To replicate the genome-wide significant association of increased risk for depression in homozygous carriers of the A-allele of rs1545843, we performed an additional replication study with the UK-cases and controls of the RADIANT study(Lewis et al., 2010b) and adding the WTCCC2 control cohorts. This resulted in a cohort of 1636 cases with recurrent unipolar depression and 7246 controls. An analysis using logistic regression showed significant evidence for both an effect of the AA genotype on risk in the same direction as in the other studies (OR = 1.344, 95% CI 1.080–1.672, p = 0.008) as well as for an interaction of sex with this effect (p = 0.0150). The RADIANT/WTCCC2 study was the only study showing such sex × genotype interaction on depression. A more detailed description of this association is given in the supplemental data section. Finally, when combining the corrected estimate for the genotypic effect of AA on depression in the RADIANT/WTCCC2 study with the effects in the previous studies we arrive at an estimate of an OR = 1.398 (95% CI 1.254–1.557) with a combined two-sided p-value
