Over the last few decades, public perception and attitudes toward marijuana have evolved. It’s become much more widely accepted, both socially and in the legal landscape. Two dozen states and the District of Columbia having legalized recreational marijuana use. And on the federal level, the Biden administration is moving forward with efforts to move cannabis from a Schedule I classified drug — alongside drugs including heroin and LSD — to a Schedule III drug.
New research reveals these changes align with a change in behavior. Scientists at Carnegie Mellon University analyzed 40 years of data and found that daily marijuana use is surpassing alcohol consumption in the U.S.
Dr. Staci Gruber, director of the Cognitive and Clinical Neuroimaging Core and the Marijuana Investigations for Neuroscientific Discovery program at McLean Hospital, joined GBH’s All Things Considered host Arun Rath to discuss these findings. What follows is a lightly edited transcript.
Arun Rath: I want to get your reaction to this study before we dig into the specifics. Were you surprised to hear these findings in terms of what appears to be an increasing use of marijuana?
Dr. Staci Gruber: So, you know, I think when we think about public perception and attitudes and change across the nation, really, cannabis use has become much more widespread. End of story, you know, full stop, mic drop — right? We know that. It doesn’t surprise me that so many people are reporting use [at] a daily or near daily rate at this point. It doesn’t surprise me.
Rath: As much as you can say for the reasons, is [the jump in usage] simply about accessibility?
Gruber: You know, I think a lot of individuals are interested in exploring different types of experiences now that things are more widely available. I’ve heard a number of people say, you know, “It was one thing when it was illegal. Now that it’s legal, I’d like to have another option relative to something like alcohol to ‘take the edge off’ or have fun with my friends. I’d like to experience these kinds of things.” I think that’s one thing.
When we think about daily or near daily use, we don’t necessarily know from that particular publication what the reason or goal of use was, right? I didn’t necessarily see much about that. I’m not clear that we were absolutely sure of why individuals were using daily or near daily.
I would just remind everybody that when people are using cannabis or cannabinoids for medical purposes, they are often using daily or near daily, just as they would use any medication. That’s an important consideration.
I think, sometimes, some of these studies — especially survey studies — while they give you a little information on a lot of people, it’s very challenging to sort of drill down and understand certain important aspects without more specific data. For one thing, I’d love to know how many people reported their use of daily or near daily use of cannabis that were using for medical versus sort of adult recreational purposes. That’s a really important distinction.
Again, when we think of the sheer number of people who report using for medical purposes — or at least in part for medical purposes — those folks will clock in at daily use because, again, like they’re using anything for high blood pressure or any other condition or indication, they often use their cannabis or cannabinoid products on a daily basis.
Rath: How important is it to consider the increase in potency of the available marijuana now?
Gruber: That’s a great question. So, we’ve certainly seen quite a shift when we think about potency. Again, Delta-9 THC or THC content is generally sort of a marker, if you will, for potency. How intoxicated one might be is generally a reflection of the products that they’re using or how much they’re using.
Average potency has increased exponentially over the last several decades. The national average is somewhere around 16% or 17% THC. Years ago, it was, you know, 4%, 5% or 6%. So that’s a big consideration.
We also have products that are designed to deliver, let’s just say, a bigger bang for the buck, right? These so-called concentrates start at, like, 30% or 40% THC and go north of there, all the way beyond 90%. It does make a difference.
It makes a difference with regard to what individuals — whether they are recreational consumers or medical patients — actually expect versus what they get. That’s an important consideration as well.
Some people will tell you that they can titrate their use. So if it’s a much stronger product, so to speak, they use a lot less. Some will say, you know, “I use about the same amount no matter how potent it is.” So one, then, would be mindful of the potential outcome and the potential negative effects associated with that.
But in this particular case, I would remind everybody that age matters. When we think about adolescents or emerging adults with neurodevelopmental vulnerable brains ... we’re likely to see a more significant negative impact than for individuals who are mature — that is, they are adults, and brain development is largely done. That’s another very important consideration.
Rath: And for adults — if we put aside for the moment the potential benefits of cannabis — in terms of daily use in what you’ve seen in patients, what could be the problems that could come up with daily use?
Gruber: I think, again, it’s a different sort of set of issues or concerns, whether you’re in the adult recreational space or the medical space. But, regardless, the interesting thing is: cannabis is complex. It’s this miraculously complex plant, right, [containing] over 400 or 500 compounds. A hundred of these are phytocannabinoids — things that interact with your own endocannabinoid system or system of chemicals and receptors throughout the brain and body.
The plant doesn’t care what you use it for, right? It doesn’t care. And the truth is, even people who are using medically should be mindful of the potential negative effects, right? So potential drug interactions, if you’re taking certain classes of medications, we want you to be mindful. Certain cannabinoids can really disrupt the levels of other medications that you have on board.
On the recreational side, we’re always mindful, again, of our most vulnerable consumers — so adolescents and emerging adults who are not mature with regard to brain development, individuals who have a predisposition or a genetic liability for psychiatric conditions or symptomology, individuals who are pregnant, things like this. There are a lot of different areas to be mindful or concerned about.
Even the people who are using [marijuana] ostensibly to address symptoms or medical conditions should be mindful of the potential negative effects if they’re not careful about what they’re using and knowing what’s in their weed, if you will. “Know before you go” is what I always like to say. What are you looking for? That is going to dictate the product choice, and the product choice is going to dictate the outcome because it’s all about what’s in your weed.
Rath: You talked about how much we still don’t know — how much data we still really need. On the legal side, moving it from a Schedule I substance — if that happens — will that make it easier for researchers like you to find out the information you need to find out?
Gruber: That’s a great question. You know, I always think it’s a really important thing to remind everyone that rescheduling is not descheduling. What a difference one letter makes, right?
By definition, Schedule I means [the drug has] no accepted medical value. Schedule III, of course, is an acknowledgment that there is, in fact, some medical value.
The administrative hurdles that many of us have had to deal with for many, many moons in terms of getting a Schedule I license at both the state and federal levels. We have tremendous security requirements in terms of monitoring, surveillance and storage. I have a safe that’s as big as, you know, a minibus, basically.
Often, for products that are completely non-intoxicating, it’s really interesting, but certain things will become a little bit easier. We don’t have some of those same hurdles. In certain states, there are state-based groups that you have to clear before you can start any study. Those things will be easier.
On the other side, for our consumers and our patients, nothing really changes. Schedule III — it’s still a scheduled substance, so it’s not that you can go anywhere and everywhere and get this product. We would still have to have a Schedule III license to do these studies, so I think it changes the burden.
And for people looking to get hooked into the cannabis research game, it’s less onerous. But, I think, largely, the rescheduling impacts [the cannabis] industry, and also signals to the nation at large that there is a potential medical benefit, where we don’t see that in a Schedule I.
