GRM5 and attention deficit-hyperactivity disorder: We identified novel differentially expressed genes (PRKAG2, MAPK1), and genes with known associations to either ADHD or ND (ANK3, CALD1, CHRNA4, CHRNA7, CMTM8, DLG4, DUSP6, GNG3, GNG11, GRIK5, GRINA2, GRM5, ICAM2, KCNJ6, PRKAB1, SNAP25, SYNPO, SYT1, VAMP2).