Candian Cannabis: Caveat “Hemp-tor”

Candian Cannabis: Caveat “Hemp-tor”

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Dr. Tony George
MD, FRCPC
Clinician-Scientist, Campbell Family Mental Health Research Institute, CAMH
Chief, Addictions Division, CAMH
Professor, Department of Psychiatry, University of Toronto

By: Mikaeel Valli
Photo By: Mikaeel Valli

October 17th, 2018 marked a new beginning for Canada—the legalization of cannabis for recreational use. From Southern Ontario to the Far North, from St. John’s to Vancouver, Canadians had mixed responses to this historical legislation. Many celebrated this monumental decision, while others stood in lines protesting and pushing for more regulations.

Many argue that the legalization of cannabis is a great thing for Canada for several reasons. It will shift the burden of minor crimes of trafficking and possession away from law enforcement and the judicial system towards more serious crime. This would reduce tax dollars spent on incarceration. A shrinking “black” market share for illegal cannabis products will lead to billions of dollars in tax revenues for the government. A regulated market would ensure cannabis is safely produced and contains safe levels of THC—the component which is responsible for the “high” feeling that marijuana is commonly associated with. On the social level, easier access for cannabis would reduce the stigma associated with marijuana possession and use.

However, one critical question is the mental health implications associated with drug use. The IMS Magazine had the pleasure of interviewing Dr. Tony George, a psychiatrist with a subspecialty in addictions, and a clinician-scientist at the Centre for Addiction and Mental Health (CAMH) in Toronto. Despite the advantages, Dr. George remains skeptical about this legal move. “Canada has the highest rate of cannabis use in the Western world. Among youths aged between 15 and 19, our rate is 28.5% while in the US in Washington, it is at 22%” Dr. George said with dismay. He is worried that the legalization will lead to greater increase in cannabis use in vulnerable subgroups—particularly for youth and those that are mentally ill.

He expressed further that he does not truly know what to expect, “It is going to be interesting. We are heading into the largest cannabis-use prospective study in the world. Put your seatbelt on and hold on for the ride.”

Cannabis is the most commonly used illicit drug in people with severe mental disorders. Dr. George recalled back to 1994 during his second year in residency training in Psychiatry at Yale University School of Medicine, where his interest in the intersection of addiction and mental illnesses was sparked, “I had a chance to be on a unit that deals with schizophrenia and bipolar disorders… what I realized was that just about every one of those patients had an addiction problem.” He elaborated that most times, these patients are brought to the hospital as a result of their relapse to cocaine, alcohol, or other illicit drug use. Dr. George added that clinically, cases of addiction often get overlooked or are viewed as a non-primary issue—which is a challenge that needs to be addressed.

In those with schizophrenia, about 25% have cannabis use disorder. Similarly, a high percentage (10-15%) of individuals with major depression and bipolar disorder also have a maladaptive use of cannabis. Compare this to the general population where it is only 3%. The use of cannabis “is like an accelerant to fire” for these vulnerable populations as it significantly worsens their mental illness, Dr. George warned. Cannabis use leads to longer psychotic and mood episodes, resulting in more relapses and re-hospitalizations, thereby increasing treatment needs. Dr. George’s advice to the vulnerable Canadians that are interested in buying cannabis is: “caveat hemp-tor—let the buyer beware of the risks of cannabis.”

Given the high prevalence of addiction in mental disorders and how misuse of drugs significantly impacts their day-to-day function, Dr. George leads the Biobehavioural Addictions and Concurrent Disorders Research Laboratory (BACDRL) at CAMH to devise novel treatment methods to combat addiction in patients with schizophrenia, bipolar disorder, and depression. One of the main projects funded by the US National Institutes of Health is a double-blind, randomized control study examining the effects of repetitive transcranial magnetic stimulation (rTMS) on cannabis use and cognitive outcomes in schizophrenia (abbreviated as “CANSTIM”). This trial is led by Karolina Kozak, an IMS PhD student. In the treatment arm, patients with cannabis use disorder receive brain stimulation at the dorsolateral prefrontal cortex—a region responsible for cognition including working memory and executive functioning. In the control arm, patients with cannabis use disorder receive a sham rTMS, which mimics the look, sound, and feel of rTMS without receiving actual stimulation to the brain. Kozak explained that this trial is under way, “and we hope that this approach with rTMS will be effective in the management and treatment of cannabis use disorder in schizophrenia patients and improve their cognitive and functional impairment.”

Another study that is an extension of the CANSTIM project is aimed at predicting cannabis abstinence using cognitive and clinical factors. Dr. George and his IMS Master’s student, Darby Lowe, are using baseline clinical, neuropsychological, and neurophysiological data from the CANSTIM project and examining its association with cannabis use reductions and abstinence during the CANSTIM trial. Lowe expressed that that they hope to “determine the clinical and cognitive markers for the ability and inability to abstain from cannabis. This will help highlight potential therapeutic targets, therefore aiding with addiction and abstinence in schizophrenia.”

In addition to examining the schizophrenia population, the BACDRL also looks at patients with mood disorders. In particular, Aliya Lucatch—an IMS Master’s student—is exploring the effects of extended cannabis abstinence on symptoms and cognition in patients with major depressive disorder. This is a longitudinal study with eight study visits involving a variety of clinical assessments relating to depression, anxiety, and mood, as well as cognitive assessments to evaluate memory and attention. These patients are also provided behavioral coaching to provide motivational support to help with their cannabis addiction. As an incentive, a $300 cash bonus is provided at the end of the 28 days if successful cannabis abstinence is achieved. Lucatch added that this study “will provide new insights about the impact of heavy cannabis use on major depression. Given that cannabis was recently legalized, it is important to have a good understanding of the potential risks which might impact policies and public perception.”

When asked about the challenges associated with his lab research, Dr. George quickly replied, “funding!” Dr. George expressed that the funding agencies need better awareness of the importance of mental health and its impact on daily functioning as there is still stigma of mental health that is persistent in our society. “The best way to combat this stigma is through dissemination of knowledge” Dr. George expounded. However, on the flipside to the legalization of cannabis is the increase in tax revenues from cannabis sales, and Dr. George hopes that the revenue will be used towards funding mental health research and combatting addictions in these vulnerable populations.

Through his research and clinical practice, Dr. George hopes to leave the legacy of “approaching complex problems in mental disorders in a rational way. If we ask the right questions, and we follow through with it, we would learn more about it—and thereby be able to help a lot more patients improve their lives.”