title: Alternative factor models and heritability of the Short Leyton Obsessional Inventory-Children's Version.
abstract: An alternative models framework was used to test three confirmatory factor analytic models for the Short Leyton Obsessional Inventory-Children's Version (Short LOI-CV) in a general population sample of 517 young adolescent twins (11-16 years). A one-factor model as implicit in current classification systems of Obsessive-Compulsive Disorder (OCD), a two-factor obsessions and compulsions model, and a multidimensional model corresponding to the three proposed subscales of the Short LOI-CV (labelled Obsessions/Incompleteness, Numbers/Luck and Cleanliness) were considered. The three-factor model was the only model to provide an adequate explanation of the data. Twin analyses suggested significant quantitative sex differences in heritability for both the Obsessions/Incompleteness and Numbers/Luck dimensions with these being significantly heritable in males only (heritability of 60% and 65% respectively). The correlation between the additive genetic effects for these two dimensions in males was 0.95 suggesting they largely share the same genetic risk factors.
authors.affiliation: Centre for Public Health, Department of Psychiatry, Queen's University of Belfast, Whitla Medical Building, 97Lisburn Road, Belfast, BT9 7BL, UK. jttemoore@btinternet.com
authors.forename: Janette
authors.initials: J
authors.lastname: Moore
authors.forename: Gillian W
authors.initials: GW
authors.lastname: Smith
authors.forename: Mark
authors.initials: M
authors.lastname: Shevlin
authors.forename: Francis A
authors.initials: FA
authors.lastname: O'Neill
mesh_terms: D000293:Adolescent; D002648:Child; D004200:Diseases in Twins / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008960:Models, Psychological; D015233:Models, Statistical; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D010555:Personality Inventory / Q000706:statistics & numerical data*; D010641:Phenotype; D011594:Psychometrics / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012737:Sex Factors; D012931:Social Environment