CCP RCT
Research type
Research Study
Full title
TESTING THE EFFICACY OF THE CANNABIS CLINIC FOR PSYCHOSIS (CCP) INTERVENTION FOR CANNABIS USE REDUCTION/CESSATION IN FIRST EPISODE PSYCHOSIS PATIENTS WITH CANNABIS USE DISORDERS (CUD)
IRAS ID
361577
Contact name
Marta Di Forti
Contact email
Sponsor organisation
King’s College London
Duration of Study in the UK
2 years, 11 months, 30 days
Research summary
People suffering from psychosis who use cannabis experience more relapses, long and compulsory admissions, with huge costs to the individual, families and health services. The Cannabis Clinic for Psychosis (CCP) was developed to respond to this clinical need. A published review of the CCP's intervention showed its safety and efficacy in supporting people suffering from psychosis with reducing their cannabis use. Nevertheless, for the CCP model of care to be applied widely and benefit a larger clinical population, its intervention needs to be tested in a Randomised Control Trial (RCT). The proposed CCP RCT is a waiting list randomised controlled trial that aims to evaluate the clinical efficacy of the existing CCP intervention. Participants will be adults currently under the care of South London and Maudsley (SLaM) Early Intervention Teams for first onset psychosis, who are dependent on cannabis and who express an intention to reduce or stop their use. The RCT primary outcome will measure changes in all participants' cannabis use. Participants will be randomised to either the intervention group or the waiting list control group receiving Treatment As Usual (TAU). The CCP intervention comprises 12 weekly (+/- 4 weeks) one-to-one sessions, with optional participation in a weekly online peer group. Sessions are delivered by trained clinicians and include evidence-based psychosocial techniques, including Motivational Interviewing (MI), Cognitive Behavioural Therapy (CBT), and support for co-occurring tobacco use. The treatment is non-pharmacological and administered via participant-led approach that accommodates online or face-to-face sessions to meet the patient preference. Qualitative data from the recent CCP proof of concept paper indicate that the flexibility in allowing patients choice on the session’s modality (online/face to face, hybrid) increased and maintained engagement.
The study is fully funded by the Maudsley Charity and due to last 30 months from the start of recruitment.REC name
London - Camberwell St Giles Research Ethics Committee
REC reference
25/LO/0877
Date of REC Opinion
13 Jan 2026
REC opinion
Further Information Favourable Opinion