Prospectively Ascertained Mania and Hypomania among Young Adults with Child- and Adolescent-Onset Bipolar Disorder.

Objectives: While adults with bipolar disorder (BD) often report symptoms starting in childhood, continuity of mania and/or hypomania (mania/hypomania) from childhood to adulthood has been questioned. Using longitudinal data from the Course and Outcome of Bipolar Youth (COBY) study, we assessed threshold mania/hypomania in young adults who manifested BD as youth. Methods: COBY is a naturalistic, longitudinal study of 446 youth with BD (84% recruited from outpatient clinics), 7-17 years old at intake, and over 11 years of follow-up. Focusing on youth with BD-I/II (n = 297), we examined adult mania/hypomania risk (>18 years old; mean 7.9 years of follow-up) according to child (<13 years old) versus adolescent (13-17 years old) onset. We next used penalized regression to test demographic and clinical predictors of young adult mania/hypomania. Results: Most participants (64%) had child-onset mania/hypomania, 57% of whom also experienced mania/hypomania in adolescence. Among those who experienced an episode in adolescence, over 40% also had mania/hypomania during adulthood; the risk did not differ according to child versus adolescent onset. In contrast, 7% with mania/hypomania in childhood, but not adolescence, experienced mania/hypomania in adulthood. Family history (of mania and suicide attempts) predicted mania/hypomania in young adulthood (p-values <0.05); age of onset was not a significant predictor. Among participants with no mania/hypomania during adulthood, 53% (105/198) still experienced subthreshold manic episodes. Discussion: We find substantial continuity across developmental stage indicating that, in this carefully characterized sample, children who experience mania/hypomania-particularly those who also experience mania/hypomania in adolescence-are likely to experience mania/hypomania in young adulthood.