Age-of-Onset Classification of Conduct Disorder: Reliability and Validity in a Prospective Cohort Study

OBJECTIVE: To test in a prospective clinical cohort study the reliability and validity of the age-of-onset subtyping of conduct disorder. METHOD: Participants were adolescents referred to psychiatric clinics who met DSM-III-R criteria for conduct disorder by structured diagnostic interview. Age of onset was the reported age of the first conduct disorder symptom. The reliability of age-of-onset report was tested by assessing agreement within …