Cannabis May Pose A “Modest” Risk For Those Vulnerable To Schizophrenia, Report Says

Oxford, United Kingdom: Cannabis use may be a “modest statistical risk factor” in populations vulnerable to schizophrenia or other mental health diseases, according to a review published by the Beckley Foundation Drug Policy Programme in Britain. The Beckley Foundation is an independent think tank that analyzes drug use and drug policy.

The review, “Cannabis and Mental Health: Responses to the Emerging Evidence,” finds that cannabis, like alcohol, may “precipitate schizophrenia in people who are already vulnerable for individual or family reasons.” Authors add, however, that the “increased rates of cannabis use in the last thirty years have not been accompanied by a corresponding increase in the rate of psychosis in the population.”

The report concludes, “The studies reviewed here suggest that cannabis is a modest statistical risk factor and the vast majority of young cannabis smokers do not develop psychosis, supporting the hypothesis that a small minority of users may be vulnerable to the effects of cannabis.”

The Beckley Foundation’s findings are similar to those of Britain’s Advisory Council on the Misuse of Drugs (ACMD), which concluded earlier this year: “Based on the available data, the use of cannabis makes (at worst) only a small contribution to an individual’s risk for developing schizophrenia. … For individuals, the current evidence suggests, at worst, that using cannabis increases lifetime risk of developing schizophrenia by one percent.”

For more information, please contact Paul Armentano, NORML Senior Policy Analyst, at (202) 483-5500. Full text of the Beckley Foundation report is available online at: http://www.internationaldrugpolicy.net/. Additional information on cannabis and mental health is available in NORML’s report, “Cannabis, Mental Health, and Context: The Case For Regulation,” available online at: http://www.norml.org/index.cfm?Group_ID=6798