Predictors of cannabis use in men with and without psychosis

Background: Factors associated with cannabis use among people with psychosis are not well understood. Aims: To examine whether people with psychosis and age-matched controls modified cannabis use in response to recent experiences. Method: This study predicted 4 weeks of cannabis use prospectively, using expectancies derived from recent occasions of use. Results: People with psychosis used cannabis less frequently than controls, but had more cannabis-related problems. More negative cannabis expectancies resulted in less frequent cannabis use over Follow-up. The psychosis group was more likely to moderate cannabis use after negative effects than controls. Conclusions: Results offer optimism about abilities of people with psychosis to moderate cannabis use in the short term. (C) 2007 Elsevier Ltd. All rights reserved.