Controlled study of switching from attention-deficit/hyperactivity disorder to a prepubertal and early adolescent bipolar I disorder phenotype during 6-year prospective follow-up: rate, risk, and predictors.

Rate, risk, and predictors of switching from attention-deficit/hyperactivity disorder (ADHD) to a prepubertal and early adolescent bipolar I disorder phenotype (PEA-BP-I) were examined in a blindly rated, controlled, prospective 6-year follow-up that included assessments at 2-year intervals. Subjects were outpatients obtained by consecutive new case ascertainment. There were 81 subjects who were 9.7 +/- 2.0 years. Subjects had DSM-IV ADHD (hyperactive or combined subtypes); a Children's Global Assessment Scale (CGAS) score of < or =60, consistent with moderate-severe impairment; and no BP or major depressive disorder (MDD) diagnoses. PEA-BP-I was defined as DSM-IV BP I (manic or mixed phase), with cardinal symptoms (elation and/or grandiosity), to avoid diagnosing mania by symptoms that overlapped with those of ADHD, and by a CGAS score of < or =60. Morbid risk of switching to PEA-BP-I was 28.5%. Significant predictors of switching in a multivariate Cox model were more severe baseline CGAS, paternal recurrent MDD, and less stimulant use. BP I in first-degree relatives, antidepressants, psychosocial measures, and life events were not predictive.