Effects of Cannabidiol on Psychiatric Symptoms, Cognition, and Cannabis Consumption in Cannabis Users With Recent-Onset Psychosis

A large proportion of people with a schizophrenia-spectrum disorder, especially in the early stages of the disease, regularly consume cannabis. Cannabis use is associated with poor prognostic outcome; however, there are no effective interventions targeted at reducing cannabis use or its deleterious effects in this population. The present trial is designed to test whether cannabidiol (CBD), a cannabinoid whose effects are in many ways antagonistic to those of Δ9-tetrahydrocannabinol (THC), can reduce psychiatric symptoms, cognitive deficits, and cannabis use in people with recent-onset psychosis who regularly consume cannabis.