Although the medicinal properties of cannabis have been championed for quite some time(Russo), the investigation into its potential neuropsychiatric applications truly started in the 1990s following the discovery of the cannabinoid system in the brain(Iversen). This led to new ideas and possibilities that cannabis could probably have a great therapeutic role in regulating dopamine(“Dopamine (Rx)”; “Marijuana (Herb/Suppl)”), serotonin, and other neurotransmitters and offer a new means of treating a variety of diseases.
At the same time, efforts to relax marijuana(“Marijuana (Herb/Suppl)”) laws have successfully played out in several nations, including the United States, whereas of today, 36 states provide some access to cannabis(“State Medical Marijuana Laws”). These dual tracks — medical and political — have made cannabis an increasingly accepted(Carliner et al.) part of the normal culture.
With this development, a new dilemma has taken shape for the current clinicians. Medical cannabis has been made widely available to patients and has largely outpaced the clinical evidence, leaving it unclear how and for which indications it should be used. This relative unbalance and lack of scientific proof has painted an unreliable picture in the head of many physicians to use cannabis for medical purposes.
The Many Forms of Medical Cannabis
Cannabis is a genus of plants that includes marijuana (Cannabis sativa) and hemp. These plants contain over 100 compounds, including terpenes, flavonoids, and — most importantly for medicinal applications — cannabinoids.
The predominant cannabinoid(George T Griffing) in marijuana is the psychotropic delta-9-tetrahydrocannabinol (THC), which is largely responsible for many of the effects of feeling high. The next most abundant cannabinoid is cannabidiol(“Cannabidiol (Rx)”) (CBD), which is a non-psychotropic and doesn’t produce any alteration in perception. THC and CBD are the most extensively studied cannabinoids, together and in isolation. Evidence suggests that other cannabinoids and terpenoids may also hold medical promise(Russo and Marcu) and that various compounds included in cannabis can work together to produce a so-called entourage effect(Ferber et al.).
Patients have a wide array of options at a typical medical cannabis dispensary which can either be plant-based or synthetic and can differ considerably in terms of the ratios and amounts of THC and CBD they contain. Besides that, there are a lot of different ways these different products can be consumed (ie, via smoke, vapor, ingestion, topical administration, or oromucosal spray), all of which can have variable results. Further complicating matters is the varying level of oversight and regulatory hold each state and country has over the accuracy of the labeled products’ potency, cannabinoid content, and possible impurities.
Medically authorized, prescription cannabis products go through an official regulatory review process, and indications/contraindications have been established for them. To date, the US Food and Drug Administration (FDA) has approved(“Fda and Cannabis: Research and Drug Approval Process”) one cannabis-derived drug product — Epidiolex (purified CBD) — for the treatment of seizures associated with Lennox-Gastaut syndrome(Cherian) or Dravet syndrome in patients aged 2 years and older. The FDA has also approved three synthetic cannabis-related drug products ― Marinol, Syndros (or dronabinol(“Dronabinol (Rx)”), created from synthetic THC), and Cesamet (or nabilone(“Nabilone (Rx)”), a synthetic cannabinoid similar to THC) ― all of which are used for treatment-related nausea and anorexia associated with weight loss in AIDS patients.
“Cannabidiol (Rx).” https://reference.medscape.com/drug/epidiolex-cannabidiol-1000225.
“Dopamine (Rx).” https://reference.medscape.com/drug/intropin-dopamine-342435.
“Dronabinol (Rx).” https://reference.medscape.com/drug/marinol-syndros-dronabinol-342047.
“Fda and Cannabis: Research and Drug Approval Process.” https://www.fda.gov/news-events/public-health-focus/fda-and-cannabis-research-and-drug-approval-process.
“Marijuana (Herb/Suppl).” https://reference.medscape.com/drug/cannabis-ganja-marijuana-343687.
“Nabilone (Rx).” https://reference.medscape.com/drug/cesamet-nabilone-342048.
“State Medical Marijuana Laws.” https://www.ncsl.org/research/health/state-medical-marijuana-laws.aspx.
Carliner, H. et al. “Cannabis Use, Attitudes, and Legal Status in the U.S.: A Review.” Prev Med, vol. 104, 2017, pp. 13-23, doi:10.1016/j.ypmed.2017.07.008.
Cherian, Koshi A. “Lennox-Gastaut Syndrome.” https://emedicine.medscape.com/article/1176735-overview.
Ferber, S. G. et al. “The “Entourage Effect”: Terpenes Coupled with Cannabinoids for the Treatment of Mood Disorders and Anxiety Disorders.” Curr Neuropharmacol, vol. 18, no. 2, 2020, pp. 87-96, doi:10.2174/1570159×17666190903103923.
George T Griffing, Anne Thai. “Endocannabinoids.” https://emedicine.medscape.com/article/1361971-overview.
Iversen, L. “Cannabis and the Brain.” Brain, vol. 126, no. Pt 6, 2003, pp. 1252-1270, doi:10.1093/brain/awg143.
Russo, E. B. “History of Cannabis and Its Preparations in Saga, Science, and Sobriquet.” Chem Biodivers, vol. 4, no. 8, 2007, pp. 1614-1648, doi:10.1002/cbdv.200790144.
Russo, E. B. and J. Marcu. “Cannabis Pharmacology: The Usual Suspects and a Few Promising Leads.” Adv Pharmacol, vol. 80, 2017, pp. 67-134, doi:10.1016/bs.apha.2017.03.004.