Cannabis: Mental Illness

Health written question – answered on 31st October 2011.

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Photo of Charles Walker Charles Walker Conservative, Broxbourne

To ask the Secretary of State for Health what research projects his Department is sponsoring into any relationship between high THC cannabis and psychosis; and if he will make a statement.

Photo of Anne Milton Anne Milton The Parliamentary Under-Secretary of State for Health

With funding from the Department, the Centre for Public Health and School of Pharmacy and Biomolecular Sciences at Liverpool John Moores university produced a report summarising recent research evidence on the health harms of drugs, A Summary of the Health Harms of Drugs, which was published in August 2011.

The Advisory Council on the Misuse of Drugs published a report, “Cannabis: Classification and Public Health”, in May 2008. This found a probable but weak causal link between psychotic illness and cannabis use, but whether this would become stronger with the wider use of higher potency cannabis was uncertain.

The Medical Research Council (MRC) is one of the main agencies through which the Government support medical and clinical research. The MRC is an independent body which receives its grant in aid from the Department for Business, Innovation and Skills. Work which the MRC is currently supporting in this area includes:

Professor G. Lewis, university of Bristol: The aetiology of psychosis high-risk mental states during adolescence in the ALSPAC cohort;

Professor V. Curran, University college London: What determines an individual's vulnerability to the harmful effects of cannabis?; and

Dr P. Morrison, Institute of Psychiatry: Cannabinoids in psychosis: Mechanisms and Therapeutics.

Work is being carried out at the university of Bristol on the psychoactive properties of cannabis as part of the Severnside Alliance for Translational Research (SARTRE) collaboration.

Further details of these projects can be found on the MRC's online research portfolio at:

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Peter Reynolds
Posted on 1 Nov 2011 3:23 pm (Report this annotation)

A measured and reasonable response from Ms Milton who refuses to be pushed along the path that Charles "cocaine for kids" Walker wants to go towards reefer madness.

There is no causative link between cannabis and psychosis only an increase in risk (hardly surprising for a psychoactive substance). However, the risk as measured by Hickman et al 2009 is at worst 0.013% and probably less than 0.003%. Therefore the risk is far, far less than from the consumption of alcohol, tobacco, energy drinks, many OTC and POM medicines.

Mr Walker's intent may be honourable but he has the sham charity Cannabis Skunk Sense pushing him and using its usual mix of distorted and out of date scientific research combined with hysterical moralising.

Mr Walker needs to face up to the reality that the only real way to protect children is a regulated system that takes this £6 billion market out of the hands of criminals. Instead of this present hopeless policy of "just say no" we need to start taking responsibility.