title: A principal components analysis of the Autism Diagnostic Interview-Revised.
abstract: OBJECTIVE
  To develop factors based on the Autism Diagnostic Interview-Revised (ADI-R) that index separate components of the autism phenotype that are genetically relevant and validated against standard measures of the constructs.
  
  
  METHODS
  ADIs and ADI-Rs of 292 individuals with autism were subjected to a principal components analysis using VARCLUS. The resulting variable clusters were validated against standard measures.
  
  
  RESULTS
  Six clusters of variables emerged: spoken language, social intent, compulsions, developmental milestones, savant skills and sensory aversions. Five of the factors were significantly correlated with the validating measures and had good internal consistency, face validity, and discriminant and construct validity. Most intraclass correlations between siblings were adequate for use in genetic studies.
  
  
  CONCLUSIONS
  The ADI-R contains correlated clusters of variables that are valid, genetically relevant, and that can be used in a variety of studies.
authors.affiliation: Department of Psychiatry, Tufts New England Medical Center, Boston, MA, USA.
authors.forename: Ovsanna
authors.initials: O
authors.lastname: Tadevosyan-Leyfer
authors.forename: Michael
authors.initials: M
authors.lastname: Dowd
authors.forename: Raymond
authors.initials: R
authors.lastname: Mankoski
authors.forename: Brian
authors.initials: B
authors.lastname: Winklosky
authors.forename: Sara
authors.initials: S
authors.lastname: Putnam
authors.forename: Lauren
authors.initials: L
authors.lastname: McGrath
authors.forename: Helen
authors.initials: H
authors.lastname: Tager-Flusberg
authors.forename: Susan E
authors.initials: SE
authors.lastname: Folstein
mesh_terms: D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000175:diagnosis* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D010641:Phenotype; D015203:Reproducibility of Results