OBJECTIVE - This study investigated whether the functional abnormalities in prefrontal systems observed in adult bipolar disorder are manifested in adolescents with this illness.
METHOD - Ten adolescents with bipolar disorder and 10 healthy comparison subjects participated in a color-naming Stroop task during event-related functional magnetic resonance imaging.
RESULTS - Signal increases in the left putamen and thalamus were significantly greater in the bipolar disorder group than in the healthy group. Age correlated positively with signal increases in the bilateral rostroventral prefrontal cortex and the striatum in the healthy group but not in the bipolar disorder group. In the bipolar disorder subjects, depressive symptoms correlated positively with signal increases in the ventral striatum.
CONCLUSIONS - These findings suggest the presence of dysfunction in the subcortical portions of the frontostriatal circuits in adolescents with bipolar disorder. The absence of the prefrontal abnormalities that were observed previously in adults and the absence of the age-related increases in prefrontal activity observed in normal comparison subjects suggest that a developmental disturbance in prefrontal function may emerge in bipolar disorder over the course of adolescence.