title: Genetic effects on ADHD symptomatology in 7- to 13-year-old twins: results from a telephone survey.
abstract: The magnitude of genetic and environmental factors and the influence of contrast effects on attention-deficit hyperactivity disorder (ADHD) symptomatology were examined on a sample of 900 twin pairs, aged 7-13, participating in the Virginia Twin Study of Adolescent Behavioral Development (VTSABD). In addition, the genetic and environmental correlations between ADHD and oppositional-defiant disorder/conduct disorder (ODD/CD) symptomatology were estimated. A series of structural models was applied to maternal ratings from a telephone survey, designed to screen for the three dimensions of ADHD symptomatology (hyperactivity, impulsivity, and inattention) and ODD/CD symptomatology. Model-fitting results suggested that ADHD symptomatology is highly heritable and influenced mostly by additive genetic, specific environmental, and contrast effects. However, this analysis could not exclude with statistical significance additional effects from dominance. The results of the best-fitting bivariate model suggested that the genetic correlation between the two traits is 50% and replicated previous findings of a common genetic factor influencing the comorbidity of ADHD and ODD/CD symptomatologies.
authors.affiliation: Virginia Institute for Psychiatric and Behavioral Genetics, Department of Human Genetics, Virginia Commonwealth University, Richmond 23298-0003, USA. TNADDER@gems.vcu.edu
authors.forename: T S
authors.initials: TS
authors.lastname: Nadder
authors.forename: J L
authors.initials: JL
authors.lastname: Silberg
authors.forename: L J
authors.initials: LJ
authors.lastname: Eaves
authors.forename: H H
authors.initials: HH
authors.lastname: Maes
authors.forename: J M
authors.initials: JM
authors.lastname: Meyer
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology / Q000235:genetics*; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000453:epidemiology / Q000235:genetics; D002648:Child; D015897:Comorbidity; D004200:Diseases in Twins / Q000235:genetics*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008957:Models, Genetic; D010641:Phenotype; D012307:Risk Factors; D012931:Social Environment; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics; D014768:Virginia / Q000453:epidemiology