Reefer madness | |
Marijuana and madness. David Castle and Robin Murray (editors). Cambridge: Cambridge University Press, 2004 (xvi + 218 pp). ISBN 0 521 81940 7 |
The relationship between
marijuana use and mental illness is a hotly debated topic. Tabloid headlines refer to “supergrass” causing schizophrenia, while alternative lifestyle enthusiasts claim medicinal properties for marijuana. Social conservatives argue it is a pernicious drug that leads to harder drug use, while social progressives use its ubiquity to argue that much of the harm associated with its use comes from its criminalised status. A book that cuts through the polemic and takes a scientific view is most welcome. Castle and Murray are widely published psychiatrists (from Australia and the United Kingdom, respectively). They have assembled 13 chapters, prepared by international experts, examining the links between cannabis use and mental illness, especially psychosis. The book opens with an exploration of exogenous cannabinoids and the endogenous cannabinoid system in the brain. It goes on to explore the links between cannabis use and psychosis, with particular emphasis on schizophrenia. There are also chapters discussing depression and anxiety disorders allegedly associated with marijuana use, and whether there is a specific cannabis psychosis. Two groups explore research linking the endogenous cannabinoid system and schizophrenia. The book closes with contributions of immediate clinical relevance. These examine the motives that sustain cannabis misuse in individuals with psychosis, some strategies for addressing cannabis abuse in this population, and the residual cognitive effects of long-term cannabis use. Despite the dedication “to Francis Ames, whose belief in the potential medical and environmental benefits of marijuana was never obscured by the smoke of political rhetoric”, a balanced approach is taken to the subject. The text is densely written and heavily referenced. A great deal of attention is paid to the careful methodologies and their limitations. The conclusions drawn by each group are understandably cautious. I found this an interesting compilation of research covering a poorly understood area of great clinical relevance. Doctors who work in this field could update themselves on a large body of research by reading this book. With cannabis use continuing to rise and the causes of schizophrenia continuing to elude us, I am sure this will be an expanding field. Joshua D Geffen
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