Effects of motivational groups for people with psychosis who use cannabis

Objective. - Cannabis abuse is a common problem in people with schizophrenia. This pilot study aims to test the feasibility and measure the effectiveness of the motivational groups developed by Van Horn and Bux. Methods. - Fifteen patients suffering from schizophrenia spectrum disorder in a study on the effectiveness of brief motivational intervention have participated in a three motivational group sessions. The number of joints smoked per week has been measured at study entry, 3, 6 and 12 months. The motivational intervention took place during the first 6 months of the study, participants were then followed until 12 months after study entry. Results. - Participants received an average of 5.7 (2.7) individual sessions of motivational interviewing and 2.6 (1.2) group sessions. Participants significantly reduced their use of cannabis at 3, 6 and 12 months and effect sizes were strong at 3 and 6 months and moderate at 12 months. Discussion. - Motivational group intervention is feasible in a French-speaking environment with patients suffering from schizophrenia who smoke large quantities of cannabis. The results of the study are limited by the fact that this particular aspect of the intervention has not been controlled. (C) 2012 Elsevier Masson SAS. All rights reserved.