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HESA Committee Report

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Dissenting Report by the Liberal Party of Canada on the Health Committee’s
Report: “Health Risks and Harms of Marijuana”

By Hon. Dr. Hedy Fry, P.C., M.P. for Vancouver Centre
and Liberal Party of Canada Health Critic

In April 2014 the House of Commons Standing Committee on Health ‎passed a motion to undertake a study, of no more than 5 meetings, examining the scientific evidence related to the health risks and harms associated with the use of marijuana.

The Liberal Party of Canada ‎rejects the majority report from that study and presents a Dissenting Report for the following reasons:

  • The final report does not reflect the testimony and advice that we heard from the expert witnesses who presented to Committee. Much of the testimony we heard during the study, specifically around scientific evidence, is absent from the report.
  • We consider the study to be inherently flawed. Liberals had asked for the study to include benefits as well as harms and ‎risks. This is the objective, scientific manner, in which all drugs are assessed, and despite recommendations by many witnesses, it was not included as part of the study.

This is what the Committee heard:

Marijuana is a hemp plant, Cannabis Sativa and contains 489 distinct compounds. Delta 9 THC Tetrahydrocannabinol is responsible for most of the euphoric and addictive effects of cannabis, since it stimulates the endocannabinoid (eCB) receptors of the brain which produce psychotropic and neural developmental effects. Other cannabinoids are present in lesser amounts and do not have psychotropic effects. 

Health Canada officials reported that marijuana in Canada today has a much higher ‎THC than in the past. US data shows cannabis in the 1980s to have 1% THC to between 10%-11% in 2011. Marijuana grown indoors on the west coast of Canada can have 30% or more THC content.

Incidence of Use:

Health Canada cites the 2012 Canadian Alcohol and Drug Use Monitoring Survey (CADUMS) showing that 10.2% of Canadians (mostly men) have used marijuana in the past year; 41.5% report using it at least once in their lifetime with 25% being chronic users. Dr. Perry Kendall, British Columbia’s Chief Public Health Officer, cited the 2011 CADUMS survey showing 17.7% ‎who use cannabis do so for medical purposes: 50% for pain and the other half for depression, insomnia and anxiety, which suggest a medical benefit of marijuana.

‎Incidence among youth remained at 20.3%. A UNICEF survey found that Canadian youth 11 to 15 are among the highest peer users in other developed countries which shows that the current system does not prevent youth use.

Dr. Philippe Lucas of the University of Victoria noted that, in other jurisdictions, regulated access to marijuana was associated with a decrease in recreational use of other drugs, such as alcohol and prescription drugs. Dr. Evan Wood of the BC Centre of Excellence for HIV/AIDS and Urban Health Research pointed out that the illegal status of marijuana does not prevent youth access, since 80% of young people in a US survey suggest cannabis is easy to attain. Dr. Le Foll of the University of Toronto and Dr. Didier Justras-Aswas of the Universite de Montreal recommended legalizing marijuana through a system of strict regulation of use and taxation would help reduce its health risks and harms by allowing for control and oversight of content, including the levels of THC. This, in turn, would reduce the drugs addiction potential. The taxation could be used to promote less harmful ways of using marijuana, such as vapour systems. These testimonies were not included in the majority report. However, they were compelling enough for us to recommend:

Recommendation 1: The Government of Canada explore a regulatory framework of legalization, working with experts in the field that aims to keep marijuana out of the hands of youth.

Perceptions of marijuana use by the public:

Most youth and parents perceive marijuana to be harmless, compared with other drugs. Yet, the Canadian Centre on Substance Abuse studies report cannabis to be the second most widely used illicit drug among persons accessing publicly funded addiction services‎. Data from 2002 showed that hospitalisations in Canada related to cannabis accounted for 0.3%, alcohol for 5.8% and tobacco for 10.3%. In terms of cannabis, direct costs to the health care system in 2002, was $73 million; alcohol $3.3 billion and tobacco, $4.4 billion. Most witnesses stressed the importance of raising awareness of potential health risks and harms as a key means of reducing the rate of use and cannabis-impaired driving. Dr. Tony George of the University of Toronto said studies in the United States found if the perception of harm among youth increases, the rate of cannabis use decreases, but warned that youth public awareness campaigns need to focus on accurate information, rather than using “scare” tactics, which have been shown to be less effective. This leads us to make the following recommendation:

Recommendation 2: The Government of Canada work with relevant stakeholders and experts to develop a campaign to raise public awareness and knowledge of the risks and harms associated with marijuana use.

‎Some witnesses stated that health risks attributed to marijuana use ranged from cognitive impairment, brain development, respiratory effects, mental health problems, motor vehicle accidents and cardiovascular disease. Specifically, it impairs decision-making ability, reaction time and memory, yet this effect was higher in infrequent users than chronic users. Yet, many other witnesses noted that there was no direct causality between chronic marijuana use and long-term cognitive deficits. Indeed there was a comprehensive meta-analysis at the University of British Columbia that showed no substantial systemic effect of long-term cannabis use and neurocognitive function.

Some witnesses suggested there were long-term effects of marijuana toxicity on the lungs, associated with lung cancer, yet others suggested that research in this area is unclear and more studies are necessary.

Some witnesses linked marijuana with impairment of cognitive and psycho-motor skills that could lead to driver impairment; yet others suggest that many of the traffic fatalities related to cannabis use included multi-drug use or cannabis use in combination with alcohol.

Some researchers pointed out that in youth, however, MRIs and ‎brain activity studies showed that the developing pre-frontal cortex in youth could make them more sensitive to the neuro-toxic effects of marijuana. Other researchers warned that other factors could contribute to intellectual attainment such as socio-economic status, social stress and personality characteristics.

In summary, there was contradictory evidence about the benefits and harms of cannabis. Some researchers say that cannabis increases anxiety and psychosis. Other point to the anti-psychotic effects of cannabidiol (CBD) and cannabigerol (CBG). Some report evidence of panic-attacks and increased depression and others give evidence of the anti-anxiety effects especially in chronic pain conditions, such as Multiple Sclerosis and HIV/AIDS and in Post-Traumatic Stress Disorder. In fact, Veterans Affairs Canada pays for the cost of medical marijuana for PTSD patients.

Much of the contradictory testimony was not included in the majority report. Yet, the vast majority of witnesses pointed to inconclusive evidence, so far, of direct harms and risks and to the need for research on benefits of cannabis; the relationship between cannabis use and long-term brain development and intellectual attainment in youth.

Recommendation 3: The Government of Canada fund research aimed at improving the understanding of the short- and long-term harms and benefits related to marijuana use among all cohorts of society.

It is unfortunate that much of the evidence from credible witnesses that have a differing view of the government is not included in the report. It is also unfortunate that many of the suggested recommendations of many witnesses for further research into the possible medical benefits of cannabis were entirely absent from the Committee’s report.

List of Recommendations:

  1. The Government of Canada explore a regulatory framework of legalization, working with experts in the field that aims to keep marijuana out of the hands of youth.
  2. The Government of Canada work with relevant stakeholders and experts to develop a campaign to raise public awareness and knowledge of the risks and harms associated with marijuana use.
  3. The Government of Canada fund research aimed at improving understanding of the short- and long-term harms and benefits related to marijuana use among all cohorts of society.