Cannabis use has been associated with the onset, course and relapse of psychosis. Population studies and data from samples of young people at high risk for psychosis have indicated that cannabis use may be related to the onset of psychosis. Cannabis use has also been found to have a deleterious impact on psychotic symptom severity and has emerged as the strong predictor of psychotic relapse. To date, there has been little collaboration between neuroscience and clinical research groups examining the link between cannabis use and psychosis, despite the potential for these fields to inform the other. This symposium seeks to begin to redress this gap.