title: Validity of DSM-IV subtypes of conduct disorder based on age of onset.
abstract: OBJECTIVE
  To present data from the DSM-IV field trials that led to the distinction between subtypes of conduct disorder (CD) that emerge in childhood or adolescence. In addition, data from a household sample were used to attempt to cross-validate these findings.
  
  
  METHODS
  Differences between youths who met criteria for the two subtypes of CD were examined in the field trials sample of 440 youths aged 4 through 17 years and in a household sample of 1,285 youths aged 9 through 17 years.
  
  
  RESULTS
  In both samples, there was a steep decline in aggression occurring around an age of onset of 10 years, but the number of nonaggressive behaviors was unrelated to the age of onset of CD. In the field trials sample, youths who met criteria for the adolescent-onset type were more likely to be girls, less likely to meet criteria for oppositional defiant disorder, and less likely to have a family history of antisocial behavior than the childhood-onset type, but these latter findings were not confirmed in the household sample.
  
  
  CONCLUSIONS
  The DSM-IV approach to subtyping CD distinguishes subgroups that differ markedly in level of physical aggression. The advantages of a developmental approach to subtyping are discussed.
authors.affiliation: Department of Psychiatry, University of Chicago, IL 60637, USA.
authors.forename: B B
authors.initials: BB
authors.lastname: Lahey
authors.forename: R
authors.initials: R
authors.lastname: Loeber
authors.forename: H C
authors.initials: HC
authors.lastname: Quay
authors.forename: B
authors.initials: B
authors.lastname: Applegate
authors.forename: D
authors.initials: D
authors.lastname: Shaffer
authors.forename: I
authors.initials: I
authors.lastname: Waldman
authors.forename: E L
authors.initials: EL
authors.lastname: Hart
authors.forename: K
authors.initials: K
authors.lastname: McBurnett
authors.forename: P J
authors.initials: PJ
authors.lastname: Frick
authors.forename: P S
authors.initials: PS
authors.lastname: Jensen
authors.forename: M K
authors.initials: MK
authors.lastname: Dulcan
authors.forename: G
authors.initials: G
authors.lastname: Canino
authors.forename: H R
authors.initials: HR
authors.lastname: Bird
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D019955:Conduct Disorder / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D016018:Least-Squares Analysis; D016015:Logistic Models; D008297:Male; D008370:Manuals as Topic; D011647:Puerto Rico / Q000453:epidemiology; D015203:Reproducibility of Results; D014481:United States / Q000453:epidemiology