We recently reported 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 AUD among adolescents (Miranda et al., 2010). Specifically, adolescents who met criteria for an AUD diagnosis had a higher prevalence of the G allele (51.9%) than non-AUD youth (16.3%), and the G allele accounted for 9% of the variance in alcohol-related problems experienced by youth in the past 3 months, with a medium magnitude effect size (f = 0.31).These findings coincide with adult studies in terms of the nature and magnitude of the association between OPRM1 and alcoholism (Bart et al., 2005; Town et al., 1999; for a review, see Ray et al., 2012). It is important to recognize, however, that a number of adult studies did not find this association (Franke et al., 2001; Loh et al., 2004; Lou et al., 2003).
