Different Trajectories of Adolescent Alcohol Use: Testing Gene–Environment Interactions

Background Transitions into heavy alcohol use often already take place during adolescence and are likely to be both genetically and environmentally determined. Therefore, in a 6‐wave longitudinal study, we examined the effects of DRD 2 T aq1 A and OPRM 1 A 118 G genotypes and the interaction with parental rule‐setting on different groups of adolescent drinkers. Methods Growth mixture modeling resulted in 3 distinct groups of adolescent drinkers: light drinkers ( n  =   346), moderate drinkers ( n  =   178), and heavy drinkers ( n  =   72). Results Multinomial regression showed that moderate drinkers carried the OPRM 1 G allele and received lower levels of parental rule‐setting significantly more often than the light drinking group. No other significant main effects of DRD 2 , OPRM 1 , and rule‐setting were found. The interaction between OPRM 1 genotype and parental rule‐setting significantly distinguished the heavy drinkers from the light ( p  < 0.001) and moderate groups ( p =  0.055): Particularly, the alcohol use of OPRM 1 G allele carriers was affected by parental rule‐setting, while AA genotype carriers remained largely unaffected by parental rules. Conclusions Findings showed that different trajectories of adolescent drinking are preceded by a gene–parenting interaction. These results concur with B elsky's theory of plasticity (2009), as well as with S hanahan and H ofer's typology of a controlling and restricting gene–environment interaction (2005).