Event-related potential correlates of inhibition in bipolar disorder

Lack of inhibitory control is a commonly reported impairment in patients with bipolar disorder, however, there has been little research regarding the time course of inhibitory processes. Twenty-six participants (13 bipolar and 13 controls) completed an emotional go/no-go inhibition task while event-related potentials were recorded. Go minus no-go difference waves were computed to index response inhibition. Across groups, there was greater activity in parietal and occipital compared with frontal and central electrodes. Longer latencies were found in bipolar disorder compared with controls. In conclusion, cortical regions recruited during response inhibition may be stimulus-dependent and not restricted to frontal areas. Impairments in bipolar disorder may relate to the speed at which inhibitory activity is executed, consistent with white matter deficits identified previously.