Studying Brain Changes and Cognitive Function After 28 Days of Cannabis Abstinence in People With Psychosis and Cannabis Use Compared to Non-Psychiatric Cannabis Users

What this Trial Is About

Researchers are investigating how 28 days of abstaining from cannabis affects brain function and cognitive abilities in people with psychosis who use cannabis, as well as in non-psychiatric controls who use cannabis. The study aims to better understand the brain changes linked to cannabis use and cognitive problems, and how these might recover after stopping cannabis. This research could help develop new treatments for problematic cannabis use. The study is interventional and involves brain imaging and cognitive testing in both patient and control groups. Participants will be assigned randomly to either a group encouraged to abstain from cannabis for 28 days using contingency management, or a control group that continues their usual cannabis use. The study includes psychosis patients who use cannabis, non-psychiatric cannabis users, and non-psychiatric controls who do not use cannabis. All participants will undergo magnetic resonance imaging MRI and complete a memory task both at the start and after 28 days. Urine samples will be collected twice weekly to confirm abstinence. During the study, participants will complete brain scans and cognitive tests at baseline and after 28 days to measure changes in brain activity and structure, including gray matter volume, cortical thickness, and diffusion. Researchers will also monitor behavior during memory tasks and verify cannabis abstinence biochemically. The total involvement spans the 28-day intervention period with follow-up assessments, helping to understand neural recovery and cognitive changes related to cannabis use.

Investigating the Neural Correlates of Cognitive Function in Psychosis Patients and Non-Psychiatric Controls With Cannabis Use