Assessing conduct disorder: a new measurement approach.

The Delinquent Activities Scale (DAS) was used to develop indicators of conduct disorder (CD) in terms of symptom severity and age of onset. Incarcerated adolescents (N = 190) aged 14 to 19 were asked about their delinquent behaviors, including age the behavior was first performed, as well as substance use and parental and peer influences. Assessments were performed for the 12 months prior to incarceration and at 3-month postrelease follow-up. Evidence supports the utility of the DAS as a measure of CD diagnosis, including concurrent incremental validity. Furthermore, CD severity (symptom count) was significantly associated with two peer factors: friend substance use and friend prior arrests, with medium to large effect sizes (ESs). Earlier age of CD onset was associated with earlier marijuana use. This study finds that the DAS is a useful instrument in that it is easy to apply and has adequate psychometrics.