European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
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Eur Neuropsychopharmacol · Jun 2013
Shared and unique genetic contributions to attention deficit/hyperactivity disorder and substance use disorders: a pilot study of six candidate genes.
The shared genetic basis of attention deficit/hyperactivity disorder (ADHD) and substance use disorders (SUDs) was explored by investigating the association of candidate risk factors in neurotransmitter genes with both disorders. One hundred seven methadone maintenance treatment patients, 36 having an ADHD diagnosis, 176 adult patients with ADHD without SUDs, and 500 healthy controls were genotyped for variants in the DRD4 (exon 3 VNTR), DRD5 (upstream VNTR), HTR1B (rs6296), DBH (rs2519152), COMT (rs4680; Val158Met), and OPRM1 (rs1799971; 118A>G) genes. Association with disease was tested using logistic regression models. ⋯ The present study strengthens the evidence for a shared genetic basis for ADHD and addiction. The association of OPRM1 with the ADHD and SUD combination could help to explain the contradictory results of previous studies. The power limitations of the study restrict the significance of these findings: replication in larger samples is warranted.