Division of Psychiatry, University College London, London, UK.
Mental Health and Wellbeing, Warwick Medical School, University of Warwick, Coventry, UK.
Health Technol Assess. 2019 Aug;23(45):1-108. doi: 10.3310/hta23450.
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.
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.
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.
EIP services across the Midlands and the south-east of England.
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.
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.
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.
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.
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.
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.
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.
Current Controlled Trials ISRCTN33576045.
This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in ; Vol. 23, No. 45. See the NIHR Journals Library website for further project information.
大麻是精神病患者中最常见的非法物质，其使用与更差的临床和社会结果相关。然而，到目前为止，还没有证据表明任何治疗方法对减少使用都有效。条件管理（CM）是一种基于激励的物质滥用干预措施，在各种物质和队列中都有大量的证据支持。然而，迄今为止，针对精神分裂症患者的大麻使用，还没有关于 CM 作为治疗的随机对照试验（RCT）。
进行一项 RCT，以调查 CM 在减少早期精神病干预（EIP）服务使用者的大麻使用方面的临床效果和成本效益。
CIRCLE（早期精神病中减少大麻的条件干预）试验是一项盲法、多中心 RCT，分为两个组。参与者以 1：1 的比例随机分配到 CM 组或对照组。CM 组的参与者接受 CM 治疗，以减少大麻使用，同时接受优化的常规治疗方案，包括结构化心理教育，而对照组的参与者仅接受常规治疗。
英格兰中部和东南部的 EIP 服务机构。
主要的入选标准是有精神病病史的 EIP 服务使用者，年龄在 18-36 岁之间，并且在过去 24 周中有至少 12 周每周至少使用一次大麻。
CM 干预提供了财务激励（即购物券），以鼓励参与者在 12 次每周的会议中保持大麻禁欲状态，通过尿液分析来确认。参与者可以获得的购物券最高价值为 240 英镑。
主要结局是复发时间，定义为入住急性心理健康服务机构或医院。主要结局在纳入后的 18 个月使用电子病历进行评估。次要结局评估了干预的临床效果和成本效益，数据在 3 个月和 18 个月时收集。
共有 278 名参与者被随机分配到 CM 组，273 名参与者被随机分配到对照组。共有 530 名（96%）参与者在同意后 18 个月被随访主要结局。在同意后 18 个月，试验组之间的入院时间没有显著差异（风险比 1.03，95%置信区间 0.76 至 1.40）。在两个随访评估中，大麻使用等大多数次要结局均无统计学意义。共发生 58 例严重不良事件，包括 52 例住院，5 例死亡和 1 例逮捕。
18 个月时参与者的保留率较低，限制了次要结局的评估。可能需要不同的 CM 干预设计或奖励水平才能有效。
CM 干预似乎不能有效减少早期精神病和大麻使用问题患者的大麻使用和急性复发。
在这一人群中，大麻使用仍然是一个重要的临床问题。仍然需要找到合适的治疗方法。对于成功的干预措施，可能需要对年轻精神病患者的社会环境有更广泛的了解。
当前对照试验 ISRCTN33576045。
该项目由英国国家卫生研究所（NIHR）健康技术评估计划资助，将在 ；第 23 卷，第 45 期。请访问 NIHR 期刊库网站以获取更多项目信息。
