Noting that almost 150,000 adolescents in the United States sought treatment for substance abuse problems in 1998, the authors maintain that the CYT study was funded as the first multi-site randomized field trial conducted with adolescent substance abusers in order to test the validity of a new series of treatment approaches. Describing the five manual-guided treatment models tested by this research, the bulk of this article details 6-week intervention programs of motivational enhancement therapy (MET); 12-week intervention programs of MET and cognitive behavior therapies (CBT); 12-week intervention programs of MET, CBT, and a family support network (FSN); 12-week intervention programs based on the adolescent community reinforcement approach (ACRA); and a multi-dimensional family therapy (MDFT) approach. After describing the treatment background, empirical support, theoretical underpinnings, goals, treatment mechanisms, and structure and content of each of the five treatment model’s approaches, the authors discuss procedures used in the CYT study for maintaining treatment fidelity and for monitoring quality assurance. The authors maintain that these five manual-guided treatment models have tremendous potential to advance treatment and research for all adolescents with substance abuse disorders. References