The goal of MST is to provide an integrative, cost- effective, family-based treatment that results in positive outcomes for adolescents who manifest serious antisocial behavior. MST focuses first on improving psycho-social functioning for youth and their families so that the need for out-of-home child placements is reduced or eliminated. To achieve this task, MST addresses the known causes of delinquency on an individualized, yet comprehensive basis. MST interventions focus on the individual youth and his or her family, peer context, school/vocational performance, and neighborhood/community supports. Family interventions often promote the parent's capacity to monitor and discipline the adolescent. MST counselors determine the barriers to effective parental discipline and intervene accordingly. Commonly observed barriers include parental drug abuse, psychiatric conditions, and low social support. The central thrust of MST peer interventions is to remove offenders from deviant peer groups and facilitate their development of friendships with pro-social peers, with the parent being the key to achieving such goals. School and vocational interventions seek to enhance the youth's capacity for future employment, satisfaction, and financial success. A review of the application of MST in Simpsonville, S.C., shows that MST was more effective than usual services at reducing long-term rates of criminal behavior and was also less costly.