The iPSYCH samples were genotyped, processed, and analyzed in 23 separate waves. See Supplemental Table S1 for sex-stratified sample sizes for each PGC study and iPSYCH wave. The total sample size after all quality control was n = 20,183 cases (25% female) and n = 35,191 pseudocontrols/population controls (38% female). Analyses that were restricted to European-only samples consisted of 19,099 cases and 34,194 controls. ADHD GWAS summary statistics were also available from research participants of the personal genetics company 23andMe Inc. (n = 5857 self-reported ADHD cases, n = 70,393 controls) (Mountain View, CA).
