Evidence of deficits in behavioural inhibition and performance monitoring in young female heavy drinkers.

Background: New models of the development and maintenance of substance abuse give increasing importance to the role of deficits in inhibitory function. Much of the evidence to support this claim comes from male participants, despite some researchers showing greater disinhibition in females. Clearly, more research on female heavy drinkers is warranted. In this study, we examine behavioural and psychophysiological measures of inhibitory function in female young adults who do and do not regularly drink heavily.

Methods: Participants were thirty female young adults (aged 18-21) who drink heavily (four or more standard drinks per occasion) at least once a month (n=13) or who drink heavily less often than this (n=17); none regularly used any other drugs, including tobacco. They underwent interviews assessing prior use of alcohol, before completing a stop-signal task while brain electrical activity was recorded.

Results: Regular heavy drinkers displayed a longer stop-signal reaction time (the time required to stop an inappropriate response), and a larger P3 increase for successful compared to failed inhibition trials. Heavy drinkers also displayed a smaller error-related negativity (ERN) amplitude, indexing a deficit in performance monitoring.

Conclusion: These results indicate that large deficits in inhibitory processing and performance monitoring occur in young female heavy drinkers, and that heavy drinkers may have to work harder in order to successfully inhibit a response. Future research may determine whether these deficits pre-date or are caused by alcohol abuse.