The absence of a significant GxE interaction with recent major life events in our analysis is consistent with recent meta-analyses [9, 10], which are based primarily on samples of Caucasians. Nonetheless, we do find evidence of a GxE interaction with exposure to trauma, which has been less frequently studied than stressful life events. Consistent with Aguilera et al. [29], our results suggest that trauma has a greater effect on depressive symptoms for those with S/S or S/L genotypes than for those with L/L genotype, suggesting dominance of the S allele. However, other studies of trauma have found different patterns including additive and recessive effects of the S allele as well as a reversed relationship (L allele associated with greater risk); a few found no GxE interaction. Unlike some previous studies [11, 12, 30], we found no evidence that the GxE interaction varies by sex. Still, we are cautious about drawing firm conclusions in light of Munafò and colleagues’ contention [10] that most published studies are underpowered to examine these interactions1 and that variation in the pattern of the interaction across studies weakens researchers’ claims to have replicated Caspi’s original study.
