In this proposed randomized trial, a one-way design (MI/CBT vs RT/TU) will be used to determine whether MI/CBT enhances group therapy participation and reduces substance use and related problems (such as crime, injuries and unprotected sex) post discharge in substance-involved juvenile delinquents. RT/TU is based on the 12-step model and includes psycho-educational components. Participant are followed during incarceration and for 6 months post incarceration. Primary outcome variables include alcohol and marijuana use, as well as related behaviors (illegal activities, sex or injuries while drunk or high). It is hypothesized that in comparison to teens in RT/TU, youth receiving MI/CBT will participate more in therapy (according to teen, facility staff, and counselor ratings) and will show lower levels of substance use and related problems after discharge.