There are four major points that separate MST from other treatments that address challenging behaviours in youth:

1. RESEARCH:
Proven long-term effectiveness through rigorous scientific evaluations

2. TREATMENT THEORY:
A clearly defined and empirically grounded treatment theory

3. IMPLEMENTATION:
A focus on provider accountability and adherence to the treatment model

4. FOCUS ON LONG-TERM OUTCOMES:
Empowerment of caregivers to manage future difficulties, resulting in positive treatment outcomes and significant costs savings for the larger community

RESEARCH
MST is a well-validated treatment model (Kazdin & Weisz, 1998) with eight randomised clinical trials completed and several others underway. As of 2001, over $30 million dollars have been spent conducting research on the effectiveness of MST.

Studies of hundreds of antisocial youth have shown that MST reduced long-term rates of rearrest by 25% to 70% in comparison with control groups.

Studies with long-term follow-ups showed MST reduced days in out-of-home placements by 47% to 64% in comparison with control groups.

Compared with control groups, MST studies have consistently demonstrated improved family relations and family functioning.

MST has reduced drug use in antisocial youth, in comparison with control groups.

Treatment theory
MST is detailed in a treatment manual (Henggeler, Schoenwald, Borduin, Rowland, & Cunningham, 1998) and operationalised through adherence to nine treatment principles. The treatment theory underlying MST draws upon causal modelling studies of serious antisocial behaviour and social-ecological and family systems theories of behaviour. The MST model is based on decades of research on the determinants of antisocial behaviour.

Implementation
MST places an extremely strong focus on provider accountability. The MST therapist, the MST team, and the entire host agency are responsible for removing barriers to service access and for achieving outcomes with every case (e.g., responsibility of the therapist to engage the family, accountability of the therapist and provider organization to achieve sustainable outcomes that the family can maintain after treatment ends).

Studies have shown that key youth outcomes (e.g., involvement with youth justice, out-of-home placement) are significantly associated with a therapist’s adherence to the MST principles (hence the emphasis on maintaining quality assurance).

In practice, MST is a very analytical yet pragmatic and task-oriented treatment. MST therapists are trained to always be aware of their understanding of each case and to always support their “hunches” with observable evidence. In order to assess the impact of an intervention, MST therapists are trained to describe the observable and measurable outcomes they are aiming for, and to document these anticipated outcomes prior to implementing the intervention. Specific treatment methodologies used as part of MST interventions are empirically based (e.g., cognitive behaviour therapies, behavioural parent training, and the pragmatic family therapies—structural family therapy, strategic family therapy, etc.).

Focus on long-term outcomes
The ultimate goal of MST is to empower the youth’s primary caregivers with the skills and resources needed to independently address the difficulties that arise in raising teenagers with behavioural problems and to empower youth to cope with family, peer, school, and neighbourhood problems.

MST focuses on changing the known determinants of offending, including characteristics of the individual youth, the family, peer relations, school functioning, and the neighbourhood. This change is accomplished through the mobilization of informal child, family, and community resources that already exist in the natural ecology.

MST treatment plans are designed in collaboration with family members and are family driven rather than therapist driven.

Cost Savings
Cost savings are achieved by targeting youths who are receiving the most costly, intensive services and helping the family to manage the youth’s behaviour successfully by promoting the family’s skills and competencies, as well as strengthening the family’s linkages with natural supports in the community.

The Washington State Institute for Public Policy (2001) concluded that MST was the most cost-effective of a wide variety of treatments designed to reduce serious antisocial behaviour by adolescents. Indeed, MST provided a net economic benefit to taxpayers of US $130,000 in decreased program and victim costs.