Wray et al. conducted the largest meta-analysis of MDD to date 9, utilising European-ancestry PGC cohorts with an emphasis placed on obtaining clinically-derived phenotypes for MDD. Their meta-analysis included the 23andMe_307k discovery cohort 8 and a previous release of the UK Biobank data 55. We therefore obtained the summary statistics from their meta-analysis of major depression with the 23andMe_307k and the previous UK Biobank cohorts removed (PGC_139k). This provided a total of 12,149,399 variant calls for 43,204 cases and 95,680 controls (n = 138,884, prevalence = 0.31). We excluded variants with an imputation accuracy threshold < 0.6 or a minor allele frequency < 0.005, which left a total of 10,365,555 variants.
