As a scientist working to improve the health of people living with HIV/AIDS who use illicit drugs, I'm reminded every day of the impacts of our government's policies on drugs. What's more, I have seen how misinformation about drugs can lead to ineffective and even harmful drug policies.
My own work involves researching the potential impact of cannabis among people living with HIV/AIDS. Patients have told us for decades that marijuana helps them deal with the side effects of their medications. But now, in a preliminary study, we have found evidence to suggest that people who use cannabis are more likely to have slower HIV disease progression -- meaning that they can live longer and healthier lives. That finding is likely due to cannabis' anti-inflammatory properties, which slows the replication of cells carrying the virus in a person's body. It's a surprising outcome, but one that helps us better understand a possible role for cannabis in viral infections. But in the current political climate, I'm continually coming up against claims by our political leaders that expanding adult access to legal, regulated cannabis would be an unmitigated disaster. Statements like these make it harder for me to do my job as a scientist.
In Canada, cannabis is widely available and levels of use appear to be surprisingly static. In 2012, 41 per cent of Canadians reported ever using cannabis, while 43 per cent reported using it in 2002. Which means that many Canadians have firsthand experience with the drug, and many others have an opinion on it. What is troubling, though, is that while the scientific evidence on cannabis is growing rapidly, non-scientific claims about the impact of cannabis on the body are continually repeated in headlines, online, and by policymakers -- to the point that they begin to sound true.
Interpreting scientific evidence isn't always an easy task: it involves assessing a massive set of studies and sometimes coming up against competing findings. Take the issue of potency, for example, which is in the news again with the Canadian federal government's recent anti-cannabis television advertisements. These ads claim that cannabis potency has increased on average by up to 400 per cent from a few decades ago. Unfortunately, the issue is just not that cut and dry. Data from the U.S. government suggests that on average, cannabis potency has increased from about three per cent in the 1980s, to 12 per cent in 2012 -- a 300 per cent increase. What about Canadian data? Well, government spokespeople have referred only to U.S. data, so we don't really know what the situation is in Canada.
Lost in this debate around potency, though, is a basic but important question. Does increased potency actually have a detrimental effect on the body? Unfortunately, this seems to be another case where the evidence is mixed, at best. In the short term, high-potency cannabis can lead to dangerous levels of intoxication, although without the overdose-type effects of alcohol or opioids like heroin. The impact of long-term use is frustratingly elusive, and scientists who have reviewed the evidence have flatly stated that these concerns over potency are not supported by the science.
Even if we assume increased cannabis potency is problematic, though, what is the best way of controlling it? Between the 1980s and the 2000s, when U.S. cannabis potency increased by about 300 per cent, the U.S. government engaged in a massive global program to reduce cannabis supply. Clearly, it was a failure. In comparison, when a Canadian medical cannabis supplier accidentally released a strain of cannabis with THC levels of 14 per cent earlier this year (it was labeled as nine per cent THC), Health Canada took a simple step: it recalled the product from the market. Just like that, the higher-potency cannabis was off the market, something the U.S. government couldn't achieve despite investing billions of dollars and deploying the world's largest counternarcotic force.
We expect our political leaders to build policies based on the evidence so that they are as effective as possible. Drug policies should be no different. Unfortunately, Canada's current policies on cannabis are based on a misreading of the science. Worse, they are making it harder for people to access life-saving medicine.
For more information on the scientific evidence behind oft-repeated claims about cannabis use and regulation, check out the International Centre for Science in Drug Policy's latest reports and ongoing campaign for evidence-based cannabis policy. Make sure to sign up for their newsletter so you never miss an update.
M-J Milloy, PhD, an infectious disease epidemiologist, is an assistant professor in the Department of Medicine at UBC, a research scientist with UHRI and the Principal Investigator of the Aids Care Cohort to Evaluate Access to Survival Services (ACCESS), an ongoing prospective cohort of approximately 1,000 individuals living with HIV/AIDS who use illicit drugs. His research focuses on identifying the social and structural factors associated with HIV disease progression and suboptimal HAART outcomes among members of vulnerable populations.
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