Title: Randomised controlled trial of the clinical and cost-effectiveness of a contingency management intervention for reduction of cannabis use and of relapse in early psychosis
Funder: Department of Health and Social Care

Abstract: Our aim is to establish whether an intervention based on contingency management for cannabis use in early psychosis is effective in increasing time to relapse in young people with early psychosis and problematic cannabis use. We will begin by conducting a feasibility pilot study, testing the feasibility and acceptability of the intervention and whether satisfactory numbers can be recruited. We will aim to recruit 68 participants from 3 early intervention services over a 6 month period. If the targets of the pilot study are met, we will recruit further participants in 12 services to complete a full randomised controlled trial. Participants will be randomly allocated to either the experimental condition, involving contingency management combined with a psychoeducational package, or the control condition, involving psychoeducation only. Outcomes will be assessed 3 months after the beginning of the intervention and 18 months afterwards. We will also assess costs associated with being in each arm of the trial.

Lay abstract: Drug use increases the problems that people with severe mental health problems face, for example by making them more likely to relapse or to commit crimes and less likely to work. Their reliance on welfare benefits and frequent use of expensive services such as hospitals create an economic burden. Early intervention services (EISs) aim to improve prognosis for young people with early psychosis, reducing relapse and promoting attainment of social goals such as getting back to employment or education. Almost half the young people on EIS caseloads use cannabis, making this a very important impediment to recovery. It has proved very difficult to design interventions that modify substance use among people with psychosis. Because of this, we propose to adopt a new approach that is increasingly advocated in the substance misuse field as having a strong evidence base. This new approach is called Contingency Management (CM), and involves rewarding positive behaviours: here this will mean giving vouchers for use in a local shop as rewards for attending appointments and for giving cannabis free urines. In our study, we will let chance decide whether willing participants enter a group who are offered CM or a comparison group who do not receive it. Both groups will receive educational sessions from their care coordinators intended to ensure they are aware of risks and benefits of continuing cannabis use. We will compare the progress of the group who receive CM with those who do not, measured by relapse, cannabis use, ability to work and function in society, and symptoms. We will also explore service users' and clinicians' experiences of using CM and factors that might underlie any changes we observe. We will begin with a smaller scale pilot study in 3 services to establish whether enough participants can be recruited for this study and whether it is feasible to deliver the study treatment as planned. If targets are met in this, we will extend the study to 9 more teams so as to achieve a sample big enough to draw clear conclusions.

Research activity codes: 6.6 PSYCHOLOGICAL AND BEHAVIOURAL
Health categories: MENTAL HEALTH