Behaviour change interventions to reduce risky substance use and improve mental health in children in care: the SOLID three-arm feasibility RCT

Background: Looked-after children and care leavers (henceforth children in care) are young people placed under the care of local authorities, often because of a history of family abuse and/or neglect. These young people have significantly increased risk of substance use and mental health problems compared with peers. Aim: The Supporting Looked After Children and Care Leavers In Decreasing Drugs, and alcohol (SOLID) trial aimed to investigate the feasibility of a definitive randomised controlled trial comparing two behaviour change interventions to reduce risky substance use (illicit drugs and alcohol) in and improve the mental health of children in care aged 12–20 years. Methods: The study consisted of two phases: (1) a formative phase that adapted the motivational enhancement therapy and social behaviour and network therapy interventions for use with children in care and (2) a three-arm pilot randomised controlled trial (comparing motivational enhancement therapy, social behaviour and network therapy and usual care), and a linked process and economic (return on investment) evaluation. Trial feasibility was compared with prespecified STOP/GO criteria. Setting: Six local authority areas in the north-east of England. Participants: Children in care (aged 12–20 years) who screened positive for drug and/or alcohol use within the last 12 months were eligible for the trial. The formative and process evaluations included children in care, carers, social workers, and drug and alcohol workers. Outcome measures: The primary outcomes were recruitment and retention rates at 12 months’ follow-up. Baseline and 12-month follow-up questionnaires measured self-reported drug and alcohol use, mental health and health-related quality of life. The process evaluation considered acceptability and engagement with the interventions and trial procedures. Results: Formative findings (n = 65) highlighted the need for interventions to increase the emphasis on therapeutic relationships, use creative methods of engagement and support the identification of treatment goals wider than substance misuse. Within the randomised controlled trial, of 860 participants screened, 211 (24.5%) met the inclusion criteria. One hundred and twelve (53%) of the 211 eligible children were recruited and randomised. Just 15 of the 76 (20%) participants allocated to intervention attended any of the motivational enhancement therapy of social behaviour and network therapy sessions, and 60 (54%) participants comp