Abstract
Few studies have evaluated, in patients with symptomatology the impact of cannabis use on the duration of hospitalization and on short- and medium-term developments. The objective of this study will be to assess the impact of cannabis on the duration, the hospitalization and the short- and medium-term evolution of patients with psychotic symptoms and cannabis use. We hypothesize that these patients (in comparison with patients with psychotic symptomatology and not using cannabis) would be hospitalized more long, exposed to a higher risk of resistance to the usual therapeutics, would have a lack of therapeutic alliance and insight, relapses and hospitalizations more frequent, more marked negative symptoms and lower quality remission. They would also be more prone to impulsive and aggressive behaviour.