No abstract

This study investigated whether automatic approach action tendencies for alcohol-related stimuli were associated with variation in the mu-opioid receptor gene (OPRM1), previously related to rewarding effects of alcohol and craving. An adapted approach avoidance task was used, in which participants pulled or pushed a joystick in reaction to the format of a picture shown on the computer screen (e.g. pull landscape pictures and push portrait pictures). Picture size on the screen changed upon joystick movement, so that upon a pull movement picture size increased (creating a sense of approach) and upon a push movement picture size decreased (avoidance). Participants reacted to four categories of pictures: alcoholrelated, other appetitive, general positive and general negative. The sample consisted of 84 heavy drinking young men without a g-allele in the A118G (or A355G) single nucleotide polymorphism of the OPRM1 gene and 24 heavy drinking young men with at least one g-allele.Heavy drinking carriers of a g-allele showed relatively strong automatic approach tendencies for alcohol (approach bias). Unexpectedly, they also showed an approach bias for other appetitive stimuli. No approach bias was found for general positive or negative stimuli. These results suggest that automatic approach tendencies in response to appetitive stimuli could play a role in the etiology of addictive behaviors and related disorders. Further research is needed to investigate the specificity of this approach bias and possible gender differences.

Aims To test whether an expectancy challenge (EC) changes implicit and explicit alcohol-related cognitions and binge drinking in young heavy drinkers. This is important for theoretical and practical reasons: the EC presents a critical test for the hypothesized mediational role of alcohol cognitions and the EC has been presented as a promising intervention to counter alcohol problems in heavy drinking youth. Setting, participants and intervention Ninety-two heavy drinking college and university students (half women) were assigned randomly to the EC or control condition (a sham alcohol experiment in the same bar-laboratory). Measurements Explicit alcohol cognitions and alcohol use were assessed with paper-and-pencil measures. Alcohol use was assessed prior to the experiment and during a 1-month follow-up. Implicit alcohol-related cognitions were assessed with two versions of the Implicit Association Test (IAT), adapted to assess implicit valence and arousal associations with alcohol. Findings and conclusions The EC resulted in decreased explicit positive arousal expectancies in men and women alike. There was some evidence for a differential reduction in implicit arousal associations, but findings depended on the version of the IAT and on the scoring-algorithm used. In men (but not in women) there was a short-lived differential reduction in prospective alcohol use (significant in week 3 of the follow-up), and this reduction was partially mediated by the decrease in explicit positive arousal expectancies. These findings suggest that an EC successfully changes explicit alcohol cognitions and that this may have short-lived beneficial effects in heavy drinking young men.

A stronger urge to drink alcohol after exposure to an alcoholic beverage might contribute to a heightened risk for developing alcohol-related problems in individuals with a copy of the G allele. The G allele might also predispose to drug use in general.

Polymorphisms in the D4 dopamine receptor gene (DRD4) and the CB1 cannabinoid receptor gene (CNR1) have been associated with a differential response to alcohol after consumption. The goal of the present study was to investigate whether heavy drinkers with these polymorphisms would respond with enhanced cue-reactivity after alcohol exposure. Eighty-eight male heavy drinkers were genotyped for the DRD4 variable number of tandem repeats (VNTR) [either DRD4 long (L) or short (S)] and the CNR1 rs2023239 polymorphism (either CT/CC or TT). Participants were exposed to water and beer in 3-minute trials. Dependent variables of main interest were subjective craving for alcohol, subjective arousal and salivary reactivity. Overall, no strong evidence was found for stronger cue-reactivity (= outcome difference between beer and water trial) in the DRD4 L and CNR1 C allele groups. The DRD4 VNTR polymorphism tended to moderate salivary reactivity such that DRD4 L participants showed a larger beverage effect than the DRD4 S participants. Unexpectedly, the DRD4 L participants reported, on average, less craving for alcohol and more subjective arousal during cue exposure, compared with the DRD4 S participants. As weekly alcohol consumption increased, the CNR1 C allele group tended to report more craving for alcohol during the alcohol exposure than the T allele group. The DRD4 and CNR1 polymorphisms do not appear to strongly moderate cue-reactivity after alcohol cue exposure, in male heavy drinkers.