Like the extant literature of genome-wide association studies of ADHD, the current study represents an intermediate step towards understanding genetic influences on the disorder. 28 If it is true that ADHD is influenced by many common gene variants with small individual effects, then much larger genome-wide association studies need to be conducted. We and our colleagues in the Psychiatric GWAS Consortium 29 PGC2009, are working to pool together GWAS samples for ADHD and other disorders in the belief that pooled analyses of very large data sets will be needed to identify genes for ADHD and its associated impairments.
