A Washington University study seeks to find the link between genes and cannabis use.
The study, which began in 2021 and will run until the end of 2022, is one of the first of its kind, says Nancy Saccone, associate professor in the Department of Genetics.
It hopes to better understand how one’s genes can influence the effects of cannabis on a person — how it can lead to pain relief in some, and negative side effects in others. Down the line, it could help inform cannabis-related treatment or prevention for patients.
“I think it'll be really useful to see that profile of who's using cannabis for different reasons and what proportion of people are saying it's effective for them versus not,” she says.
Saccone, who has worked in the genetics department at Washington University for 20 years, has previously studied how genes affect susceptibility to nicotine addiction. She found strong evidence that genetic variation influences people’s risk of becoming dependent or addicted to nicotine. From there, the data has helped identify who is more likely to stop on their own, or who would benefit from medication to quit smoking.
But recently, Saccone shifted her focus to cannabis, calling it the “natural step,” given its recent attention.
Medical marijuana was legalized by voters in Missouri in 2018, with the first licenses issued in 2020. It allows doctors to use their professional opinion to prescribe marijuana for qualifying conditions such as chronic pain, insomnia, migraines, cancer and more. As of August, there were 197,690 people in the state with active medical marijuana licenses.
“A lot of people use cannabis for medical reasons for some sort of treatment purpose, but today, most [genetic] research doesn't really focus on that,” she says. “When you look at the research literature on cannabis and the kind of [genetic] data that we have, it's usually focused much more on the addictive aspects.”
Unlike traditional, in-person studies, Saccone decided to use an online-only survey. She says participants are sourced online in Reddit groups and cannabis podcasts, for example.
The study requires two steps. First, participants are asked to take a five-minute survey about why they use cannabis (or not).
“We thought it would be good to do a study where we asked people: What are your reasons for using cannabis?” she says. “Are you using it for pain relief? Are you using it to help you sleep? And is it working for you? That data doesn't exist in the [genetic] datasets that I'm familiar with.”
Finally, they’re asked to provide genetic data through Ancestry or 23andMe. When the results are finalized, Saccone and her team will synthesize the results from their questionnaire and ancestry data. The goal, though, isn’t just to find the link between cannabis and genes.
The study is part of a larger effort to use genes to provide better healthcare, Saccone says –– to know that some people, based on their genetic data, would benefit from cannabis and some people would not.
“We’re not there yet,” she says. “I sort of describe it as this holy grail.”