Marijuana use can worsen outcomes for young adults with psychosis—how can mental health providers help them stop?

Twelve years after Washington and Colorado became the first states to legalize recreational marijuana, it’s safe to say that weed is here to stay. Nearly 30% of Washington adults report using cannabis in the last month, and a majority of Americans believe marijuana products are safe.

When it comes to the safety of long-term marijuana use among the general population, the jury’s still out. But there are some groups for whom cannabis poses a serious health risk.

Among the most vulnerable are young adults with psychosis, who tend to use cannabis at extremely high rates, and whose symptoms can be exacerbated by long-term marijuana use. A team of University of Washington researchers is focused on this particular group.

To effectively treat these patients’ symptoms and improve long-term outcomes, it’s critical for providers to help young adults stop using marijuana as quickly as possible after their first psychotic episode. But that’s proven tricky. Current best practices aren’t always effective for young adults with psychosis, who tend to use cannabis for different reasons than their peers and who may feel different effects.

That leaves mental health care providers with a difficult problem: How can they best discern why their patients use cannabis, and what’s the best way to help them stop?

UW researchers Denise Walker and Ryan Petros, from the School of Social Work, and Maria Monroe-DeVita, an associate professor in department of psychiatry and behavioral sciences in the UW School of Medicine, studied motivations among this group and then developed a novel treatment method.

A pilot study of 12 people showed the method to be effective, though final results have yet to be published. UW News sat down with the research team to discuss their intervention and why it’s so important to help young people in this group cut down their use.

Cannabis use is increasing across the board, but the numbers are staggeringly high among young adults with psychosis—you cite statistics estimating that 60%–80% have used cannabis at some point in their lifetime. What makes a person experiencing psychosis so much more likely to use cannabis?

Walker: Many people were probably using cannabis before the onset of their psychosis symptoms, because there is strong research evidence that cannabis increases the risk for developing psychosis-related disorders. For those who do develop a psychosis-related disorder like schizophrenia, continued cannabis use impedes the recovery process and makes outcomes worse.

There is still a lot more to learn about the cause and effect of these relationships, but cannabis does seem to have a unique relationship with psychosis.

Petros: In addition, there is some evidence to suggest that people with schizophrenia are more prone to feeling bored than people without schizophrenia. In general, a lot of people use cannabis because they like it, and they find the associated high to be fun.

It may be that people with schizophrenia-spectrum disorders are more likely to use cannabis to have fun and feel good because they are more likely to feel bored and less likely to feel pleasure in everyday activities. But the fact of the matter is, we don’t really know.

Another reason that people use cannabis, in general, is because it facilitates social interactions or provides a shared activity in social settings. Because people with schizophrenia-spectrum disorders have smaller social networks and fewer social engagements, it may be that they use cannabis to facilitate improved social interaction, but here again, we need more research to know with more certainty.

At the heart of all this research is the different health risks of cannabis use for people with and without psychosis or other mental health challenges. What are those differences, and why is cannabis use among young adults with psychosis particularly concerning?

Petros: For people with a psychosis, cannabis use is associated with higher rates of dropping from treatment and decreased adherence to medication. It leads to increased symptoms of psychosis and higher rates of psychiatric rehospitalization. In the long –term, cannabis use increases the risk of poor psychosocial outcomes and diminished overall functioning.

Walker: Essentially, continued cannabis use makes it much harder for young adults with psychosis to take advantage of treatment, make strides in their recovery and, ultimately, get on with having the life they want.

Petros: Another major reason for concern is that not only is cannabis use on the rise, people also have progressively adopted more tolerant attitudes toward cannabis. Cannabis has recently overtaken alcohol as the drug most often used on a daily basis in the United States.

While some people can use cannabis without a problem, it’s recommended that some others abstain from using at all. Over time, however, people have come to believe that cannabis use has health benefits, and they are less likely to perceive risks of use.

This may result in a particularly challenging set of circumstances for helping someone with psychosis to learn about the real risks that cannabis use has for their health and wellness and to make the choice to reduce or abstain from use.

Walker: I agree. Perceptions surrounding cannabis are often polarized—it is often viewed as either “good” or “bad,” when in reality, it’s somewhere in the middle. There can be benefits for some to use cannabis and real risks of harm for others. These mixed messages, or at least the lack of acknowledgement of harm, contribute to continued hardship for those experiencing psychosis and their families.

What methods are currently recommended to help people reduce their cannabis use, and why might those not be as effective for young adults with psychosis?

Walker: The gold standard treatment includes a combination of motivational enhancement therapy (MET), cognitive behavioral therapy (CBT), and contingency management. Contingency management is often not available in the community, and studies show that MET plus CBT perform almost as well.

Because it is normal for motivation to wax and wane for someone contemplating changing their cannabis use, MET addresses the issue of motivation early on. CBT teaches skills to avoid drug use, cope with social situations and negative moods, and solve problems without the use of cannabis. Family therapy is another option with strong support.

The big problem is that we don’t know if these treatments are effective for young adults with psychosis. MET is the most studied intervention in cannabis treatment, alone and in combination; however, it has not been tested with young adults with psychosis. With a few optimizations, we believe that it could perform even better than with the general population, and we have begun to test it with young adults with psychosis.

Your team has developed an intervention for young adults with psychosis that incorporates MET. Can you describe what that intervention looks like, and why it might be more effective for this population?

Walker: MET is a person-centered, nonjudgmental approach that facilitates an honest and candid discussion about cannabis use. The techniques are intended to draw out the individuals’ personal reasons for making a change and to grow their motivation to do so.

Individualized feedback is created based on a client’s responses to an assessment of their cannabis use and related experiences and summarizes information about their cannabis use patterns, how their cannabis use compares with others, and their risk factors for developing a cannabis use disorder.

It also provides an opportunity for clients to think about their personal goals and how their cannabis use promotes or detracts from their ability to attain those goals.

When we asked young adults with psychosis what they wanted in a cannabis intervention, they were clear that they wanted an individualized and nonjudgmental approach. They also said they wanted accurate and science-based information about the relationship between cannabis and psychosis. MET ticks those boxes.

With a few adaptations, it is an ideal format for providing objective information, while also inviting the young adult to talk it through and consider what the information means to them personally.

Currently, providers are giving the message to patients that cannabis is harmful for those with psychosis, which is a great start. But most providers don’t feel confident discussing why cannabis is harmful and what the research has found.

My sense is that patients often take that message and defend against it with their own personal experiences of what they like about cannabis. MET offers an invitation to receive and discuss objective evidence, consider their own experiences of how cannabis affects their symptoms and what they want for their future, and do so in a supportive environment that allows for looking at their use from a variety of perspectives.

You ran a pilot program to understand how the new intervention works. What did you learn in that pilot study?

Walker: We adapted the MET intervention to include personalized feedback on the interaction between cannabis and psychosis and included some graphics and ideas about ways to reduce those risks in addition to abstinence.

Twelve young adults experiencing psychosis who used cannabis regularly enrolled in the study and were offered the intervention. Most of the participants were not interested in changing their use of cannabis at the outset of the study, and by the end, several chose to reduce their cannabis use.

Overall, the feedback was very positive. Participants overwhelmingly said they would recommend the intervention and would retain the psychosis specific pieces of the conversation. They appreciated the data that was included and the opportunity to discuss what it meant for them.

They also said they enjoyed talking about how cannabis fits into their larger life and goals for the future. Overall, the feedback suggests this intervention has promise and should be studied in a larger trial.

Monroe-DeVita: My long-term goal would be to offer this new intervention either in addition to, or integrated within, the evidence-based package of services known to work best for individuals experiencing first episode psychosis.