Youth involved in the juvenile justice system have multiple problems, including an earlier onset of alcohol and drug use and higher rates of alcohol and drug use than their peers in the general population. This 4.5 year study will develop and evaluate a new group intervention for youth who have committed a first time alcohol or drug offense. Teens will be randomized to receive either usual care or the new group intervention. Teens will complete a baseline, post-test (when they complete the intervention, which could vary for each teen but is typically around 6-8 weeks), and a 3-month follow-up survey upon completion of the intervention. The investigators will examine outcomes for a variety of behaviors, including alcohol and drug use and assess whether there are differences between the teens who received usual care and the teens who received the new group intervention.