In 2010 a team led by Robert Miranda Jr., associate professor (research) of psychiatry and human behavior in the Warren Alpert Medical School of Brown University, found that teens with a single difference in their genes were more predisposed to alcohol use disorder. In a new study in Alcoholism: Clinical and Experimental Research he found that the risk was largely overcome in teens whose parents are attentive to their behavior and peer group. Miranda, a researcher at Brown’s Center for Alcohol and Addiction Studies, answered questions from science writer David Orenstein about the new study.
What did we know about genetic risk associated with A118G and teenage alcohol use going into this study?
In 2010, we reported in Alcoholism: Clinical and Experimental Research the first evidence that the A118G SNP of the OPRM1 gene is associated with a greater number of alcohol-related problems as well as the development of an alcohol use disorder (AUD) among adolescents. Specifically, adolescents who met criteria for an AUD diagnosis had a higher prevalence of the G allele (51.9 percent) than non-AUD youth(16.3 percent), and the G allele accounted for 9 percent of the variance in alcohol-related problems experienced by youth in the past three months, with a moderate effect size. Although these findings are consistent with some adult studies in terms of the nature and magnitude of this association, other adult studies did not find this relationship.
Overall, what did you find in the new research?
In this study, we took another look at our initial findings to test whether certain environmental factors, namely parenting practices and affiliation with deviant peers, influence the association between this particular genotype and alcohol-related problems in adolescents. We found that the association between this genotype and risk for an alcohol use disorder was moderated by these environmental factors, such that genetic liability was negligible for youth with high levels of parental monitoring and low affiliation with deviant peers. On the whole, this study highlights the importance of malleable environmental factors by showing greater parental monitoring and less affiliation with deviant peers can reduce genetic risk for developing alcohol use disorders.