Mental Health in a Cannabis Nation

Drew Ramsey, MD; Deborah S. Hasin, PhD


July 11, 2019

This transcript has been edited for clarity.

Drew Ramsey, MD: Welcome back to our coverage of the American Psychiatric Association annual conference, where we're celebrating 175 years of psychiatry.

We wanted to focus on cannabis right now. I'm with Dr Deborah Hasin, a professor of epidemiology in psychiatry at Columbia University, and one of our experts on understanding what's happening in terms of cannabis and substance use in America.

It feels like I'm getting an incredible number of questions in my practice, as I know other clinicians are, about cannabis and cannabidiol (CBD)—whether they can use it and whether it works. Can you tell us what's changing in that area?  

Deborah Hasin, PhD: There are a lot of things changing, actually. If you think back to 30 years ago, there were no states that had legal marijuana use, either for medical or recreational purposes. If you fast-forward to today, two thirds of US citizens now live in states that have legalized medical marijuana and about 25% in states that have legalized recreational marijuana. The number of Americans who think that marijuana is a harmless substance has gone up sharply in the past several years.

It's certainly a point worth making that while a lot of people can use marijuana safely without harm, just as with drinking alcohol, cannabis is not a risk-free substance. There are risks involved in using it, and we see time trends for some of those risks increasing as the number of Americans using cannabis rises.

Not a Risk-Free Substance

Ramsey: What are the big risks that clinicians need to be aware of? Because I'm often surprised that this doesn't get discussed as much as I would think.

Hasin: One of the things that is perhaps most obvious, but that not everybody knows about, is the risk for cannabis use disorder. People assume that cannabis is not addictive. Although it may not be as addictive as opioids, for example, there still is a full syndrome of cannabis use disorder, including cannabis withdrawal, which is included now in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The number of Americans driving under the influence of cannabis is also increasing, which has risks for vehicle crashes. We have new findings coming out that in people with pain, nonmedical cannabis use is increasing, and the association is growing stronger over time. And there is a relationship between using cannabis and developing psychosis, especially among people who have risk factors like a family history of those kinds of problems.

Ramsey: In terms of us screening and trying to better partner with patients, it feels that as a field, we've been very risk-averse and really want to focus on the problems. Yet that's a little out of step with where the public is and where our patients are sometimes. How do you recommend that we talk about the risks, especially when it comes to psychosis?

Hasin: I think acknowledging that cannabis isn't a horrible substance for everybody is a good starting point, because then it's acknowledging that there is some room for discussion. But then saying something about the risks and having a meaningful discussion about what those might be could be a good way to at least get a conversation started. 

Latest on Patterns of Use and Effects on Mood Disorders

Ramsey: You noted that a quarter of Americans live in states where they have access to legal recreational cannabis. That's a huge amount going out into the population. What do you think is going to happen in those states?

Hasin: That's a great question. There haven't been that many years of data available for recreational marijuana laws, because the first ones were only passed in 2012. So in terms of national data, that's not that many years. My colleagues and I have a paper that's under review now. The findings in that show that cannabis use overall in adults, frequent use, near daily use, and cannabis use disorder have increased more in states that enacted recreational laws than in other states. So it suggests that these laws are having an impact.

Ramsey: We talk a lot about the risk in psychotic disorders, but there's also an effect in mood disorders and comorbidities with other substance use disorders. And for many years, marijuana was framed as this gateway drug. Can you tell us about other disorders and also whether in some ways it does facilitate people getting into other substances?  

Hasin: There's a lot of controversy about that last point. Certainly in adolescence, we started to see a switch over 4 or 5 years ago with tobacco no longer being the first substance used by teenagers but cannabis being the first substance used. So now people worry about an effect of cannabis acting as a gateway to tobacco.

In regard to other psychiatric disorders, like depressive disorders, if you look at the diagnostic criteria for cannabis withdrawal, a lot of those symptoms are almost exactly the same as symptoms of major depressive disorder. Sometimes people could be using cannabis, thinking that it's self-treating depression, and what they may actually be experiencing, if they're using cannabis every day, is that when it wears off, they start to get withdrawal symptoms and it feels like depression. So they use it and those symptoms go away, but they may actually be perpetuating an ongoing withdrawal syndrome. That's something else for clinicians to think about.

Ramsey: Thank you so much for all of this great information about some of the big changes that are happening in all of our clinical practices, where patients have increasing access, increasing use, and changes in use patterns of cannabis, and the potential risks associated with that. Again, I think we should be encouraged to be flexible when we meet our patients and understand that there are people who can tolerate this and others who can't. On the clinical side, it's our job to distinguish who's who and do our best to get people toward health. Thank you so much.

Hasin: You're very welcome.

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