Saturday 21 May 2011

New Research Into Cannabis And Mental Health | CLEAR

Will Gibson, University Of Reading

Will Gibson is studying psychology at the University of Reading.  He is researching the neurological effects of cannabis consumption under the supervision of Dr Ben Whalley, Dr Claire Williams and Dr Gary Stephens.

Cannabinoids And Mental Health – A Fresh Perspective

Whilst the national media repeatedly warn about the dangers of cannabis consumption, particularly to those with pre-existing mental illness, a large number of patients with mental health issues continue to smoke the substance for recreation as well as a form of self-medication. Despite many negative presentations of cannabis in the British media, the worldwide scientific community and pharmaceutical industry are beginning to take a serious interest in the development of medicines based on the psychoactive chemicals, known as cannabinoids, contained in the plant.

The importance of good mental health is steadily increasing as a public priority; this is being reflected in an increase in prescriptions for modern anti-depressants, in particular selective serotonin re-uptake inhibitors (SSRIs).  Recent figures from Primary Care Trusts (PCT) show the number of prescriptions for products like SSRIs  have been increasing progressively since their release on the market.

Several suggestions have been made to explain this  increase, including reports from the BBC that it may be due to the economic recession: http://www.bbc.co.uk/news/health-12986314

An article from Moore et al (2010) in the British Medical Journal (BMJ) reports an increase in the numbers of prescriptions for SSRIs. It highlights the fact that many of the patients receiving a prescription for SSRI’s were doing so as part of the treatment programme for pre-existing mental health conditions and argues therefore that these figures are more of reflection in a shift of prescribing behaviour as opposed to an increase in the prevalence of mental illness.

It is increasingly common for prescribers to provide patients with SSRIs and other anti-depressant medications such bupropion hydrochloride for conditions other than their traditional indications. Such indications include; stopping smoking, anorexia, anxiety disorders, personality disorders as well as post-traumatic stress disorder (PTSD) and hormonal problems.

Regardless of whether there has been an increase in the actual prevalence of affective disorders such as depression it is clear that mental illness has a significant impact on society. The mental health charity “Mind” reports that at any one time 1 in 4 people in the UK will be suffering from a mental health condition. One in six people currently employed in the UK are suffering from depression and the impact on the economy is estimated at£26 billion per annum (Mind.org 2011).

Prescriptions for antidepressants, anxiolytics (anti-anxiety medications) and hypnotics (used for sleep disorders) are extremely costly to the tax payer. (Ref PCTs and NHS/NDFS) Furthermore, despite overwhelming support for the effectiveness of SSRIs from British prescribers the effectiveness of these drugs is a matter of continuous debate. Fournier et al (2010) conducted a meta-analysis of data collected from previous studies into these medicines and found that with mild depression scores many SSRIs are only moderately more effective than placebos.

So could cannabis and/or individual cannabinoids offer a more effective alternative?

Neuroscientists at the University of Reading have been studying the potential medical uses of cannabinoids for nearly a decade.  So far this research has mainly focused on the therapeutic benefits of cannabinoids for patients suffering from epilepsy and eating disorders.  However, plans have now been approved to research the psychological effects of various isolated cannabinoids.  GW Pharmaceuticals, which will be supplying the research materials, already has established specialist research centres dedicated to breeding cannabis plants to contain artificially high levels of certain cannabinoids and our lab will be examining the psychological effects of specific cannabinoids. Whilst there is a wealth of research into the psychological effects of the cannabis plant as a whole, we feel there is not enough information on the effect of individual cannabinoids.

Dr Ben Whalley, Dr Claire Williams, Dr Gary Stephens

The cannabinoids that this research will focus on include but are not limited to: delta-9-tetrahydrocannabinol, cannabidiol, cannabinol, cannabigerol, tetrahydrocannabivarin and cannabichromene.  Previous research into these and other cannabinoids suggest that isolated cannabinoids may have a diverse range of medical indications.  Such potential usages include prescribing certain compounds as anxiolytics, anti-depressants and sedatives. We hope to begin lab testing in June 2011 and publish results summer 2012.

Meanwhile we  are keen to hear of your experience of using cannabis therapeutically for mental health concerns or diagnosed conditions. If you are interested in contributing to this research please add a comment below.

Disclaimer: This research is essentially preliminary, all compounds are being tested on laboratory rats.  Any findings would have to be replicated in humans before they could be utilised in a medical or political decision. Please do not attempt to replicate any of our trials without Home Office approval, possession of isolated cannabinoids is regulated by the Misuse of Drugs Act 1971.

References

Increase in proportion of patients on long-term medication accounts for increase in antidepressant prescribing in UK. Evidence Based MentalHealth, 13(2):61, May 2010.

Jay C. Fournier, Robert J. DeRubeis, Steven D. Hollon, Sona Dimidjian, Jay D. Amsterdam, Richard C. Shelton, and Jan Fawcett. Antidepressant drug effects and depression severity. JAMA: The Journal of the American Medical Association, 303(1):47–53, January 2010.

Michael Moore, Ho M. Yuen, Nick Dunn, Mark A. Mullee, Joe Maskell and Tony Kendrick. Explaining the rise in antidepressant prescribing: a descriptive study using the general practice research database. BMJ, 339, January 2009.

Primary Care Trust Prescribing Data: October – December 2010 (released May 2011)

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