Book excerpt: This Provider's Guide introduces a comprehensive and developmentally appropriate treatment program,, Pathways for Self-Discovery and Change (PSDC), which provides the specific tools necessary for improving evaluation and treatment of at-risk youth, a particularly vulnerable patient population in the justice system. Using an adolescent-focused format, this protocol identifies psychological, biological, and social factors that contribute to the onset of adolescent deviance, and establishes guidelines for delivery of a 32-session treatment curriculum designed to rehabilitate both male and female adolescents with co-occurring substance abuse and criminal conduct. Now in its Second Edition, this guide provides treatment practitioners, program evaluators, and youth services administrators with the most up to date, comprehensive, and accessible information for the treatment and rehabilitation of juvenile justice clients. It is built on theoretical and research advances in the treatment and rehabilitation of juvenile justice clients, as well as feedback over the past seven years from PSDC counselees, treatment providers, and program administrators.