We conducted a GWAS meta-analysis based on expanded data from iPSYCH (25,895 cases; 37,148 controls), deCODE genetics (8,281 cases; 137,993 controls) and published data from 10 ADHD cohorts with European ancestry collected by the PGC (4,515 cases; 11,702 controls), resulting in a total sample size of 38,691 individuals with ADHD and 186,843 controls (effective sample size (neff_half) = 51,568; cohorts listed in Supplementary Table 1).
