New Study Examines Why THC Produces Negative Effects in Some Users

It’s a scene all-too familiar to stoners. A joint is passed around at a party, shuffling from hand to hand amid a plume of smoke, until it arrives in the possession of a friend who—come to think of it, you’ve actually never gotten high with. And then your learn why: weed, he says, makes me anxious, paranoid. For him, unlike the rest of the party-goers, this is not an escape. 

It can be a confounding mystery to those for whom cannabis elicits pleasure, ecstasy, munchies, non-stop giggles. But now, new research released this month offers crucial insight on those differences. The research, conducted by Western University in Ontario, Canada and published in Scientific Reports, offers a unique window into the disparate effects of cannabis—and more specifically, its chief psychoactive ingredient, tetrahydrocannabinol, or THC—has on the brain.

The researchers used rats to learn how THC can more acutely affect different parts of the brain, discovering that if the front is more sensitive, the results of consuming cannabis will yield more pleasurable effects, be they relaxation or euphoria. But if the back part of your brain is more affected, you’ll likely experience more adverse reactions, such as paranoia or fear.

One of the study’s researchers, Steven R. Laviolette, told Yahoo that the study offers a “very new finding.” 

“There is not too much known about why there is such differences in response to THC,” he says. “We know a lot about the long-term and short-term effects…But there is very little known about the specific areas in the brain that are responsible for independently controlling those effects.”

Laviolette and his colleagues will now begin exploring the possibility of testing the hypothesis on an actual human brain. “Be aware that we’re starting to unravel some of the more intricate details of how cannabis is affecting the brain,” he explains. “Monitor your use and if you’re experiencing negative side effects, talk to your physician.”

The findings can be seen as one of a litany of attempts to fill the void in credible cannabis research. While states across America and countries around the world continue to move toward lifting the longstanding prohibitions on recreational pot use, there remains a remarkable lack in studies on the actual effects of cannabis.

That gap is being closed in part thanks to the research pouring out of Canada. A study released last month out of the Ottawa Hospital Research Institute, for example, found a correlation between cannabis use among pregnant women and preterm birth. In May, the Canadian Institutes of Health Research announced it would be dropping roughly $24.5 million to bolster cannabis research. That funding will support 26 projects throughout Canada “that cover topics such as the use of cannabis and cannabidiol (CBD) oil for the treatment of pain and anxiety,” according to the agency.