Book Review: Marijuana: The Unbiased Truth about the World’s Most Popular Weed

This timely book by psychiatrist Dr. Kevin Hill increases awareness and understanding of the problems associated with the legalisation and medicalization of marijuana, an issue of great interest to Canadians. While the book is written for the lay audience, it contains information relevant to the practice of all physicians, especially psychiatrists. Students would also benefit from reading this book. Nine percent of adults and 17% of adolescents will become addicted to marijuana with destruction of social, occupational, and educational goals. These are large numbers considering that more than 47% of Americans age 12 or older use marijuana during their lifetime. Hill describes the short-term effects of marijuana, including the slowed reaction time affecting driving. The longterm effects include impaired executive brain function, structural brain changes, and a lowering of IQ with early, regular marijuana use. Although marijuana may temporarily reduce anxiety, Hill describes how anxiety levels rebound to even higher levels when the marijuana wears off, thus creating a cycle of increasing marijuana use. The delta-9-tetrahydrocannabinol (THC) component of marijuana (the ingredient producing the ‘high’ users want) has increased from 1%-2% to 13% (even as high as 27%), and these increased levels often trigger anxiety attacks. Hill highlights the very unpleasant features of marijuana withdrawal, explaining how irritability, anger, anxiety, and insomnia make quitting so difficult. According to Hill, legalisation of marijuana in the United States could save $7.7 billion per year by ceasing the enforcement of prohibition with an additional $6.2 billion per year raised through tax revenues. The black market would continue by selling to children and teenagers, avoiding taxation and providing marijuana with higher THC content. With a joint containing a half gram of marijuana and 1 ounce equivalent to 28 grams or 56 joints, Hill describes how excessive amounts are prescribed (and later sold to others). In our mental health clinic at the Markham Stouffville Hospital, adolescents report how they obtain marijuana from ‘friends’ who have obtained medical marijuana through their doctor. Hill describes 2 active ingredients (or cannabinoids) contained in marijuana: THC (‘psychoactive’) and cannabidiol (CBD; ‘calming’), explaining how increasing THC levels typically lower CBD levels. Two cannabinoids are available in the United States that are approved by the Food and Drug Administration for nausea and vomiting associated with cancer chemotherapy and appetite stimulation in wasting illnesses (e.g., human immunodeficiency virus): dronabinol (Marinol) and nabilone (Cesamet). By prescribing cannabinoids as tablets, it is possible to control dose, enable time release, avoid harmful toxins, and avoid respiratory diseases. Dronabinol is not available in Canada. Hill details the weak evidence supporting the use of cannabinoids for chronic pain and neuropathic pain, noting that 50% of the trials are negative. ‘Data does not support the use of medical marijuana for most of the disease entities for which people intend to use it as treatment’ (p. 111). Hill advises us to ‘stop glamorizing the use of marijuana and instead portray it as the potentially harmful and addictive drug that it is’ (p. 181). The book concludes with a section on the treatment of marijuana addiction, including advice for relatives and loved ones of those suffering from the deleterious effects of this toxic substance. We believe that this book will be of benefit to all health care providers and better prepare them for the ongoing public debate in Canada on marijuana. The Canadian Journal of Psychiatry / La Revue Canadienne de Psychiatrie 2017, Vol. 62(5) 355 a The Author(s) 2017 Reprints and permission: sagepub.com/journalsPermissions.nav TheCJP.ca | LaRCP.ca Canadian Psychiatric Association