Selection of environmental risk factors and alcohol-related outcomes is challenging and marked by methodological limitations. Inconsistent and ad hoc approaches for measuring environmental risk decreased the sensitivity of alcohol-related GxE studies to detect interaction effects and complicated efforts to synthesize results. Additionally, measurement of alcohol-related outcomes was quite varied (e.g., alcohol initiation, drinking quantity/frequency, intoxication frequency, AUDs), and may have contributed to inconsistent evidence for GxE. Many alcohol-related GxE studies collected information on environmental exposures and drinking outcomes at the same measurement occasion, raising concerns about the causal nature of environmental risk factors and drinking outcomes. Several of the “environmental” measures in the reviewed studies, such as SLEs or parental rules about drinking, are arguably the consequence of an individual’s (or his or her parents’) drinking, rather than a contributing factor, limiting the interpretation of GxE.
