Research PapersDopamine system genes and attention deficit hyperactivity disorder: a meta-analysisMaher, Brion S.a d; Marazita, Mary L.a b c d; Ferrell, Robert E.b d; Vanyukov, Michael M.b c d eAuthor Information aDivision of Oral Biology, School of Dental Medicine bDepartment of Human Genetics, Graduate School of Public Health cDepartment of Psychiatry, School of Medicine dCenter for Education and Drug Abuse Research eDepartment of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania, USA Correspondence to Brion Maher, Ph.D., School of Dental Medicine, University of Pittsburgh, Suite 693A Salk Hall, 3501 Terrace Street, Pittsburgh, PA 15261, USA. E-mail: [email protected] Received 10 October 2001; accepted 2 May 2002 Psychiatric Genetics: December 2002 - Volume 12 - Issue 4 - p 207-215 Buy Abstract The dopamine system may play a major role in the development of attention deficit hyperactivity disorder (ADHD). We applied a random-effects model meta-analysis to family-based studies of association between ADHD and the dopamine system genes DRD4, DRD5 and DAT1. A statistical test of heterogeneity was conducted for each group of studies. The meta-analysis of DRD4 included data from 13 studies, with a total of 571 informative meioses. The pooled odds ratio estimate was 1.41 (95% CI 1.20–1.64, P=1.57×10−5), demonstrating positive association. For DRD5, data from five studies, with a total of 340 informative meioses, were combined yielding a pooled odds ratio of 1.57 (95% CI 1.25–1.96, P=8.28×10−5). Eleven studies examining DAT1, with a total of 824 informative meioses, yielded a non-significant pooled odds ratio estimate of 1.27 (95% CI 0.99–1.63, P=0.06). There was no support of heterogeneity between the studies. Overall, the meta-analyses support the involvement of the dopamine system genes in ADHD liability variation and suggest the need for studies examining interactions between these genes. © 2002 Lippincott Williams & Wilkins, Inc.