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 monitoring were found to allow for greater expression of genetic predispositions demonstrating that the etiology of adolescent smoking varies dramatically as a function of parental monitoring. Similar effects were found in a prospective study that examined the association between a specific gene (GABRA2) and alcohol-related problems in a community-based sample of adolescents; the significant association between the candidate gene and alcohol misuse diminished with high levels of parental monitoring (Dick et al., 2009). These studies lend support to the role of parental monitoring as a moderator of genetic effects on substance use in adolescence.
