Cognitive impairment is well established in people with psychosis and is associated with cannabis use. The current study will investigate the neurobiological basis of cognitive change associated with 28-days of cannabis abstinence in people with psychosis and non-psychiatric controls with cannabis use. Participants will be randomized to a cannabis abstinent group or a non-abstinent control group and will undergo magnetic resonance imaging at baseline and following 28-days of abstinence. This study will help characterize the neuropathophysiological processes underlying cognitive dysfunction associated with cannabis use and its recovery which may guide the development of novel interventions for problematic cannabis use.
Able to provide informed consent in English or French
Heavy cannabis use (defined as weekly cannabis use for at six months) and/or DSM-5 diagnosis of CUD
Have a Full-Scale IQ ≥ 75
Meet DSM-5 criteria for a psychotic disorder (psychosis patient arm only)
current SUD (other than CUD)
MRI contraindications
Positive urine screen for psychoactive substances other than cannabis, nicotine, or caffeine
Current suicidal or homicidal ideation
Douglas Mental Health University Institute
Lead sponsor