Four-year prospective outcome and natural history of mania in children with a prepubertal and early adolescent bipolar disorder phenotype

Abstract

Background: Diagnosis of child mania has been contentious.

Objective: To investigate natural history and prospective validation of the existence and long-episode duration of mania in children.

Design: Four-year prospective longitudinal study of 86 subjects with intake episode mania who were all assessed at 6, 12, 18, 24, 36, and 48 months. The phenotype was defined as DSM-IV bipolar I disorder (manic or mixed) with at least 1 cardinal symptom (elation and/or grandiosity) to ensure differentiation from attention-deficit/hyperactivity disorder. Parent and child informants were separately interviewed, by highly experienced research nurses, using the Washington University in St Louis Kiddie Schedule for Affective Disorders and Schizophrenia (WASH-U-KSADS). A Children's Global Assessment Scale score of 60 or less was needed to establish definite impairment. Treatment was by subjects' community practitioners.

Setting: Research unit in a university medical school.

Participants: Subjects were obtained from psychiatric and pediatric sites by consecutive new case ascertainment, and their baseline age was 10.8 +/- 2.7 years. Onset of the baseline episode was 7.4 +/- 3.5 years. (Data are given as mean +/- SD.)

Main outcome measures: Episode duration, weeks ill, recovery/relapse rates, and outcome predictors.

Results: Prospective episode duration of manic diagnoses, using onset of mania as baseline date, was 79.2 +/- 66.7 consecutive weeks. Any bipolar disorder diagnosis occurred during 67.1% +/- 28.5% of total weeks, during the 209.4 +/- 3.3 weeks of follow-up. Subjects spent 56.9% +/- 28.8% of total weeks with mania or hypomania (unipolar or mixed), and 38.7% +/- 28.8% of these were with mania. Major or minor depression and dysthymia (unipolar or mixed) occurred during 47.1% +/- 30.4% of total weeks. Polarity switches occurred 1.1 +/- 0.7 times per year. Low maternal warmth predicted faster relapse after recovery from mania (chi(2) = 13.6, P =.0002), and psychosis predicted more weeks ill with mania or hypomania (F(1,80) = 12.2, P =.0008). Pubertal status and sex were not predictive. (Data are given as mean +/- SD.)

Conclusions: These findings validate the existence, long-episode duration, and chronicity of child mania. Differences from the natural history of adult bipolar disorder are discussed.