DRD2/ANKK1 TaqI A genotype moderates the relationship between alexithymia and the relative value of alcohol among male college binge drinkers

Binge drinking remains prevalent on college campuses (particularly among males), and a behavioral economic conceptualization of alcohol use provides novel insight into this problem. Further understanding also comes from identifying personality and genetic vulnerabilities associated with problem drinking among male college students. The present study hypothesized that DRD2/ANKK1 TaqI A (rs1800497) genotype would moderate the relationship between alexithymia and an alcohol purchase task (APT) among male college binge drinkers. Specifically, among individuals with at least 1 A1 allele (A1+), greater alexithymia would be related to higher breakpoint (the point at which consumption is 0), O(max) (maximum expenditure on consumption), P(max) (price at which maximum expenditure occurs), intensity (consumption at the lowest price), and lesser elasticity (sensitivity to increasing price). Secondary analyses aimed to replicate APT associations with problematic drinking (AUDIT) and alcohol-related problems (RAPI). Participants were 120 male European-American college student binge drinkers ( AUDIT: M=10.33, SD=4.41). Five Bonferroni-corrected moderation models were tested using APT indices as the criteria, alexithymia as the predictor, and DRD2/ANKK1 TaqI A1 allele presence as the moderator. Results indicated that, in A1+ individuals, greater alexithymia predicted lesser elasticity. Findings were not significant in A1- individuals. APT intensity was positively correlated with AUDIT total; however, no other significant relationships were found. This suggests that possession of the A1 allele interacts with hypoemotionality to predict a novel index of problem drinking. Results support the notion that college campuses would benefit from behavioral economic approaches to reduce binge drinking.