Alcohol-predictive cues enhance tolerance to and precipitate "craving" for alcohol in social drinkers

Abstract

This study attempts to show that tolerance to alcohol is in large part a "learned" response, precipitated by contextual cues predictive of the unconditional drug effect. It also aims to show that the contextual cues integral to such "environment-dependent" tolerance function to increase motivational desire to drink alcohol. Male students (N = 40), drinking on average 10-20 units of alcohol per week, were randomly assigned to one of four groups. Two groups ingested 1.2ml/kg alcohol: one (AL-EXPT) with exteroceptive contextual cues typically associated with alcohol use, and the other (AL-UNEXPT) in a context not normally associated with alcohol. A third group (placebo) believed that they were drinking alcohol but, in fact, consumed a nonalcoholic beverage in the alcohol-expected context. The fourth group drank juice in the alcohol-unexpected context. As predicted, tolerance to the deleterious effects of alcohol on cognition and motor-performance, and subjective desire to consume alcohol, were influenced by the alcohol-predictive contextual cues. A physiological index (pulse rate) also tended to confirm that these cues elicited a conditioned compensatory response to alcohol. The implications of these findings for tolerance to and motivation to drink alcohol in a nonpathological population are discussed.