Knowledge gaps: risks and benefits of cannabis for psychiatric patients
Much of the foregoing discussion has focused on the 2 compounds in herbal cannabis that have received the most research attention and have also been of greatest clinical interest: THC and CBD. There are, however, numerous other compounds that are unique to cannabis. The concentrations of these compounds vary widely among the genetically different strains of cannabis and the conditions under which the plant is grown. At this point, we have insufficient research on cannabis and its constituent cannabinoids and terpenes to fully understand its potential to help or harm psychiatric patients and therefore guide clinical practice.
Many states with medical cannabis dispensaries have “counselors” who help guide patients to find the strain of cannabis most likely to benefit the patient’s symptoms. While such guidance is an imprecise proposition and there is substantial subjectivity in whether a given variety of cannabis will reduce symptoms, there are some generalities that guide dispensary counselors in their decisions about cannabis strain selection.
Most medical cannabis is from the Cannabis sativa plant, the Cannabis indica plant, or a hybrid variety derived from cross-breeding the two. Broadly speaking, the conventional wisdom is that marijuana and its extracts from Cannabis indica tend to be more sedating and produce more muscle relaxation than those from Cannabis sativa varieties, and patients with anxiety, insomnia, and chronic pain are frequently steered toward those strains. However, named strain variations are not the only source of self-selection of specific varieties of cannabis by patients. Many medical dispensaries offer laboratory analyses of the major cannabinoid concentrations in the cannabis they sell. As with the products mentioned above, the primary cannabinoid compounds of interest have been THC and CBD, but there are others of potential interest.
The medical cannabis patient and the practicing psychiatrist
Psychiatric patients may use medical cannabis to ameliorate their symptoms, either while in active psychiatric treatment or as a “more natural” alternative. If they are in active psychiatric treatment, they may be receiving additional pharmacotherapy. The astute clinician would want to know the details of the patient’s cannabis use; be alert for adverse effects and potential drug interactions; openly discuss the strengths and weaknesses of cannabis use in psychiatric treatment; and follow the emerging literature on its potential effect on psychopathology, treatment outcomes, and long-term prognosis.
Patients may feel stigmatized not only by their mental disorder, but also by their cannabis use, and may be reluctant to discuss it with their provider for fear of being denied treatment or labeled a substance abuser in need of rehab. Open discussions between psychiatrist and patient about the patient’s cannabis use can potentially be beneficial, especially if the psychiatrist is receptive to learning about the perceived benefits of using cannabis.
Physician advice on reducing smoking and alcohol consumption has a real impact on patient behavior. Perhaps an open and stigma-free discussion about the frequency of cannabis use and the dosing and composition of cannabis might reduce the subsequent risk for a cannabis use disorder or a psychotic break. Actual therapeutic benefit from cannabis use for any given patient might help to minimize total psychotropic medication burden, decrease reliance on opioid analgesics, and/or decrease or eliminate alcohol use. The challenge for modern psychiatry is to recognize the widespread use of cannabis in our society, to advocate for research that fills in our knowledge gaps, to recognize that there are both risks and benefits for psychiatric patients, and to acknowledge that patients need to discuss their cannabis use with their psychiatrists without shame or fear.
MORE ABOUT Christopher G. Fichtner, MD
Dr. Fichtner is a Clinical Professor of Psychiatry at the University of California, Riverside School of Medicine, and a staff psychiatrist with the Riverside University Health System—Behavioral Health. He received his medical degree from The University of Chicago Pritzker School of Medicine (1987). Dr. Fichtner is a diplomate of the American Board of Psychiatry and Neurology and a Fellow of the American Psychiatric Association, with specialty certification in administrative psychiatry. In addition, he is a Fellow of the American Association for Physician Leadership and a past President of the American Association of Psychiatric Administrators. His work in federal (VA), state, and county public mental health systems included a stint as Illinois State Mental Health Director (2003 to 2005), which shaped his views on drug policy.
In 2010, Well Mind Books published Cannabinomics: The Marijuana Policy Tipping Point, in which he argued that impending large-scale policy change was evident in 3 converging policy trajectories: growing consumer demand for medicinal cannabis access (medical marijuana); increasing recognition of drug war failure, especially as it relates to widespread cannabis use (public health); and the increasingly apparent economic potential of a socially integrated cannabis industry (legalization).
In Cannabinomics, he intimated that marijuana policy reform would likely be associated with public health benefits—especially through naturalistic substitution of cannabis for alcohol. Examples of patient use of cannabis as an alternative to opioid analgesics also featured prominently in the book. Emerging data—cited briefly in his article with Howard Moss, MD, in this issue of Psychiatric Times—support the view that marijuana policy liberalization holds potential as a partial solution to the opioid crisis.
