It is often accused of being a gateway drug, but new research is now pointing to marijuana as an exit drug.
It’s an issue that’s become particularly relevant as Canada and an increasing number of states in the US continue to relax their laws around pot, giving more people access to the drug and, so the claim goes, more likelihood that they might move onto to other drugs with more serious health consequences.
There is truth to the idea in one minor sense. Marijuana is often the first illicit drug that people try during their teen years, and thus, going by timeline alone, for those people who do end up using hard drugs, pot can sometimes precede harder drug use. But by that logic, the same could be said for tobacco and alcohol.
In reality, research has not borne out the case. While some studies involving rodents have found that exposure to cannabinoids increases their behavioural response to other drugs like heroin, an effect called cross-sensitization, experts have concluded that the factors contributing to a person’s drug use and addiction are many, involving not only physiological but environmental and social elements, as well. Thus, it’s difficult to put a lot of causal weight onto this one factor. And, again, other drugs like nicotine and alcohol also create cross-sensitization.
Even in the United States where a hardline position on pot has been the historical norm, then-Attorney General Loretta Lynch spoke last year on the opioid crisis in the US and admitted that marijuana is not a gateway drug but that prescription painkillers are. And in a lengthy review of the science almost two decades ago, the US Institute of Medicine of the National Academy of Sciences drew the same conclusion, saying, “There is no conclusive evidence that the drug effects of marijuana are causally linked to the subsequent abuse of other illicit drugs.”
Marijuana as an exit drug…
But research is growing that pot could function in the opposite way, as an exit drug helping users of harder drugs break the habit. A 2011 study, for instance, found that cocaine-addicted mice who were given a synthetic cannabinoid reduced their cocaine intake by up to 60 per cent. And a 2014 comparison of opioid overdoses in the US found that between 1999 and 2010, states with medical cannabis laws had a 24.8 per cent lower annual opioid overdose mortality rate than those without such laws, suggesting that pot use has an effect on opioid use.
Now, a study from the BC Centre on Substance Use has found that crack cocaine users may also benefit from having access to marijuana. Researchers interviewed people who use illicit drugs in Vancouver’s Downtown Eastside and found that those who intentionally used cannabis to reduce their use of crack cocaine were able to significantly lower their crack use.
“We were a little bit surprised when we found out people were reporting that they were substituting cannabis for crack cocaine,” said Dr. M-J Milloy, research scientist at BCCSU and study co-author, to MetroNews. “We expected that the drug that they would be substituting for would be heroin or some opioid because both share pain relief properties.”
The researchers see the results as promising, as while drug therapies like suboxone and methadone can be used to treat heroin addiction, currently there are no effective pharmacological treatment options for people addicted to crack cocaine.