Mendelian randomization analysis of significant LD independent psychiatric trait SNPs (r2 < 0.05, based on 1000 G Phase 3 CEU samples), where the threshold for significance was set to P < 5 × 10−7 due to having less than the required 10 significant independent SNPs at the program default P < 5 × 10−8 for MDD. Estimates of heritability, genetic correlation, and sample overlap of psychiatric trait and PTSD GWAS were estimated using precomputed LD scores based on 1000 G Europeans that were supplied with LDSC (https://data.broadinstitute.org/alkesgroup/LDSCORE/eur_w_ld_chr.tar.bz2).