Dr. Fichtner’s media appearances in connection with his book have included interviews with Dylan Ratigan (MSNBC), Paul Eggers (First Business, PBS), Bill Moller (WGN Radio), and Brad Pomerance (Charter California Edition).
In 2016, Dr. Fichtner received the UCR School of Medicine Psychiatry Education Service Award.
Dr. Fichtner reports no conflicts of interest concerning the subject matter of this article. Dr. Moss reports that he owns 24 common stock shares of GW Pharmaceuticals currently valued at $2900 in his IRA. GW Pharmaceuticals is the maker of the drugs Sativex and Epideolex.
Dr. Fichtner and Dr. Moss are Clinical Professors of Psychiatry at the University of California, Riverside School of Medicine.
1. Walsh Z, Gonzalez R, Crosby K, et al. Medical cannabis and mental health: a guided systematic review. Clin Psychol Rev. 2017;51:15-29.
2. Grant I, Atkinson JH, Gouaux B, Wilsey B. Medical marijuana: clearing away the smoke. Open Neurol J. 2012;6:18-25.
3. Committee on the Health Effects of Marijuana: An Evidence Review and Research Agenda; Board on Population Health and Public Health Practice; Health and Medicine Division; National Academies of Sciences, Engineering, and Medicine. The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research. A Report of the National Academies of Sciences, Engineering, and Medicine. Washington, DC: The National Academies Press; 2017.
4. Leweke FM, Piomelli D, Pahlisch F, et al. Cannabidiol enhances anandamide signaling and alleviates psychotic symptoms of schizophrenia. Translat Psychiatry. 2012;2:e94.
5. Schwarcz G, Karajgi B, McCarthy R. Synthetic delta-9-tetrahydrocannabinol (dronabinol) can improve the symptoms of schizophrenia. J Clin Psychopharmacol. 2009;29:255-258.
6. Meier MH, Caspi A, Ambler A, et al. Persistent cannabis users show neuropsychological decline from childhood to midlife. PNAS. 2012:E2657-E2664.
7. Grant I, Gonzalez R, Carey CL, et al. Non-acute (residual) neurocognitive effects of cannabis use: a meta-analytic study. J Int Neuropsychol Soc. 2003;9: 679-689.
8. Walther S, Halpern M. Cannabinoids and dementia: a review of clinical and preclinical data. Pharmaceuticals. 2010;3:2689-2708.
9. Amen DG, Darmal B, Raji CA, et al. Discriminative properties of hippocampal hypoperfusion in marijuana users compared to healthy controls: implications for marijuana administration in Alzheimer’s dementia. J Alzheimer Dis. 2017;56:261-273.
10. Gieringer D. Medical use of cannabis: experience in California. In: Grotenhermen F, Russo E, eds. Cannabis and Cannabinoids: Pharmacology, Toxicology, and Therapeutic Potential. New York: Haworth Integrative Healing Press; 2002:143-151.
11. Greer GR, Grob CS, Halberstadt AL. PTSD symptom reports of patients evaluated for the New Mexico Medical Cannabis Program. J Psychoactive Drugs. 2014;46:73-77.
12. Krumm BA. Cannabis for posttraumatic stress disorder: a neurobiological approach to treatment. Nurse Pract. 2016;41:50-54.
13. Abush H, Akirav I. Cannabinoids modulate hippocampal memory and plasticity. Hippocampus. 2010;20:1126-1138.
14. Akirav I. The role of cannabinoids in modulating emotional and non-emotional memory processes in the hippocampus. Front Behav Neurosci. 2011;5:34.
15. Neumeister A, Normandin MD, Pietrzak RH, et al. Elevated brain cannabinoid CB1 receptor availability in post-traumatic stress disorder: a positron emission tomography study. Mol Psychiatry. 2013;18: 1034-1040.
16. Bisaga A, Sullivan MA, Glass A, et al. The effects of dronabinol during detoxification and the initiation of treatment with extended release naltrexone. Drug Alcohol Depend. 2015;154:38-45.
17. Marcus A, Bachhuber MA, Saloner B, et al. Medical cannabis laws and opioid analgesic overdose mortality in the United States, 1999-2010. JAMA Int Med. 2014;174:1668-1673.
18. Shi Y. Medical marijuana policies and hospitalizations related to marijuana and opioid pain reliever. Drug Alcohol Depend. 2017;173:144-150.
19. Pisano VD, Putnam NP, Kramer HM, et al. The association of psychedelic use and opioid use disorders among illicit users in the United States. J Psychopharmacol. 2017. http://journals.sagepub.com/doi/abs/10.1177/0269881117691453. Accessed March 21, 2017.