OBJECTIVE: Cannabis use is associated with a younger age at onset of psychosis, an indicator of poor prognosis, but better cognitive function, a positive prognostic indicator. We aimed to clarify the role of age at onset and cognition on outcomes in cannabis users with first-episode schizophrenia as well as the effect of cannabis dose and cessation of use. METHODS: Ninety-nine patients without...
BACKGROUND: It is unclear if research findings support clinical opinion that cannabis use leads to worse outcomes in people with psychosis, or whether this impression is confounded by other factors. AIMS: To systematically review the evidence pertaining to whether cannabis affects outcome of psychotic disorders. METHOD: We searched 10 relevant databases (to November 2006), reference lists of...