Child bipolar I disorder: prospective continuity with adult bipolar I disorder; characteristics of second and third episodes; predictors of 8-year outcome

Abstract

Context: Child bipolar I disorder (BP-I) is a contentious diagnosis.

Objective: To investigate continuity of child and adult BP-I and characteristics of later episodes.

Design: Inception cohort longitudinal study. Prospective, blinded, controlled, consecutive new case ascertainment.

Setting: University medical school research unit. Subjects There were 115 children, enrolled from 1995 through 1998, aged 11.1 (SD, 2.6) years with first episode DSM-IV BP-I, mixed or manic phase, with 1 or both cardinal symptoms (elation or grandiosity) and score of 60 or less on the Children's Global Assessment Scale (CGAS). All DSM-IV severity and duration criteria were fulfilled. Separate interviews were conducted of parents about their children and of children about themselves.

Main outcome measures: Washington University in St Louis Kiddie Schedule for Affective Disorders and Schizophrenia (WASH-U-KSADS); Psychosocial Schedule for School Age Children-Revised; CGAS.

Results: Retention was 93.9% (n = 108) for completing assessments at every one of the 9 follow-up visits. Subjects spent 60.2% of weeks with any mood episodes and 39.6% of weeks with mania episodes, during 8-year follow-up. During follow-up, 87.8% recovered from mania, but 73.3% relapsed to mania. Even accounting for family psychopathology, low maternal warmth predicted relapse to mania, and more weeks ill with manic episodes was predicted by low maternal warmth and younger baseline age. Largely similar to first episodes, second and third episodes of mania were characterized by psychosis, daily (ultradian) cycling, and long duration (55.2 and 40.0 weeks, respectively), but significantly shorter than first episodes. At 8-year follow-up, 54 subjects were 18.0 years or older. Among subjects 18.0 years or older, 44.4% had manic episodes and 35.2% had substance use disorders.

Conclusions: In grown-up subjects with child BP-I, the 44.4% frequency of manic episodes was 13 to 44 times higher than population prevalences, strongly supporting continuity. The rate of substance use disorders in grown-up child BP-I was similar to that in adult BP-I.

Figure 1

Cumulative probability of recovery from first episode (baseline) of child bipolar I disorder, manic or mixed phase. Life-table estimate of recovery was 95.2% (95% confidence interval, 90.6%–99.8%). The 9 assessment points are indicated.

Figure 2

Cumulative probability of survival after recovery from the first episode (baseline) of child bipolar I disorder (BP-I), manic or mixed. The solid curve is the probability of survival for the 101 subjects with BP-I who recovered. Life-table estimate of survival was 22.2% (95% confidence interval [CI], 13.4%–31.0%). For the 52 subjects with high maternal warmth, life-table estimate of survival was 37.3% (95% CI, 23.2%–51.4%). For the 49 subjects with low maternal warmth, life-table estimate of survival was 4.0% (95% CI, 0.0%–11.3%). Cox proportional hazards modeling was significant for maternal warmth (χ²=10.7, P=.001), controlling for baseline age, sex, and variables significant in univariate models (baseline Children’s Global Assessment Scale score, ascertainment site, baseline major depressive disorder, baseline conduct disorder, maternal tension/hostility, paternal warmth, and parent with BP-I or recurrent major depressive disorder). The hazard ratio was 2.9 (95% CI, 1.5–5.4).