Multisystemic Therapy (MST)

Program snapshot

Age group: Adolescence (12-17)

Gender: Mixed (male and female)

Population served: Placed out-of-home; Youth in contact with law enforcement (and/or at risk)

Topic: Academic issues; Aggressive/violent behaviours; Antisocial/deviant behaviours

Setting: Urban area; Community-based setting; Residential/home; Social services setting

Location: Ontario; Quebec

Number of completed Canadian outcome evaluation studies: 2

Continuum of intervention: Secondary crime prevention

Brief Description

The Multisystemic Therapy (MST) program is an intensive family- and community-based treatment intervention that focuses on working with families in the settings in which the problem behaviours occur (e.g., home, school, community) rather than with individual youth in detention centres or other residential settings outside of their own families. The program focuses on the social ecology of at-risk youth, engaging both the youth and their families in order to decrease risk factors and increase protective factors with regards to family relationships, peers, school, and community.


The main goals of the MST program are to:

  • Decrease rates of antisocial behaviour (violence and delinquency) and other clinical problems and increase school performance/attendance;
  • Improve parental discipline procedures, and family relations; and
  • Develop a support network for the youth that includes extended family, neighbours, and friends.


The appropriate clientele for the MST program is youth aged 12 to 17 years old who are at risk of out-of-home placement due to violent or delinquent behaviours, have academic difficulties and/or are expelled or have dropped out of school, have substance abuse issues (in the context of the other risk factors present), and/or are involved with the youth justice system.

Potential participants are referred primarily by schools, children’s aid, and other youth organizations. Inappropriate referrals to the MST program include youth referred for primarily psychiatric behaviours (i.e., actively suicidal, actively homicidal, actively psychotic), youth referred primarily for sex offences (in the absence of other antisocial/delinquent behaviours), and youth with pervasive developmental delays.

Core Components

The MST program is an intensive, short-term intervention of three to five months, providing approximately 60 hours of individualized treatment for each participating youth.

A treatment plan is designed in collaboration with family members. The MST therapists work closely with the youth’s family in order to build a network of support that is enduring, realistic, and able to sustain the changes made during the program, and to develop strategies to promote and monitor the youth’s success at home, at school, and in the community. The sessions occur at least twice a week and take place in the youth’s natural environment, typically their home.

The MST program has 9 different principles which serve as the core program elements. These principles are:

  • Principle 1: Finding the Fit
  • Principle 2: Focusing on Positives and Strengths
  • Principle 3: Increasing Responsibility
  • Principle 4: Present Focused, Action Oriented and Well Defined
  • Principle 5: Targeting Sequences
  • Principle 6: Developmentally Appropriate
  • Principle 7: Continuous Effort
  • Principle 8: Evaluation and Accountability
  • Principle 9: Generalization

Implementation Information

Some of the critical elements for the implementation of this program or initiative include the following:

  • Organizational requirements: In addition to being familiar with the kind of therapy MST utilizes and agreeing to hire the type of therapists MST requires, the lead organization should have a case record keeping system, staff knowledgeable about issues such as confidentiality, and relations with formal community resources that support the provision of community-based mental health services. The lead organization must enter into a MST licensing agreement with MST Services Inc.
  • Partnerships: The development of a MST program is a process that requires significant community collaboration and often takes up to 12 months to compete.
  • Training and technical assistance: Training and consultation services are provided to licensed MST sites by MST Services Inc.
  • Risk assessment tools: Child and Adolescent Assessment Scale (CAFAS) screening tool
  • Materials & resources: The MST program must have a 24 hour/day, 7 day/week on-call system to provide coverage of services when needed and to respond to crises. MST Services Inc. created the MST Program Development Method (PDM) to assist with implementation of the MST program. The two treatment manuals are available for purchase; all other MST materials are provided to licensed MST sites.

International Endorsements

The most recognized classification systems of evidence-based crime prevention programs have classified this program or initiative as follows:

  • Blueprints for Healthy Youth Development: Model
  • Crime Solutions/OJJDP Model Program Guide: Effective (more than one study)
  • SAMHSA's National Registry of Evidence-based Programs and Practices: 2.9 - 3.2
  • Coalition for Evidence-Based Policy: Not applicable.

Gathering Canadian Knowledge

Canadian Implementation Sites

The following organizations have been supported by Public Safety Canada’s National Crime Prevention Strategy to implement the MST program:

  • Gangbusters Multisystemic Therapy (MST) Project (Agincourt Community Services Association) (Ontario) (2009-2014) (outcome evaluation completed; see study #2)
  • Youth Connections MST Program (John Howard Society of Durham) (Ontario) (2011-2014) (only process evaluation completed)

In addition, several other organizations in Ontario currently have full licences for MST; for examples: Associated Youth Services of Peel, Children’s Mental Health of Leeds & Grenville, Kinark Child and Family Services, and the Youth Services Bureau of Ottawa.

