For replication we evaluated the comparison of the GWAS meta-analysis of ADHD with three other independent ADHD-related GWASs: replication of top loci in an Icelandic cohort with ADHD status derived from medical records of ICD codes and medication history by deCODE (5,085 cases, 131,122 controls), a GWAS of self-reported ADHD status among 23andMe research participants (5,857 cases, 70,393 controls) and a meta-analysis of GWAS of childhood rating scales of ADHD symptoms performed by the EAGLE consortium (17,666 children < 13 years of age)30 and QIMR92 (2,798 adolescents), referred to as EAGLE/QIMR throughout the text. Although the phenotyping and cohort ascertainment of the 23andMe and EAGLE/QIMR studies differ from the PGC and iPSYCH ADHD meta-analysis (Supplemenatry Information), they have clear relevance to understanding how the ADHD GWAS results generalize to closely related phenotypes.
