SHANK2 and attention deficit-hyperactivity disorder: This ADHD GWAS in its publication, including supplementary results, reported 12 genome-wide significant loci, but none of them was related to SHANK2. However, its sample sizes of 20,183 ADHD participants and 35,191 controls are not considered to be particularly large by comparison to those involved in other common psychiatric disorders, e.g., >450,000 participants in depression (Cross-Disorder Group of the Psychiatric Genomics Consortium, 2019).