Cannabis intoxication can precipitate severe psychiatric reactions including paranoia, mania and schizophrenic-like states.” She also said “Cannabis can aggravate or precipitate schizophrenia in vulnerable individuals and may antagonise the therapeutic effects of anti-psychotic drugs in previously well-controlled schizophrenic patients”.
Professor C. H. Ashton, Department of Psychiatry, University of Newcastle upon Tyne
in evidence submitted to the House of Lords Select Committee April 1998
in evidence submitted to the House of Lords Select Committee April 1998