Environmental exposures can moderate the impact of genetic risk factors on a wide range of psychopathology (Kendler & Eaves, 1986; Moffitt, 2005; Rutter et al. 2006), including alcohol-related traits (Cloninger et al. 1981; Sigvardsson et al. 1996; Dick et al. 2001; Rose et al. 2001; Martens et al. 2007; Viken et al. 2007). However, with a recent exception (Hicks et al. 2009), such studies have typically explored one environmental exposure during one developmental period. Therefore, the secondary goal of this study was to determine whether, across adolescence, the impacts on alcohol consumption of (i) specific alcohol-related genetic risk factors and (ii) non-specific externalizing genetic risk factors are moderated by six relevant environmental exposures: alcohol availability, church attendance, peer group deviance, prosocial behaviors, parental bonding, and parental monitoring. We predicted that, during early adolescence, individuals at elevated genetic risk would be particularly sensitive to environments, which can act either as social constraints on or social triggers of alcohol consumption (Kendler, 2001; Shanahan & Hofer, 2005).