Main Findings from Canadian Outcome Evaluation Studies

Study 1

A multisite outcome evaluation study of the MST program was conducted between 1997 and 2001 by Leschied and Cunningham (2002). A randomized control trial of MST was conducted in four southern Ontario communities (London, Mississauga, Simcoe County and Ottawa).

Results from this evaluation showed the following:

  • No treatment effect of the program on offending behaviour could be identified. The final results of the study showed no statistically significant differences between program participants and non-participants in terms of key criminal justice outcomes, such as the number of convictions and days in custody; and
  • This leads to four potential conclusions: the treatment effect of MST in Ontario is too small to be detected statistically with a sample of 409, or there is no treatment effect of MST that exceeds that of usual services in Ontario, or neither MST nor the usual services were effective when criminal convictions are the outcome variable, or MST might be effective in Canada under different conditions of implementation, with different clients, different outcome measures, and/or compared with different services.

For more information, refer to Leschied & Cunningham’s (2002) publication.

Study 2

As part of Public Safety Canada’s funding, an outcome evaluation studyFootnote1 of the MST program was conducted between 2009 and 2014 by Harry Cummings and Associates Inc. Originally, program effects were to be assessed using a repeated measures ‘delayed treatment’ design in which program participants in Scarborough, Ontario would be compared with an eligible group of youth waiting to receive MST services. Due to some unforeseen challenges, the youth who did not complete the program were used as the comparison group.

Results from this evaluation showed the following:

  • Over 80% of the 48 program completers experienced a drop of 20 points or more on the Child and Adolescent Functional Assessment Scale (CAFAS) between baseline and their time of discharge, which is considered to be a clinically significant improvement. As for the 9 non-completers, approximately 33% showed a similar drop in CAFAS points.
  • Three months after intake, more youth who graduated from the program than non-completers were: living at home, attending school, in vocational training or employed 20+ hours/week, and not arrested for an offence committed during MST.
  • At discharge, 75% of youth who graduated from the program were involved with prosocial peers and activities, compared to 29% of those who did not complete the program.

For more information, refer to the National Crime Prevention Centre’s (2013, 2015) publications.

Cost Information

In 2014, as part of Harry Cummings and Associates Inc.’s outcome evaluation study, it was found that the average treatment cost per youth involved in the MST program was between $22,973 (CAD) for youth accepted into the program and $31,297 (CAD) for youth that completed the program.

In 2002, Leschied & Cunningham did a cost-benefit analysis on MST. At that time, MST was provided in Ontario in four communities: London, Mississauga, Ottawa and Simcoe County. Across the four sites, and examining only custody (open and closed) costs, an economic analysis revealed that at 6 months, there were savings of $787 (CAD) per youth between the treatment and usual-services groups, before taking into account the cost of the intervention. At 12 months, the net savings had increased to $3,423 (CAD) per youth, and at 24 months, it was $3,118 (CAD). However, the intervention itself cost at least $6,000 (CAD), which meant that for the most part, the net value was negative (Leschied & Cunningham, 2002).  


Harry Cummings and Associates Inc. (2014). Evaluation of the Multisystemic Therapy Program, Toronto, Ontario. Final Evaluation Report. Submitted to the National Crime Prevention Centre, Public Safety Canada (Unpublished report).

Leschied, A., & Cunningham, A. (2002). Seeking Effective Interventions for Serious Young Offenders: Interim Results of a Four-Year Randomized Study of Multisystemic Therapy in Ontario, Canada. London, ON: Centre for Children and Families in the Justice System. Available from:

National Crime Prevention Centre. (2013). Results from the Multisystemic Therapy Program. Evaluation Summary. Ottawa, ON: Public Safety Canada. Available from:

National Crime Prevention Centre. (2015). Results from the Multisystemic Therapy Program. Evaluation Summary. Ottawa, ON: Public Safety Canada.  Available from:

For more information on this program, contact:

MST Services Inc.
710 J. Dodds Boulevard, Suite 200
Mount Pleasant, South Carolina 29464
Telephone: (843) 856-8226

Record Entry Date - 2018-02-28
Record Updated On - 2018-04-23
  1. 1

    A process evaluation study of the program was also conducted through Public Safety Canada’s funding. For more information, communicate with the Research Division, Public Safety Canada.

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