The relationship of impulsivity to response inhibition and decision-making in remitted patients with bipolar disorder.

Background: Impulsivity, a core feature of bipolar disorder (BD), is a multifaceted concept encompassing failure of response inhibition and poor decision-making. Abnormalities in these two cognitive domains have been reported in BD patients but their relationship with impulsivity has not been explored.
Methods: Twenty-five remitted patients with BD completed the Barratt Impulsiveness Scale (BIS) and performed the Hayling Sentence Completion Task (HSCT) and a computerized version of the Iowa Gambling task. The HSCT total errors scaled score was used as a measure of response inhibition while the gabling task score, which reflects participants' ability to make advantageous choices, was used a measure of decision making.
Results: Higher scores on the BIS attentional and non-planning subscales were respectively associated with more errors in the HSCT and less advantageous choices in the gambling task.
Limitations: All patients were medicated. Healthy participants were not included.
Conclusions: Viewed in the context of recent relevant studies our findings suggest that impulsivity, response inhibition and decision-making in BD may represent behavioural manifestations of the same underlying biological mechanism possibly linked to ventral prefrontal cortical function.