Impulsivity predicts the onset of DSM-IV-TR or RDC hypomanic and manic episodes in adolescents and young adults with high or moderate reward sensitivity.

Background: A growing body of research suggests that bipolar disorders (BD) are associated with high impulsivity. Using a multi-method approach, the current study provided the first examination of the hypothesis that impulsivity would prospectively predict shorter time to onset of DSM-IV-TR or RDC hypomanic or manic episodes in a sample selected based on reward sensitivity, a biobehavioral trait shown to predict onset and course of BD.

Methods: 163 participants with high reward sensitivity and 114 participants with moderate reward sensitivity were followed every six months for an average of 2.68 years. Participants completed the Barratt Impulsiveness Scale - Version 11 (BIS-11), Balloon Analog Risk Task (BART), Beck Depression Inventory, Altman Self-Rating Mania Scale, and an expanded Schedule for Affective Disorders and Schizophrenia (exp-SADS) - Lifetime Version at baseline and were followed prospectively with the exp-SADS - Change Version to assess onset of hypomanic or manic episodes and treatment seeking for mood problems.

Results: Cox proportional hazard regression analyses indicated that impulsivity as measured by a behavioral task (BART; OR=1.04, p=.03) and a self-report measure (BIS-11 Attentional Impulsiveness subscale; OR=1.16, p=.01) predicted shorter time to hypomania/mania onset, after controlling for baseline depressive and manic symptoms, family history of mood disorder, treatment seeking for mood problems, and reward sensitivity.

Limitations: The study was limited by non-comprehensive assessment of impulsivity and unknown generalizability to clinical samples.

Conclusions: Impulsivity confers vulnerability to hypomania or mania. Future studies would benefit from considering how impulsivity can be integrated into existing biopsychosocial models of BD.