Genetic Vulnerability to Alcohol Use

Dr. McChargue has an interest in how endophynotypes contribute to harmful binge drinking and whether these etiological factors predict vulnerability to future alcohol dependence. Endophynotypic exploration assesses the interaction between genotypes and behavioral vulnerabilities on disease outcome. For example, preliminary data with Dr. Mcchargue’s lab shows that D2 dopamine receptor genes moderate the relation between neuroticism with addictive “liking” and “wanting” processes of incentive-sensitization among female college students (Herschl & McChargue, 2009). Incentive-sensitization (I-S) theory posits that as the behavioral drive (wanting) for the substance increases with concomitant decreases in substance-related hedonia (liking), the organism becomes more addicted to the substance and that this addiction reflects a sensitized dopamine system. Consistent with this theory, Dr. McChargue’s lab shows that 24% of the binge drinking population (6 > weekend drinks for males; 4 > weekend drinks for females) exhibit strong I-S effects (strong wanting with low liking). Further, a predisposition to have greater reward sensitivity (DRD2) interacts with trait features of negative affect vulnerability to predict I-S effects. Specifically, only among females with an A1 allele does neuroticism influence I-S responding. Future research plans involve the longitudinal investigation of the interaction between dopamine genotypes and affect vulnerability on the development of alcohol addiction within college students. In addition, the lab is interested in understanding the link between multi-systemic genotyping (serotonin, MAO, dopamine) on endophynetic effects of alcohol-related I-S responding.