“Someday there’ll be a cure for pain,” the band Morphine once sang. “That’s the day I throw my drugs away/When they find a cure for pain.”
A cure for pain is an impossible wish, and so we still have our drugs. Sometimes, though, those substances we turn to do us more harm than good. We can see this clearly enough in the streets of our cities, where powerful opioids contribute to an ongoing overdose crisis.
What if there existed not a cure for pain but something that could help assuage it without the deadly risk?
A growing body of research seems to point to cannabis as a means by which opioid users can decrease their dependence on more harmful drugs.
A cluster of intractable problems
Dr. M-J Milloy is a research scientist at the B.C. Centre on Substance Use. He is also the Canopy Growth professor of cannabis science at UBC.
Milloy tells CannCentral that the main focus of his research is trying to determine what beneficial role cannabis might play in the overdose crisis.
“The overdose crisis is driven by illicit opioid use,” he says, “which is often a reaction to pain, to unaddressed trauma, to depression and anxiety, and indeed to dependence itself. It’s sort of a cluster of really intractable problems.”
Milloy has co-authored several studies on the relationship between illicit opioid addiction and cannabis use. The American Journal of Public Health published the most recent of these on August 20.
“We have three studies of people who use drugs in Vancouver,” Milloy explains. “Two are studies of adults in the Downtown Eastside primarily, and one is a study of youth, primarily in the Downtown South area. And in the AJPH study, we looked at their injection cessation and injection relapse behaviours.”
A strong negative relationship
Milloy’s team interviewed 2,459 subjects every six months between 2005 and 2018. The researchers found that, during periods when subjects were using cannabis every day, they were 24 percent more likely to have stopped injecting opioids during that same period.
“And this is consistent with some other work that we’ve done looking at the relationship between illicit opioid use and cannabis use among people in those studies, looking at pain,” Milloy tells CannCentral. “Again, we found there was a strong negative relationship; again, the more people were using cannabis, the less likely they were using illicit opioids.
“Similarly, in a study of people who were at risk of beginning to inject drugs, we found that if they were using cannabis every day, they were far less likely in that six-month period to initiate injection-drug use. This is very consistent with other studies, and indeed qualitative studies, in which people tell us, ‘Yeah, I turn to cannabis as a way to try to moderate or modulate or control my other drug use.’”
The reverse gateway
In early August, CannCentral reported on a peer-reviewed research paper published in the medical journal PLOS One. Milloy was one of the authors of that study. It looked at how street-involved young people use cannabis as a method of harm reduction.
Researchers interviewed 56 young people in Vancouver between 2017 and 2019. The majority of study participants engaged in “daily, intensive cannabis use”. During the same period, they cycled on and off alcohol, fentanyl, heroin, and other substances perceived as more harmful.
The authors wrote that most participants derived significant pleasure from the use of cannabis. However, no participants in the study described using cannabis for purely recreational purposes.
Instead, participants framed cannabis use as a form of mental-health and substance-use treatment.
The authors write that their findings demonstrate what one could refer to as a “reverse gateway effect”. Among some street-entrenched youth, “cannabis use was associated with the intermittent reduction, elimination or prevention of more harmful forms of drug use such as meth and opioid use.”
Cannabis as an exit ramp
Scarlett Nelson is peer research associate with BCCSU’s At-Risk Youth Study. She co-authored the PLOS One study. According to a BCCSU news release, Nelson was diagnosed with attention deficit hyperactivity disorder and oppositional defiance disorder as a teen. She said doctors prescribed her a “cocktail” of medications to treat the disorders.
When none of these worked, however, Nelson turned to illicit substances, including meth and heroin, to treat her conditions. Eventually, according to the press release, she obtained an authorization for medical cannabis. She credits this with helping her stop using illicit substances altogether.
“Cannabis, for me, was an exit ramp from using other, more dangerous drugs and helped make me feel better overall,” she said.
Milloy says stories like Nelson’s are not uncommon.
“Certainly in the Downtown Eastside there are people who tell us that they do employ cannabis as a sort of harm-reduction intervention,” he says. “So what we’ve been trying to do is, quite simply, learn more about this so that we can try and run experimental trials to really provide better evidence about whether this is an effective strategy, and what the risks and benefits might be.”
The conventional wisdom
Where pain relief is concerned, doctors prescribe opioids in mass quantities because they work better than anything else. Or at least that’s the conventional wisdom.
There is a body of research suggesting that substances found in cannabis—including THC and CBD—have analgesic and anti-inflammatory properties. Cannabis use, moreover, does not carry the side effects or the inherent risks that opioid use does.
“Addiction is obviously a problem with both,” Milloy allows. “However, I certainly believe that dependence on cannabis is less severe and less pervasive than opioids.
“Similarly, obviously, the big thing—overdose,” he continues. “As we all know, it’s quite easy to overdose on opioids. It happens, of course, in our community and many others every day. With cannabis, with THC, we pretty much think that that’s impossible. The parts of our brain that control our breathing and such are pretty well segregated from the parts of the brain that cannabis interacts with, unlike opioids.”
Severe regulatory barriers
Why, then, is there not even more research being done into cannabis as a means of pain relief? Milloy says that, in part, it’s because there are “severe regulatory barriers” in place that make things difficult for scientists.
“In particular, what we’re finding is that Health Canada wants those of us who want to do this sort of research to provide background safety data on the types of cannabis that we would like to use,” he says. “It’s very difficult to generate this data. We would argue that it’s a bit of a weird position, because at the same time Health Canada has approved these very same substances for adult use in the recreational market.
So we’re saying, ‘Look, guys, you’re saying that it’s okay for someone to walk into a shop and buy this. Yet in a very controlled, safe, medical environment, we need to provide all sorts of background pharmacokinetic safety data for us to be able to do something that Canadians are already doing.’ So it’s a bit of a frustrating position.”
Milloy remains hopeful that the science will get done, though. It must. As he said upon the publication of his team’s most recent study, it’s about saving people’s lives.
“These findings underline the need for researchers to test the life-saving potential of cannabis during this public health emergency,” he said at the time. “Meanwhile, our policymakers should make sure they are facilitating access to cannabis as harm reduction by, for example, reducing barriers to legal cannabis or supporting community groups distributing cannabis to people at risk of overdose. Our findings suggest using cannabis for harm reduction has the potential to save lives.”