2743 – Why do first-episode psychosis patients use cannabis? Case-control study

Introduction There is a high prevalence of cannabis use among patients with psychosis. Persistent cannabis use in firstepisode psychosis affects prognosis and recovery. Understanding the reasons of cannabis use may help improve psychosis outcome. Several studies suggest that cannabis is used to ameliorate symptoms related to the disorder (self-medication hypothesis). Comparing the reasons of cannabis use in first-episode patients with a control group, may help to acknowledge that question. So far few studies with a control group have been carried out. Aim Identify the reasons of cannabis use in first-episode psychotic cannabis users and compare them to non-psychotic cannabis users. Methods Thirty-two first-episode psychosis cannabis users and thirty-four non-psychotic cannabis users were included. They completed a self-reported reasons for use cannabis questionnaire, adapted from Dixon et al. Results The amount and frequency of cannabis use was higher in patients with first-episode psychosis than controls (6.47+/- 8.2 patients vs 19.59+/- 27.7 controls; p=0.024). The two groups did not differ significantly in any of the reasons for cannabis use. The main factors attracting them to use cannabis were: relaxation, sleep better, getting high and pleasurable experiences. Conclusion Both first-episode psychosis and controls seem to use cannabis for the same reasons, which does not support the self-medication hypothesis. However additional research would be necessary to further investigate cannabis use correlation with symptoms to discard that hypothesis. Recognition of the actual reasons of use should help prevention strategists to develop appropriate programmes to general and specific audiences.