title: Modeling genetic and environmental influences in the etiology of conduct disorder: a study of 2,682 adult twin pairs.
abstract: The etiology of conduct disorder (CD) was examined retrospectively in a sample of 2,682 male, female, and unlike-sex adult twin pairs from the community-based Australian Twin Register. Model-fitting analyses indicated a substantial genetic influence on risk for CD, accounting for 71% of the variance (95% confidence interval [CI] = 32-79%). There was not a statistically significant effect of the shared environment in the best-fitting model of CD, but a modest effect of the shared environment on the risk for CD could not be rejected (95% CI = 0-32%). The magnitude of genetic and environmental influences for CD liability did not vary significantly for boys and girls, and the specific genetic and environmental mechanisms important for the development of CD appeared to be largely the same for both sexes. The fit of a multiple-threshold model raises the possibility that CD may not necessarily be a discrete entity but rather an extreme of the normal variation in conduct-disordered behavior found in the general population.
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri 63110-1093, USA. wendy@wupsych1.wuStL.edu
authors.forename: W S
authors.initials: WS
authors.lastname: Slutske
authors.forename: A C
authors.initials: AC
authors.lastname: Heath
authors.forename: S H
authors.initials: SH
authors.lastname: Dinwiddie
authors.forename: P A
authors.initials: PA
authors.lastname: Madden
authors.forename: K K
authors.initials: KK
authors.lastname: Bucholz
authors.forename: M P
authors.initials: MP
authors.lastname: Dunne
authors.forename: D J
authors.initials: DJ
authors.lastname: Statham
authors.forename: N G
authors.initials: NG
authors.lastname: Martin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000987:Antisocial Personality Disorder / Q000235:genetics / Q000523:psychology; D002648:Child; D002653:Child Behavior Disorders / Q000235:genetics* / Q000523:psychology; D004200:Diseases in Twins / Q000235:genetics* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008957:Models, Genetic; D012189:Retrospective Studies; D012737:Sex Factors; D012931:Social Environment