Journal article

Cannabis use and psychosis: a review of clinical and epidemiological evidence

W Hall, L Degenhardt

Australian & New Zealand Journal of Psychiatry | BLACKWELL SCIENCE ASIA | Published : 2000


OBJECTIVE: This paper evaluates evidence for two hypotheses about the relationship between cannabis use and psychosis: (i) that heavy cannabis use causes a 'cannabis psychosis', i.e. a psychotic disorder that would not have occurred in the absence of cannabis use and which can be recognised by its pattern of symptoms and their relationship to cannabis use; and (ii) that cannabis use may precipitate schizophrenia, or exacerbate its symptoms. METHOD: Literature relevant to drug use and schizophrenia is reviewed. RESULTS: There is limited clinical evidence for the first hypothesis. If 'cannabis psychoses' exist, they seem to be rare, because they require very high doses of tetrahydrocannabinol,..

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