluctuations. Results of this study provide preliminary validation for BP-NOS.