Solutions Trial: Solution Focused Brief Therapy (SFBT) in 10–17-year-olds presenting at police custody: a randomised controlled trial

Background:
Within England, children and young people (CYP) who come into police custody are referred to Liaison and Diversion (L&D) teams. L&D teams have responsibility for liaising with healthcare and other support services while working to divert CYP away from the criminal justice system but have traditionally not provided targeted psychological interventions to CYP. Considering evidence that Solution Focused Brief Therapy (SFBT) leads to a reduction in internalising and externalising behaviour problems in CYP, the aim of this randomised controlled trial (RCT) was to determine whether there is a difference between services as usual (SAU) plus SFBT offered by trained therapists working within a L&D team, and SAU alone, in reducing offending behaviours in 10–17-year-olds presenting at police custody.

Methods:
Design: two-arm individually RCT with internal pilot and process evaluation.
Participants: N = approximately 448 CYP aged 10–17 years presenting at one of three police custody suites in the area served by Lancashire and South Cumbria NHS Foundation Trust (LSCFT) who are referred to the L&D team. Participants will be recruited and allocated to intervention:control on a 1:1 basis. Interviews will be performed with 30–40 CYP in the intervention arm, 15 CYP in the control arm, up to 20 parents/guardians across both arms, up to 15 practitioners, and up to 10 site staff responsible for screening CYP for the trial. Intervention and control: Those allocated to the intervention will be offered SAU plus SFBT, and control participants will receive SAU only.
Primary outcome: CYP frequency of offending behaviours assessed through the Self-Report Delinquency Measure (SRDM) at 12 months post-randomisation.
Secondary outcomes: criminal offence data (national police database); emotional and behavioural difficulties (self-report and parent/guardian reported); gang affiliation (self-report).
Process evaluation: evaluation of acceptability and experiences of the CYP, parents/guardians, site staff and practitioners; fidelity of SFBT delivery.

Discussion:
This two-arm individually RCT will evaluate the effectiveness of SFBT in reducing offending behaviours in CYP presenting at police custody suites within the area served by LSCFT. Our process evaluation will assess the fidelity of delivery of SFBT, the factors affecting implementation, the acceptability of SFBT in CYP aged 10–17 years and recruitment and reach. We will also examine systems and structures for future delivery, therefore assessing overall scalability. Trial registration: ClinicalTrials.gov ISRCTN14195235. Registered on June 16, 2023.