Abstract
This study explores the factor structure of behaviours that correspond to symptoms of DSM-III-R oppositional defiant (OD) and conduct disorder (CD). It also seeks to clarify how those hypothetical factors may relate to diagnoses of OD and CD. Using exploratory factor analysis and cluster analysis of parent questionnaire data from group of referred adolescents (N=528) diagnosed according to DSM-III criteria the authors extracted four factors. One of them corresponded closely to DSM-III-R OD, while the others comprised different aspects of the CD construct. The findings suggest there are subtypes of conduct problems in adolescents, and give some support to the distinction between conduct and oppositional disorders.