'For 150 years it has been known that acute intoxication with cannabis can induce hallucinations and delusions. However, this was thought to be a transient effect which usually rapidly resolved itself. Then in the late 1980s and 1990s psychiatrists like me began to see growing numbers of young people with schizophrenia who were taking large amounts of cannabis.We first thought that they were self-medicating in an attempt to ameliorate their anxiety and paranoia. However, since their families often told us that cannabis seemed to exacerbate the symptoms, we decided to examine this. When we followed up 119 young people who had been diagnosed with schizophrenia, we discovered that far from being helped by cannabis, those who continued to take the drug four years later were three times more likely still to be hallucinating and deluded than non-consumers.'
Professor of Psychiatry, Robin Murray, Maudsley Hospital.
