Evidence for developmentally based diagnoses of oppositional defiant disorder and conduct disorder.

This paper compares the validity of DSM-III-R diagnoses of oppositional defiant disorder (ODD) and conduct disorder (CD) and an alternative option which is subdivided into three levels according to developmental sequence and severity: modified oppositional disorder (MODD), intermediate CD (ICD), and advanced CD (ACD). Using a sample of 177 boys followed over 3 years, both the DSM-III-R and the alternative diagnostic constructs are evaluated on three criteria: symptom discriminative validity, and diagnostic external and predictive validity. Most DSM-III-R ODD and CD symptoms discriminated between ODD and CD, but exceptions are noted. Additional analyses demonstrated considerable overlap among DSM-III-R oppositional symptoms. The majority of the symptoms proposed for the alternative option could be assigned to a specific level based on acceptable symptom discrimination. External validity lent support to the distinctions between DSM-III-R ODD and CD, and between MODD, ICD, and ACD. MODD was a better predictor than ODD of which MODD, ICD, and ACD. MODD was a better predictor than ODD of which boys received a later diagnosis of CD. Suggestions are made for the inclusion and exclusion of symptoms for developmentally based diagnoses of oppositional and conduct disorders.