Chronic Pain the Most Common Reason People Use Medical Cannabis Interview with:

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Kevin Boehnke, Ph.D. Research investigator
Department of Anesthesiology and the Chronic Pain and Fatigue Research Center
University of Michigan  What is the background for this study?

Response: Medical cannabis is legal in 33 states, and people can obtain medical cannabis licenses to treat a wide swath of conditions, including cancer, anxiety, irritable bowel syndrome, chronic pain, complications of Alzheimer’s disease, and nausea. Many observational surveys have found that many people use cannabis for chronic pain, but whether these surveys were representative of national trends was uncertain. To our knowledge, this was the first study that examined nationwide trends of patient-reported qualifying conditions based on medical cannabis state registries. What are the main findings?

Response: This study adds to our understanding in several ways.

First, the majority of conditions for which people use cannabis have substantial or conclusive evidence of cannabis being an effective treatment. These include chronic pain, multiple sclerosis, and nausea and vomiting. To us, this was quite an important finding because medical cannabis is a controversial and polarizing topic, in which some people claim that cannabis is a valuable medicine for many conditions (including many that are not evidence-based) and others claim that cannabis is merely a drug of abuse or recreation, and that medical cannabis laws are simply a cover for potheads to get high legally.

Our findings suggest that many people are actually using cannabis for reasons that are evidence based, and we believe that’s an important contribution to this ongoing societal discussion.

Second, there are still quite a lot of qualifying conditions that have little or no evidence of efficacy that are allowed under many state laws. This reveals how disconnected the policy is from the science.

Third, we now know that chronic pain is indeed the most common qualifying condition for which people obtained medical cannabis licenses. Given the context of the opioid epidemic and the consistent observational studies that report medical cannabis patients substituting cannabis for pain medications, we now have a better sense of how widespread that practice and rationale may be. What should readers take away from your report?

Response: Up until this point, there wasn’t much concrete, nationwide data about why people are using cannabis. There’s still a lot to be learned, but this is a good starting point to build from.

Our results also point to the massive problem of chronic pain. Indeed, chronic pain was the most common reason that people were using cannabis. This makes sense, because chronic pain is incredibly common, affecting tens of millions of Americans.

However, it’s important to note a few things that may complicate this picture and suggest some important future directions as well as limitations of the current study.

First, chronic pain can be both a standalone medical condition (e.g., fibromyalgia) as well as a symptom (e.g., pain related to cancer, Parkinson’s disease, multiple sclerosis, etc…). Because of that, it is possible that some patients listed chronic pain as their qualifying condition, but are also using cannabis for other symptoms or conditions that were not covered under the state law.

Second, many chronic pain medications (e.g., opioids) come with significant side effects, and cannabis is perceived as being relatively safe because the risk of fatal overdose is so incredibly low. Fewer side effects is one of the common reasons in observational studies that patients say that have substituted cannabis for medications, which is consistent with this idea.

Third, it is possible that some people who want to have legal cover for using cannabis recreationally used chronic pain as their qualifying condition because pain is subjective and thus a convenient condition to use to get a license. What recommendations do you have for future research as a result of this work?

Response: We’d like to continue following these data as more state registries come online to see whether the trends we identified here continue. There are many states that recently passed laws but don’t have registries with available data, so it’ll be interesting to see what comes of that. We also want to do a deeper dive into how cannabis and cannabinoids affect different types of pain. To that end, we have some ongoing observational studies where we follow current cannabis users over time, and we are also hoping to do some clinical trials in the future.

Disclosures: : Kevin Boehnke’s work on this article was supported by the National Institute of Dental and Craniofacial Research (Grant No. K12DE023574), and Rebecca Haffajee’s work on this article was supported by funding from the National Center for Advancing Translational Sciences (Grant No. KL2TR002241). Daniel Clauw  has consulted for Pfizer Inc., Eli Lilly and Company, Tonix Pharmaceuticals, Aptinyx, Regeneron, IMC, and Intec. None of the other authors has relevant financial interests in or relationships with entities in the biomedical arena that could be perceived to influence, or that give the appearance of potentially influencing, this article.


Kevin F. Boehnke, Saurav Gangopadhyay, Daniel J. Clauw, Rebecca L. Haffajee. Qualifying Conditions Of Medical Cannabis License Holders In The United States. Health Affairs, 2019; 38 (2): 295 DOI: 10.1377/hlthaff.2018.05266


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Last Updated on April 18, 2019 by