Perhaps especially worthy of consideration is the need to conduct alcohol-related GxE studies using endophenotypes (Gottesman & Gould, 2003) or intermediate phenotypes, measures that are closer to the pathophysiology of alcohol dependence than clinical diagnoses or consumption measures (e.g., alcohol-metabolizing enzymes, electroencephalographic markers, and event-related potentials) (Gunzerath & Goldman, 2003; Schuckit, 2000; Sher et al., 2010). Inclusion of such measures in alcohol-related GxE studies will supplement the use self-report measures of drinking behaviors and connect genetic variation to behavioral variation (e.g., Hutchison et al., 2008; Filbey et al., 2008), allowing for better selection of genes and environments based on biological plausibility.
