MST is a pragmatic and goal-oriented treatment that specifically targets those factors in each youth’s ecology that are contributing to his or her antisocial behaviour.

MST interventions typically aim to:

• improve caregiver discipline practices
• enhance family affective relations
• decrease youth association with antisocial peers
• increase youth association with pro social peers
• improve youth school or vocational performance
• engage youth in pro social recreational outlets
• develop an informal support network to help caregivers achieve and maintain such changes.

Specific treatment techniques used to facilitate these gains are integrated from those therapies that have the most empirical support, including cognitive behavioural, behavioural, and pragmatic family therapies.

The design and implementation of MST interventions is based on nine core principles of MST - see Treatment Principles. These principles serve to operationalise MST, and evaluations of treatment fidelity are based on participants’ (i.e., parent, therapist) ratings of therapists’ and supervisors’ adherence to these principles.

MST is delivered in the natural environment (e.g., home, school, community). The treatment plan is designed in collaboration with family members and is, therefore, family driven rather than therapist driven.

The therapist is responsible for engagement with the family and with other key participants in the youth’s ecology (e.g. teachers, school administrators, community members, workers from agencies with mandated involvement). Similarly, the therapist and provider agency are held accountable for achieving change and for positive case outcomes.

Therapeutic contacts emphasize the positive and use strengths as levers for change. Interventions always target specific, well-defined problems and are present-focused and action-oriented.

Therapeutic efforts focus on requiring daily or weekly effort by family members that result in observable and measurable behaviour change. The effectiveness of these therapeutic efforts is evaluated continuously from multiple perspectives (e.g. care givers, identified youth, school teachers, supervisor, MST consultant).