Validity of DSM-IV subtypes of conduct disorder based on age of onset

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. Method: 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.