A contingency management intervention to reduce cannabis use and time to relapse in early psychosis: the CIRCLE RCT

Abstract

Background Cannabis is the most prevalent illicit substance among people with psychosis, and its use is associated with poorer clinical and social outcomes. However, so far, there has been limited evidence that any treatment is effective for reducing use. Contingency management (CM) is an incentive-based intervention for substance misuse that has a substantial evidence base across a range of substances and cohorts. However, to date there have been no randomised controlled trials (RCTs) of CM as a treatment for cannabis use specifically in psychosis. Objective To conduct a RCT investigating the clinical effectiveness and cost-effectiveness of CM in reducing cannabis use among Early Intervention in Psychosis (EIP) service users. Design The CIRCLE (Contingency Intervention for Reduction of Cannabis in Early Psychosis) trial was a rater-blinded, multicentre RCT with two arms. Participants were randomised 1 : 1 to either an CM arm, in which participants received CM for cannabis use alongside an optimised treatment-as-usual programme including structured psychoeducation, or a control arm in which participants received the treatment as usual only. Setting EIP services across the Midlands and the south-east of England. Participants The main eligibility criteria were EIP service users with a history of psychosis, aged 18–36 years, and having used cannabis at least once per week during 12 of the previous 24 weeks. Intervention The CM intervention offered financial incentives (i.e. shopping vouchers) for cannabis abstinence over 12 once-weekly sessions, confirmed using urinalysis. The maximum value in vouchers that participants could receive was £240. Main outcome measures The main outcome was time to relapse, operationalised as admission to an acute mental health service or hospital. The primary outcome was assessed at 18 months post inclusion using electronic patient records. Secondary outcomes assessed the clinical effectiveness and cost-effectiveness of the intervention, for which data were collected at 3 and 18 months. Results A total of 278 participants were randomised to the CM arm and 273 were randomised to the control arm. In total, 530 (96%) participants were followed up for the primary outcome. There was no significant difference in time to admission between trial arms by 18 months following consent (hazard ratio 1.03, 95% confidence interval 0.76 to 1.40). There were no statistically significant differences in most secondary outcomes, including cannabis use, at either follow-up assessment. There were 58 serious adverse events, comprising 52 inpatient episodes, five deaths and one arrest. Limitations Participant retention was low at 18 months, limiting the assessment of secondary outcomes. A different CM intervention design or reward level may have been effective. Conclusions The CM intervention did not appear to be effective in reducing cannabis use and acute relapse among people with early psychosis and problematic cannabis use. Future work Cannabis use is still a significant clinical concern in this population. A pressing need remains to identify suitable treatments. A wider perspective on the social circumstances of young people with psychosis may be needed for a successful intervention to be found. Trial registration Current Controlled Trials ISRCTN33576045. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 45. See the NIHR Journals Library website for further project information.

Technology-Based Psychological Interventions for Young Adults With Early Psychosis and Cannabis Use Disorder: Qualitative Study of Patient and Clinician Perspectives

“…Our results showed that the type and intensity of face-to-face psychological interventions for CUD were variable and depended on clinicians' training background, skills, and experience. Similar to previous studies, we found that structural factors (ie, lack of time and staff turnover) represent barriers to psychological interventions [13,28]. Clinicians viewed TBPIs as a useful addition to their toolbox of interventions and as a way to circumvent some of these barriers and increase the consistency of services offered in FEP clinics.…”

“…Therefore, using CM only in conjunction with other psychological interventions (eg, MI, CBT, or psychoeducation) was considered potentially beneficial in achieving long-term reductions in cannabis use. This opinion is empirically supported by recently published data from the Contingency Intervention for Reduction of Cannabis in Early Psychosis randomized controlled trial (RCT), which showed that cannabis use and abstinence rates were not statistically different between the CM and computer-based psychoeducation intervention arms at 3-and 18-month follow-ups [28,31]. Our results suggest that offering nonfinancial incentives as part of the TBPIs could be considered a strategy to increase patient engagement in the intervention, are social reinforcement techniques (eg, certificates for achieving treatment milestones), and are generally appreciated by individuals receiving interventions for SUD [32,33].…”

Barriers and Facilitators That Influence Providers’ Ability to Educate, Monitor, and Treat Substance Use in First-Episode Psychosis Programs Using the Theoretical Domains Framework

“…There is a paucity of literature examining evidence-based treatment for substance use among individuals experiencing early psychosis (Bello & Dixon, n.d.). A recent study found that contingency management did not reduce cannabis use among individuals with FEP enrolled in an early intervention program (Johnson et al, 2019; Rains et al, 2019). However, previous studies have demonstrated the effectiveness of contingency management on increasing abstinence from alcohol, tobacco, and cannabis among individuals with co-occurring substance use and serious mental illness in an array of treatment settings (Forster et al, 2019; McPherson et al, 2018; Oluwoye, Kriegel, et al, 2020).…”

Are we any closer to identifying a causal relationship between cannabis and psychosis?

“…Overall, there is limited evidence in relation to clinical interventions for cannabis psychosis, and although some are in the development stage, these tend to be focused on a specific symptom of psychosis such as thoughts rather than targeting all aspects of the condition [32,33,34]. There are encouraging signs that a cognitive based model could be used to treat those who have developed a cannabis psychosis [35].…”