Deficient inhibition in alcohol-dependence: What is the impact of craving ?

A deficit in preparatory inhibition, as well as craving induced by alcohol-related cues are thought to be two important contributors to the maintenance of dependence. The present study aimed at testing whether the induction of a craving, using an alcohol-cue exposure performed in virtual reality, could influence the level of physiological preparatory inhibition. Ten detoxified alcohol-dependent (AD) patients and ten control subjects were exposed to a bar and a library environment. Right after the exposure, preparatory inhibition was evaluated with double-coil transcranial magnetic stimulation applied to elicit motor-evoked potentials (MEPs) in both hands when the subject was performing an instructed-delay reaction time task. Moreover, craving was assessed at different time points across the experiment. Results revealed a weaker MEP suppression during action preparation in AD patients relative to control subjects. However, this MEP suppression was not significantly altered following the alcohol-related exposure. Finally, our data showed a slight increase in the level of craving in AD patients at the end of the experiment, but not right after the alcohol-related context. Overall, this study confirms that AD patients suffer from a deficit in preparatory inhibition and suggests that an exposure to an alcohol-related context has no impact on the strength of preparatory inhibition. Nevertheless, influences of a craving are still to be clarified.