Following the identification of associations of two SNPs in intron 3 and intron 6 regions of CRHR1 with binge drinking in adolescents and with high amount of drinking in adults but not with alcohol dependence diagnosis (Treutlein et al., 2006), the same research group recently investigated the interaction between these two SNPs in CRHR1 and negative stressful life events in adolescents at age 15, in an attempt to understand the mechanisms underlying the gene-environment interaction and alcohol drinking (Blomeyer et al., 2008). Significant interactions between one SNP, rs1876831 in intron 6, and life stress on heavy drinking were found, revealing an effect of negative life events on heavy drinking only among individuals carrying a particular genotype of CRHR1. The findings are parallel to recent reports of significant associations of the short allele of the serotonin transporter gene 5-HTTLPR with depression under life stress (Caspi et al., 2003; Dick et al., 2007). For alcohol dependence, some studies (e.g., Parsian and Cloninger, 2001) have reported association with the long allele of the 5-HTTLPR polymorphism, others have found association with the short allele
