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 ≤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 ≤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.This work was
supported by National Institute of Mental Health Grants R01 MH-53063 and
R01 MH-57451 (to B.G.).