Medical Marijuana: More Questions than Answers

Abstract

With 23 states and the District of Columbia having enacted medical marijuana laws as of August 2014, it is important that psychiatrists be able to address questions about medical marijuana from patients, families, and other health care professionals. The author discusses the limited medical literature on synthetic cannabinoids and medical marijuana. The synthetic cannabinoids dronabinol and nabilone are approved by the United States Food and Drug Administration for nausea and vomiting associated with cancer chemotherapy and appetite stimulation in patients with wasting diseases such as acquired immunodeficiency syndrome (AIDS). Results of clinical trials of these agents for other conditions have varied widely thus far. In addition, few data are available on the use of the marijuana plant as a medical treatment. The author concludes that there is a clear need for additional research on possible medical uses of cannabinoids. He notes that discussions with prospective medical marijuana patients should emphasize the importance of communication among all parties due to the possible side effects of treatment with marijuana and its potential to interact with other medications the patient may be taking. Facilitating a thorough substance abuse consultation is one of most positive ways that psychiatrists, especially addiction psychiatrists, can make an impact as medical marijuana becomes increasingly common. A careful review of the prospective medical marijuana user's substance use history, co-occurring medical and psychiatric conditions, family history, and psychosocial stressors is essential in evaluating the potential risks of medical marijuana for these patients. The author concludes that psychiatrists can have a significant impact by increasing the likelihood that medical marijuana will be used in a safe and responsible way.

Medical marijuana is here to stay. Despite strong science demonstrating the potential dangers of regular marijuana use and the absence of endorsement of medical marijuana by any major medical organization,^1,2 Pandora's Box is now open. As of August 2014, residents of 23 states and the District of Columbia have voted to enact medical marijuana laws.³ As medical marijuana is implemented, the controversy surrounding the topic has fostered considerable uncertainty. A heated debate on the merits of the legalization of marijuana is ongoing as well, with both Colorado and Washington State legalizing the recreational use of marijuana. It is important, therefore, for psychiatrists to ask a number of key questions and be prepared to address those questions when raised by patients, families, and other health care professionals in states with medical marijuana.

Does the medical literature support marijuana as medicine?

The synthetic cannabinoids dronabinol and nabilone are approved by the United States Food and Drug Administration (FDA) for both nausea and vomiting associated with cancer chemotherapy and appetite stimulation in patients with wasting diseases such as acquired immunodeficiency syndrome (AIDS).^4,5 However, although many clinical trials have been carried out, evidence supporting the use of synthetic cannabinoids for other medical conditions is equivocal.⁶ In addition, few data are available on the use of the marijuana plant as a medical treatment. The dearth of evidence backing the therapeutic potential of synthetic cannabinoids beyond their current indications, coupled with the health and addiction risks of marijuana, has dampened enthusiasm for clinical trials of the marijuana plant as a medicine. While some patients are hopeful about anecdotal reports of marijuana's effectiveness for a variety of maladies, there are few data to support the use of marijuana for the numerous illnesses patients hope it will treat. However, there is clearly a need for additional research on possible medical uses of cannabinoids.

My patient has read a considerable amount about medical marijuana and has decided that he wants to try it as a treatment for his cancer pain. What do I do next?

Patients who want to try medical marijuana after a thoughtful exchange about its risks and purported benefits, as well as the risks of alternative medications, will need a recommendation from a physician to obtain a medical marijuana card. If, as a psychiatrist, you are not comfortable making such a recommendation, you should defer to the physician, often a specialist, who is treating the debilitating condition that the medical marijuana is intended to treat. Discussions with prospective medical marijuana patients should emphasize the importance of communication among all parties due to the possible side effects of treatment with marijuana and its potential to interact with other medications the patient may be taking.

A patient with posttraumatic stress disorder (PTSD) says that antidepressants have not alleviated her symptoms and she would like to try medical marijuana as a treatment for PTSD. What key points should you address in your conversation with her?

While some promising research supports exploration of the use of cannabinoids as treatments for psychiatric disorders such as PTSD as well as obsessive-compulsive disorder and anxiety disorders,^7--9 more research is needed before psychiatrists can safely and reliably prescribe this family of medications for these disorders. In addition, extensive research would be required before medical marijuana could be considered as a treatment for these disorders. The marijuana plant itself has thus far been studied in only a limited number of clinical trials,¹⁰ underscoring the risk of recommending marijuana, a substance not regulated by the FDA, as a treatment for your patients.²

A patient told me that a loved one wants to use medical marijuana, but my patient worries that it is not for the right reasons. How do we assess for possible addiction?

While most people who use marijuana do not become addicted to it, about 9% of adults and about 17% of adolescents who use marijuana develop problems with addiction.^11,12 These people can experience problems in multiple important areas of their lives, including school, work, and relationships. Facilitating a thorough substance abuse consultation is one of most positive ways that psychiatrists, especially addiction psychiatrists, can make an impact as medical marijuana becomes increasingly common. Patients and colleagues will ask for our opinions on the appropriateness of prospective patients for medical marijuana. This is also a reason that psychiatrists should not turn away from this issue or the patients who raise it. A careful review of the prospective medical marijuana user's substance use history, co-occurring medical and psychiatric conditions, family history, and psychosocial stressors will be essential in evaluating the potential risks of medical marijuana for these patients.

May a patient use medical marijuana while receiving treatment from you?

Federally funded programs are restricted from allowing their patients to use medical marijuana on their premises, as the United States Drug Enforcement Agency still categorizes marijuana as a Schedule I controlled substance with high abuse potential and no currently accepted medical use.¹³ As a result, programs receiving federal funding have not allowed medical marijuana in their facilities for fear of losing their federal support. However, a respectful conversation between patient and provider can lead to the patient agreeing to either forgo the use of medical marijuana or to allow for a temporary substitution with an alternative medication like dronabinol or nabilone, especially during an inpatient program.

Conclusion

With medical marijuana being new to many states, there are more questions than answers about how it will affect our communities. Each state with medical marijuana laws may address important issues related to the laws differently.¹⁴ Many of our colleagues see medical marijuana as an unwanted problem in our busy practices and programs. I challenge our field to look at this as an opportunity to educate our patients on one of the most misunderstood drugs available. With millions of marijuana users in the United States today and that number likely to increase,¹⁵ psychiatrists can make an impact by increasing the likelihood that medical marijuana will be used in a safe and responsible way.