Thank you very much, Madame Chair. I just have to ask Dr. Walsh if he wouldn't mind stepping over here and working the French side of my presentation, because I only have so many hands. If we could set the time when I begin that would be great.
Thank you, Madame Chair.
My name is Philippe Lucas. l'm a Ph.D. student in the University of Victoria's social dimensions of health program, a graduate researcher with the Centre for Addictions Research of British Columbia, and vice-president of Patient Research and Services at Tilray, is a federally licensed medical cannabis company located in Nanaimo, B.C.
Today my presentation will explore the impacts of cannabis use on both individuals and society as a whole, with a focus on addiction. So let's begin by answering a crucial question, is cannabis addictive?
Evidence suggests that only about one in ten regular cannabis users develops problematic patterns of use and, as you can see from this chart, studies have found cannabis to be considerably safer and less addictive than many licit and illicit substances, including nicotine, alcohol, and even caffeine. For those who do develop a dependence on cannabis, withdrawal is typically mild and short-lived. According to the DSM-V, the symptoms of cannabis withdrawal include irritability, loss of appetite, and sleeplessness lasting a few days to a few weeks, and the majority of Canadians who give it up do so without the need for formal addiction treatment.
Despite its low potential for abuse, for decades cannabis was touted as a potential gateway or stepping stone to harder drugs; however, both social and clinical research have convincingly debunked the gateway theory.
The Senate Special Committee on Illegal Drugs 2002 report on cannabis concluded that while it may be true that many people who use hard drugs have also used cannabis, the reasons range from social factors such as poverty to the illegal status of cannabis, which ultimately results in the black market control of its distribution. As the Senate discovered, Canadian drug use trends simply do not support the gateway or stepping stone hypothesis, concluding that, and I quote, “...while more than 30% [of Canadians] have used cannabis, less than 4% have used cocaine and less than 1% heroin”.
Additionally, recent evidence suggests that rather than being a gateway to addiction, for some people cannabis has proven to be an exit drug for problematic substance use. A number of studies on both humans and animals have found that the cannabinoid system plays a role in dependence and addiction to both licit and illicit substances. For example, research shows that nicotine cravings can be modulated by the endocannabinoid system, and recent studies suggest that cannabinoid receptors interrupt signaling in the opioid receptor systems, affecting both cravings for opiates and withdrawal severity. Labigalini Jr. et al studied this effect on people with a dependence on crack cocaine, reporting that 68% of the 25 subjects who self-medicated with cannabis in order to reduce cravings were able to give up crack altogether.
Furthermore, research suggests that cannabis use does not interfere with substance abuse treatment. Data from the California outcomes measurement system found that medical cannabis patients fared equal to or better than non-cannabis users in important outcome categories such as treatment completion, criminal justice involvement, and medical concerns. More recently, Scavone et al examined the impact of cannabis use during stabilization on methadone maintenance treatment in 91 patients with a dependence on opiates, finding that opiate withdrawal decreased in patients using cannabis, thereby improving overall methadone treatment adherence and outcomes.
My own research supports these findings. I recently conducted a cross-sectional survey of the subjective impact of medical cannabis on the use of both licit and illicit substances as self-reported by 404 medical cannabis patients, finding that 75% of respondents report substituting cannabis for another substance: 67% use cannabis as a substitute for prescription drugs, 41% as a substitute for alcohol, and 36% as a substitute for illicit substances like crack cocaine and crystal meth.
These findings are further reflected in results from the “Cannabis Access for Medical Purposes Survey”, otherwise known as CAMPS, which is the largest polling of Canadian medical cannabis patients to date. Overall, 86% of CAMPS participants reported using cannabis for at least one other substance: 80% of patients stated they used cannabis as a substitute for prescriptions drugs, 51% as a substitute for alcohol, and 32% used it as a substitute for illicit substances.
Patients who listed a greater number of symptoms were more likely to report cannabis substitution, and interestingly, patients below 30 years old were far more likely to substitute cannabis for prescription drugs, alcohol, and illicit substances than those 50 and over.
In regard to youth, a survey of 67 UBC students aged 17 to 24 that examined cannabis and alcohol use over the last six months found that 71% reported drinking more slowly when using cannabis, 53% reported drinking less when using cannabis, and 34% stated they didn't desire alcohol when using cannabis, with 0% reporting increases in alcohol cravings. This suggests that for some students cannabis is a conscious means of reducing alcohol use.
That's the state of knowledge about cannabis and addiction, but what about the impact of cannabis use on society as a whole? The current government has made crime reduction a central part of its platform, so it may be useful to understand if an increase in the use or social acceptance of cannabis leads to an increase in crime. Interestingly, a new study by Morris et al on crime rates in U.S. states that legalized medical cannabis found that there was actually a net reduction in rates of homicide and assault in medical cannabis states compared to neighbouring jurisdictions.
The authors suggest:
Given the relationship between alcohol and violent crime, it may turn out that substituting marijuana for alcohol leads to minor reductions in violent crimes that can be detected at the state level.
So what are the public health impacts of Canadians using cannabis instead of alcohol, pharmaceuticals, and illicit substances? In light of the alarming rise in addiction to prescription opiates in Canada, a growing body of research suggests that cannabis may prove to be a safe and effective substitute for patients treating chronic pain as well as non-medical opiate users.
Additionally, since the intravenous use of opiates, crack and cocaine, and crystal meth can all lead to the transmission of serious chronic conditions like HIV/AIDs and hepatitis C, evidence suggesting that cannabis might be an effective substitute for these substances can be part of a public health-centred strategy aimed at reducing disease transmission and overdoses from injection drug use. Since alcohol has a far greater social, health, and financial impact on individuals and communities than all illicit substances combined, public policies informed by the growing evidence that cannabis might reduce or even treat alcohol dependence could have a significant impact on overall rates of alcoholism, and consequently on alcohol-related automobile accidents, domestic violence, and violent crime.
To sum up, cannabis is not particularly addictive and 90% of regular users never develop a dependence on it. Furthermore, a growing body of evidence suggests that cannabis, once thought of as a gateway drug to addiction, may ultimately prove to be an exit drug to problematic substance use for some individuals. In light of this research, policies that reduce the penalties associated with cannabis use or regulate legal access by adults could reduce the harms associated with alcohol and problematic substance use on both public health and safety and could even lead to a reduction in violent crime in Canada.
I'd like to end by thanking the House of Commons for inviting me here today, and Tilray, the Centre for Addictions Research of BC, and the University of Victoria for supporting my research.
I look forward to your questions. Thank you, Madam Chair.