While variation in OPRM1 appears to increase the risk for developing problems with alcohol, genetic contributions to adolescent drinking are heavily influenced by environmental factors (Rose et al., 2001a, b). One factor that has received considerable attention within this context is parenting practices or more specifically parental monitoring, which includes both supervision of youth by a parent or other adult and communication between the parent and youth (Kerr and Stattin, 2000; Stattin and Kerr, 2000). A substantial body of literature has consistently demonstrated that higher levels of parental monitoring are associated with reduced risk of alcohol use as well as smoking and other risk-taking behaviors among adolescents (Beck et al., 2004; Guo et al., 2001; Lahey et al., 2008). Parental monitoring has been shown to moderate the influence of genetic effects on substance use in adolescence (Chen et al., 2009; Dick et al., 2007; 2009). For example, a twin study of adolescents ages 14 and 17 years found that genetic effects on substance use were significantly decreased as parental monitoring increased (Dick et al., 2007). Thus, lower levels of parental
