Objective: The aim of the paper is to review the effects of Cannabis sativa on the human brain.
Method: A selective literature review was undertaken.
Results/conclusions: Cannabis sativa causes an acute and, with regular heavy ingestion, a subacute encephalopathy. There is no evidence of irreversible cerebral damage resulting from its use, although impairment of information processing might be a long-term consequence of heavy prolonged use. The precise relationship of cannabis to the functional psychoses such as schizophrenia has yet to be clarified.