The idea that there is a link between cannabis and schizophrenia is a controversial one. Last year the U.K. Government reclassified cannabis as a class B drug, partly, at least, because they thought there was a link between the drug and mental illness. A study of the issue by researchers from the universities of Bristol and Cambridge and from the London School of Hygiene and Tropical Medicine has been looking into the risk and has estimated that to prevent one case of schizophrenia the Government would have to persuade 2,800 young men who are heavy users of cannabis to give up; a figure that rose to 5,000 for young women. For light users of cannabis these figures rose to 10,000 young men and 30,000 young women respectively.
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