Cannabis legalization is spreading across the U.S. like wildfire. As more users come into contact with the drug, research into its effects is all the more essential. We sat with Assistant Professor of Economics at UNM Sarah Stith—one of the leading cannabis researchers in the nation—to discuss the future of cannabis research.
The Paper.: Why is cannabis research so important?
Stith: I think cannabis research is important because there’s not enough of it. We have all of these states that have legalized medical cannabis or recreational cannabis, and the science is still unsettled. There’s increasing evidence regarding the effectiveness of short-term use. But we still don’t know a whole lot about the long-term use. We can build up what we know anecdotally—we know that people aren’t falling dead from consuming cannabis, for example—but we really don’t have any good medical research on it, because it’s still Schedule I.
We’ve tried to fill this gap to some extent, using observational data as economists, but we rarely get to have natural experiments where we get to test something in one economy or one market but not in another, and so forth. We have a lot of tools for trying to develop causal relationships using econometrics to study observational data, but that’s ultimately all we can get at—quasi-causal relationships.
There does seem to be a lot of evidence that it is extremely effective for a lot of different conditions. We also have additional research that shows that—for example—stock markets respond to cannabis legalization in the sense that the stock market valuation of major pharmaceutical firms goes down. It’s a transitory effect—it dissipates—but it is associated with a loss in sales for pharmaceutical firms. You can translate it often into sales. And there are a variety of other papers not written by me that show that when cannabis becomes legal in a state, there’s a reduction in prescription costs for Medicare and Medicaid.
We have a paper analyzing data from many patients who joined the Medical Cannabis Program here in New Mexico, and we found that they reduced their opioid use and their use of pretty much every other class of drugs as well.
It’s a really powerful substitute on the medical side. There’s some evidence that it could be a substitute for alcohol, and alcohol causes all sorts of problems in our society. I think that there’s definitely some arguments for recreational legalization from that perspective. There’s also a massive illegal market that we could make legal. We could regulate it and make sure that its quality is controlled and that people aren’t getting exposed to pesticides and other additives.
There are efforts at the federal level to make researching cannabis easier for scientists. Have changing attitudes made researching cannabis any easier?
Yes, absolutely. When we first started doing this research, there were very few people doing it. I was looking at these medical cannabis patients who were reducing their opioid use, and we would get these odd calls from people trying to see if we were manipulating our data—asking strange, leading questions. It was really weird. I’ve never had that happen with any other research project.
We don’t get any of that anymore. There’s so many people who’ve now written papers looking at the opioid use issue from all different angles, using all different types of data. I think that it’s become accepted that there are medical uses for cannabis. We don’t fully know what they are yet, or how effective they are, or what the long-term side effects are, but it’s pretty much accepted at this point that there are medical benefits. In fact there’s actually a Pew Research Center survey that came out recently found that 91 percent of Americans support medical legalization.
Are there any areas of study that you feel are being neglected that need more attention?
I think from a medical perspective, the two areas we need to understand better are the long-term effects, and if there’s any negative impacts on developing brains, particularly in adolescents. There’s a lot of correlational evidence, but it’s extremely difficult to get any sort of causal relationship, because people who choose to use cannabis may also choose to do a lot of other things that may be negative. There may be correlation between cannabis use and anxiety and depression, which have negative outcomes on your life. But patients may actually be treating themselves with cannabis and are doing better than they would have if they hadn’t been consuming cannabis. It’s very difficult in these population surveys to figure that out.
What do you think will be the next big area of cannabis study?
Once the government opens things up a little bit more, things will be easier. It seems like even here in New Mexico, there’s new money for cannabis research. There’s money for cannabis research in Colorado. I think it’s going to be more of what has already been done with observational data. That will start being done with randomized controlled trials. I think researchers will really try to narrow in on what aspects of cannabis are helping people. Especially if there are any aspects that can be patented or commercialized at a profitable scale. That would certainly drive innovation, for better or worse.
But I think that when it comes to long-term use—it’s just hard to study. And I think it will gradually get better and people will innovate, but there’s just not going be some sudden turn, and all of a sudden we know everything about it. It’s a really complicated plant.
I’m reminded of a Medicaid paper where they have this huge list of different drug classes, and the use of every single one goes down in states the year after medical cannabis is legalized. And that’s just medical. As you can imagine, there are much bigger effects when you’re talking about recreational cannabis.
I want to look at some of the cannabis tourism using cell phone tracking data to see how cannabis tourism is going, and how it shifts when states legalize. I had the most interesting conversation with the senior UNM faculty member, and he said to me that now that cannabis is legal, he’s going to drive up to Colorado and get some. And I thought, “Well gosh. What was different before?” It’s very interesting to see that that margin alone was enough to get someone to cross the border.