Our SCZ GWAS meta-analysis involved 18 studies. After stringent quality control, 1 085 772 genotyped and imputed SNPs were available for 21 953 subjects of European descent (11 185 cases and 10 768 controls). To account for possible population stratification within each of the GWASs, we included the first 3 principal components from the EigenSoft package (Helix Systems)10 plus any additional components that predicted case-control status (P≤.05). Additional details about the study samples and the methods can be found in eMethods 1, eTable 1, and eFigures 1 through 6 (http://www.jamapsych.com).
