Three studies have examined whether variation in the CRHR1 gene moderates environmental risk for alcohol-related outcomes. In a German sample of 15-year-olds, Blomeyer and colleagues (2008) found that variation at one CRHR1 SNP (rs1876831, C or T alleles) interacted with severe SLEs experienced during the past three years: adolescents with the CC genotype who experienced high rates of SLEs were approximately twice as likely to report lifetime heavy drinking and had twice the number of maximum drinks per drinking occasion compared to those with TT or CT genotypes and those with low SLEs regardless of genotype. There was no GxE with respect to current monthly drinking or average drinks per month. A similar pattern of GxE was observed four years later when participants were aged 19 (Schmid et al, 2010). The final study found that a CRHR1 haplotype (chromosomal region) (including rs1876831) interacted with childhood sexual abuse (CSA), such that CSA was associated with greater alcohol consumption and AD only among adults who had two copies (i.e., were homozygous) of the haplotype that included the rs1876831 C allele (Nelson et al., 2010).
