TTC12 and attention deficit-hyperactivity disorder: In order to contrast the main hypothesis of the manuscript, i.e., the existence of a network of genes underlying these complex phenotypes, we performed a formal network analysis with the LPHN3, NCAM1, TTC12, ANKK1, DRD2, and CDH13 genes, a set of significantly replicated genes either associated and/or linked to ADHD, disruptive behaviors, and SUD (Table 1).