Next, we retrieved 11 independent datasets of drug addiction GWAS [25-31] (See Details in Methods). Among them five datasets met our criteria for inclusion [25-27]. We integrated the five GWAS datasets using a new meta-analysis approach to select positive SNPs with significantly more GWAS support than expected by chance (See Details in Methods). Overall, 842 SNPs were supported by at least three items of positive evidence, with meta-false discovery rates less than 0.05 (Additional file 3).
