Multisystemic Therapy (MST)

The MST Program is an intensive, short-term intervention (3-5 months) which involves the whole family. It is a home-based and/or virtual, family-focused treatment which aims to reduce antisocial behaviour and improve family functioning, peer relations, and school performance of youth ages 12-17. Sessions are goal-focused, strength-based, and occur 2+ times a week in the youth’s natural environment.

The MST Program is an evidence-based program that was developed at the Medical University of South Carolina where its effectiveness has been well documented.

Goals of the Program:

  • To reduce out of home placement
  • To decrease youth criminal and antisocial behaviour
  • To improve family functioning

Inclusionary Criteria:

  • Youth ages 12 – 17 yrs (, who are residents of Peel
  • Youth who are residents of Peel, Dufferin, Halton for Probation Referrals
  • High-risk youth and their families/caregivers
  • Youth who are engaging in criminal and anti-social behaviour
  • Youth who are experiencing difficulties across multiple systems: individual, family, peers, school and/or community
  • Youth who are at risk of out-of-home placement

Exclusionary Criteria:

  • Youth who are living independently, or youth for whom their primary caregiver is unwilling to participate in therapy
  • Youth who are actively suicidal, homicidal or in need of crisis stabilization
  • Youth who are referred primarily as a result of the youth’s sexual offending behaviour (referring workers are encouraged to consult with the MST Program Supervisor regarding this group of youth)

Referral Sources:

  • Self-referrals
  • Community Service Providers
  • Peel CAS
  • Peel School Boards
  • Hospitals
  • Youth Justice Services

Referral Process:

Parents/caregivers can make a self-referral by contacting or by calling 905.451.4655.

Youth’s Probation Officer completes a referral form and sends referral to the AYSP Intake Specialist.

Families are also eligible for this program through the Internal Transfer Protocol via or AYSP’s Internal Referral Process, including Youth Justice clients.

The MST Program Supervisor is available to answer any questions you may have regarding the referral process or program criteria.