Multimodal Assessment of Cannabinoid Target Engagement in Adults With Obsessive-Compulsive Disorder

The purpose of this research study is to test how a medication called nabilone (Cesamet) affects neurocognitive processes involved in obsessive-compulsive disorder (OCD), including threat response, processing of fear signals, and habitual behavior. OCD is a disabling illness that affects around 2% of the population and involves recurrent intrusive thoughts (obsessions) and repetitive behaviors (compulsions) that lead to distress and/or impaired functioning. Nabilone is a synthetic form of delta-9-tetrahydrocannabinol (THC, the primary psychoactive component of the cannabis plant). It acts on the brain's endocannabinoid system, which has been hypothesized to play a role in OCD symptoms. Nabilone is approved by the FDA for the treatment of chemotherapy-induced nausea and vomiting. It is not FDA-approved for treating OCD. In this study, 60 adults with OCD will receive a single dose of either nabilone or placebo. Participants will then complete a series of assessments including neuroimaging, psychophysiology (e.g., skin conductance recording), computerized behavioral tasks, and self-report measures. The information gained from this study could contribute to the development of new treatments for people with OCD and related disorders.