March 19, 2005: Changing Cannabis Classification?

Home Secretary Charles Clarke has written to the Advisory Council for the Misuse of Drugs (ACMD). The AMCD has been asked by the Home Secretary to reassess its position on the classification of cannabis and provide advice on the claims of greater prevalence of increased strength cannabis. The Advisory Council on the Misuse of Drugs is a statutory and non-executive nondepartmental public body, which is established under the Misuse of Drugs Act 1971.Cannabis and cannabis resin together with cannabinol and its derivatives were reclassified as Class C drugs in January 2004.

Charles Clarke’s letter, addressed to AMCD Chair Professor Sir Michael Rawlins of the University of Newcastle’s Wolfson Unit of Clinical Pharmacology, reads as follows:

"In 2001, my predecessor David Blunkett commissioned the Advisory Council to provide a report on the classification of cannabis. The subsequent publication of March 2002 ‘The classification of cannabis under the Misuse of Drugs Act 1971’ recommended that cannabis should be reclassified to a Class C drug from Class B. The Government was content to accept that recommendation and in January 2004 the necessary legal changes were made with the full backing of the Association of Chief Police Officers."

"Since then there is no indication from either the British Crime Survey or the more recent Schools Survey by the Department of Health that use of cannabis has increased. However, there have been several studies produced since the decision to reclassify cannabis was taken."

"I am thinking in particular of the longitudinal studies into links and associations between taking cannabis and developing mental problems. The Ferguson study (New Zealand 2004) considered how regular cannabis use increased the risk of developing psychotic symptoms later in life. Professor van Os more recent paper (Maastrict University 2004) concluded "Cannabis use moderately increases the risk of psychotic symptoms in young people but has a much stronger effect in those with evidence of predisposition for psychosis.""

"I realise that ACMD keeps a close interest in these studies and continue to monitor all the relevant evidence on the effects of cannabis. I want to be clear what influence the evidence presented within these studies has on the overall assessment of the classification of cannabis. I think there is merit in the Advisory Council assessing whether their position is at all changed by the emerging evidence."

"I would also welcome advice on claims of increased prevalence of cannabis with high levels of Tetrahydrocannabinol (THC). Typically these are grown hydroponically and are known as ‘skunk’ varieties of cannabis. I am aware the Dutch Government are taking a particular interest in very high strength strains and are considering whether cannabis above a certain strength should be a higher classification."

"I am grateful for the advice that the ACMD provide on these and other drug issues and look forward to your response."