Psychoanalysis Unit


Services for Teens Engaging in Problematic Sexual Behaviour (STEPS-B)


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The STEPS-B trial was a feasibility study of Multisystemic Therapy for Problem Sexual

Behaviour (MST-PSB) in the UK. Forty young people and their carers were recruited into the trial, with half of the families allocated to MST and the other half to management at usual. Families were followed up at 8, 14, and 20 months after beginning of treatment, for assessment of out-of-home placement, offending behaviour, young person mental health and behaviour, family functioning, and parental involvement. Families in the MST arm also took part in optional qualitative interviews about their experiences with the programme.

What is Multisystemic Therapy?

Multisystemic Therapy (MST) is an intervention specifically designed for young people who exhibit antisocial behaviour, and their families. The programme was original developed in the United States to help young people who were at higher risk of becoming young offenders. The strength of MST is in integrating different elements of treatment (such as cognitive-behavioural therapy and family therapy), and focusing on different aspects of the young person's environment, such as home life, school, friends, and the community.

An adaptation of the programme, Multisystemic Therapy for Problem Sexual Behaviour (MST-PSB), was designed specifically to help young people who engage in problematic sexual behaviours. In addition to the help provided as part of MST, MST-PSB therapists help the family address any denial about the offense that occurred, address safety planning to reduce the young person's access to potential victims, and encourage age-appropriate and healthy relationships with peers.

For more information about MST-PSB, see: http://mstservices.com/target-populations/problem-sexual-behavior

What is STEPS-B?

Although there is already research addressing the effectiveness of MST-PSB in the US, it had not yet been assessed in a UK context. The Services for Teens Engaging in Problematic Sexual Behaviour (STEPS-B) trial was designed as a feasibility study of MST-PSB. The primary outcome of the study was to determine whether MST-PSB could contribute to fewer young people being placed in residential care, primarily due to problem sexual behaviour. Secondary outcomes included reducing offending, reducing problem sexual behaviour, improved educational outcomes, and improved family functioning.

Who took part in the research?

In total, 40 young people and 40 carers agreed to take part in the study. The young people were between 10 and 18 years old (13.4 years old on average) and 36 (90%) of the participants were male. 21 families received Multisystemic Therapy (MST) and 19 received Management As Usual ("MAU" - which is the help families would normally get before MST was available).

How was data collected?

The research team met with the families at the beginning of the treatment, and 8, 14, and 20 months later. Participants completed a packet of questionnaires which asked about problematic sexual behaviour, different mental health problems, emotions and behaviour, quality of relationships, parenting skills, and parental mental health.


What were the findings?

A full report on the results of the study can be found here: https://www.gov.uk/government/publications/multisystemic-therapy-for-adolescent-problematic-sexual-behaviour

  • Young people in both groups had fewer cautions and convictions for sexual offences after the treatment (MST group: from an average of 10 cautions/convictions prior to treatment to 0 post-treatment. In the MAU group: from 18 to 1).
  • There have been more positive improvements in the MST group, compared to MAU in in how much parents were involved in their children's lives, and how well the family as a whole worked together.
  • Families who received MST were invited to take part in an optional interview. This became a great way to better understand their experience of receiving the intervention. These interviews revealed that:
  1. Young people had strong feelings of embarrassment, shame, and fear of stigma with regards to the behaviour which led to their involvement in MST.
  2. The families felt they had a good relationship with the MST therapist, who has helped young people understand their problematic behaviour and taught them skills to manage the behaviour in the future. Parents thought that a positive relationship with the therapist helped them understand their child's behaviour better, and repair their relationship.
  3. After finishing MST, parents felt that the programme has helped them, but had mixed feelings about the future, including residual feelings of guilt, and dealing with ongoing problems.
  • Therapists and other staff said in the interviews that they felt positively about MST-PSB, but were realistic about its shortcomings. For example, they were concerned whether this type of therapy is well suited to all young people referred for PSB, or if some families would also need extra help.

What do we recommend?

As requested by the Department for Education, the research team made several recommendations for the future of the MST-PSB programme, based on the findings from the study.

  • There is a need for some changes - some families need extra help and attention for other complex problems they have, such as additional support for young people showing trauma as a result of prior sexual abuse
  • MST-PSB teams should work together along with Local Authorities to provide a better care for families in need
  • An improved system should be put in place to find young people who display problematic sexual behaviour, so that they can get the help they need.
  • MST-PSB teams might need to do more research to have a better understanding of young people with these problems and difficulties they experience


This research study was funded by the Department for Education.

Trial team

Professor Peter Fonagy

Dr Stephen Butler

Dr Michael Seto

Dr Alisa Anokhina

Andrew Baly

Rachel Ellison

Karolina Kaminska

Useful links

MST-UK website: http://www.mstuk.org/

MST-PSB in the US: http://mstservices.com/target-populations/problem-sexual-behavior

Brandon Centre page on MST-PSB: http://brandon-centre.org.uk/multisystemic/what-is-multisystemic-therapy-for-problem-sexual-behaviour-mst-psb/

Published report: https://www.gov.uk/government/publications/multisystemic-therapy-for-adolescent-problematic-sexual-behaviour