The manifestation of impulsivity in bipolar disorder involves some of the problems with response inhibition/action restraint observed in alcoholic patients (Easton et al., 2008). Swann and colleagues (2009b) report that patients with bipolar disorder made fewer correct detections during performance of the continuous performance task, indicative of reduced attention, reduced accuracy, and slower reaction times. These aspects of performance were taken as difficulty in organizing a delayed response, or as a result of a compensatory mechanism whereby errors of commission are reduced at the cost of slower responses. Reaction times were, however, faster in patients with highly recurrent illness or history of alcohol- or substance-use disorders than in patients with bipolar disorder without these features, suggesting failure of this compensatory mechanism. These abnormalities persisted across affective states and were present regardless of pharmacological treatment (Swann et al., 2009b).
