Association of the catechol-O-methyltransferase gene and attention deficit hyperactivity disorder: results from an epidemiological study of adolescents of Mexico City.

The etiology of attention deficit hyperactivity disorder (ADHD) is complex and multifactorial, with an important genetics load. Pharmacological, animal, and brain image studies provide significant evidence that monoamine genes are relevant (Gizer et al., 2009). We aimed to explore the possible association between Val158Met COMT, VNTR 30 UTR SLC6A, and LPR SLC6A4 candidate genes with ADHD and its subtypes.