Our results extend and clarify a prior report (Blomeyer et al. 2008) in which a significant G × E interaction involving severe stressors over the prior three years and the minor allele of rs1876831, a CRHR1 SNP, led to protection against alcohol consumption in adolescents. We found evidence of a similar interaction and demonstrated that it involves the ~1.5 Mb H2 haplotype spanning several genes in this region of chromosome 17. rs1876831 is one of many informative markers that can be used to tag this haplotype. Another important feature that distinguishes our study from the prior report is that our larger, substantially older sample has already passed through the period of greatest risk for problematic alcohol use enabling an examination lifetime measures, peak ACFS and DSM-IV alcohol dependence diagnosis, that characterize respondents’ mature drinking patterns. Both of these measures have excellent psychometric properties and have been shown to be at least moderately heritable (Heath et al. 1997; Bucholz et al. 1994; Agrawal et al. 2009; Grant et al. 2009). Our findings demonstrate that the protection against CSA-associated risk for problematic
