We first examined the association between allele frequency and number of stressful life events within those without depression, our proxy for testing for gene-environment correlation in the population. No significant relationship was found between genotype and number of life events among those without depression for both sexes combined (eTable 2) or for males or females alone (eTable 3) in most of the individual studies, or in the metaanalysis (β, −0.003; SE, 0.014). Likewise, there was no association between stressful life events and allele frequency within those with depression either in the individual studies, except for the studies of Caspi et al10 (positive regression) and Cervilla et al15 (negative regression), or in the meta-analysis (β, −0.004 ; SE, 0.034). However, the meta-analysis yielded no significant differences in the β coefficients between those with and without depression across studies (β, −0.001; SE, 0.047) and sexes, indicating a lack of gene environment interaction.
