The Whys and Wherefores of Reducing Cannabis Use in Early Psychosis: A Qualitative Study of Service Users' Experiences of Quitting and the Support.

Objectives: Cannabis is the most widely used substance among people with recent onset psychosis, but it can have significant negative consequences for long term wellbeing in this cohort. We explored the perspectives of people with recent onset psychosis who used cannabis on their motivations for quitting, their experiences of trying to do so, and their views of the support they had received and the strategies that they had tried. Methods: Twenty one-to-one qualitative interviews were conducted with Early Intervention in Psychosis service users in England who had participated in the CIRCLE trial. Purposive sampling was used to recruit a mix of demographic, cannabis use status, and other characteristics. Results: Quitting cannabis is often very challenging for people and can require making substantial changes in their lives, including to their social relationships, living arrangements, or pathways through work or education. Participants reported wanting help, but often experienced support from mental health services as insubstantial and poorly tailored. Support from peers with relevant lived-experience, where available, was highly valued. Common reasons for quitting included its impact on key life goals or engaging with hobbies, finances, mental health, incompatibility with self-image, and negative use expectancies of intoxication. Concerns regarding mental health were primarily related to psychotic illness, including fear of exacerbating symptoms or experiencing future hospital admissions. Discussion: It is currently unclear how best to support people in this cohort. Interventions that provide support from people with relevant lived experience may be more valued and more clinically effective than current offerings.