Multisystemic Therapy^® (MST^®) is an intensive family- and community-based treatment that addresses the multiple causes of serious antisocial behavior in juvenile offenders. The MST program seeks to improve the real-world functioning of youth by changing their natural settings – home, school, and neighborhood – in ways that promote prosocial behavior while decreasing antisocial behavior. Therapists work with youth and their families to address the known causes of delinquency on an individualized, yet comprehensive basis. By using the strengths in each system (family, peers, school, and neighborhood) to facilitate change, MST addresses the multiple factors known to be related to delinquency across the key systems within which youth are embedded. The extent of treatment varies by family according to clinical need. Therapists generally spend more time with families in the initial weeks (daily if needed) and gradually taper their time (to as infrequently as once a week) over the 3- to 5-month course of treatment.