Even more common is Alzheimer disease, the number one cause of dementia, and a tremendous public health burden. Current drugs aim to replace acetylcholine, the memory molecule of the brain that becomes deficient, but none halt the degenerative process. Available research indicates that both THC and CBD can interfere with the buildup of beta-amyloid and neurofibrillary tangles that are part of the pathological processes in Alzheimer disease. Additionally, THC and cannabis calm the agitation of the disorder and allow better sleep patterns. Further research, some currently underway, may help answer whether cannabis-based drugs can actually produce neuroprotective effects that slow or even arrest the disease process.
Traumatic brain injury (TBI) is an important cause of morbidity and mortality from accidents, warfare, and even contact sports. The most common form is concussion, which produces a constellation of problems including headache, fatigue, nausea, dizziness, and cognitive impairment. Repetitive head trauma has been linked to a degenerative condition now called chronic traumatic encephalopathy (CTE) especially associated with American football, in which years later people develop degenerative dementia, personality change, violent behavior, and even hallucinations. The neuroprotective effects of cannabis are well established in the literature, and there is a tremendous amount of anecdotal literature that cannabis benefits symptoms in both syndromes. Formal clinical trials are necessary.
Are there any other neurological disorders that cannabis might be able to help treat?
Russo: Cannabis-based medicines are well studied in treating symptoms of multiple sclerosis (MS), whether it be spasticity, for which Sativex is approved in 30 countries, but also for associated pain, sleep disturbance, and lower urinary tract symptoms.
Cannabis has benefitted patients with Tourette syndrome in several studies and has a strong theoretical basis in treating amyotrophic lateral sclerosis (ALS). A clinical trial in the latter is underway in Australia.
Numerous other neurological syndromes are currently being treated with cannabis and deserve formal investigation.
In another recent article (2), you addressed the practical considerations in administering and dosing medical cannabis. One of the biggest challenges is the lack of education for physicians in this area, how do you think that problem can be solved? Is there a resource that doctors can use to learn more about various cannabis treatment options and recommended dosing?
Russo: My colleague Caroline MacCallum and I recognized that while certain doctors in the world are experienced in advising patients on cannabis formulations and their use, and such information has been available in books, until 2018, there was no peer-reviewed scientific journal article that directly addressed the issue. We felt that this was a serious deficiency producing a knowledge gap that impeded progress in supplying patients and their doctors with the foundations necessary to inform proper approaches to cannabis therapeutics. Our article (2) is available on open source and we hope that it will be widely shared. Additional excellent books are available and are listed below (3–5).
What are some of the other major considerations for dosing?
Russo: THC is the limiting factor in cannabis dosing. In general, 2.5 mg of THC is a threshold dose for people who are not tolerant to its effects, 5 mg is a moderate dose, and 10 mg at once is too much for most patients not accustomed to the effects. I recommend that the total daily dose of THC not exceed 20–30 mg after a slow titration (adjustment of dose upwards), preferably in conjunction with a lot more CBD and terpenoids that buffer the effects of THC. The best adage is: “Start low and go slow!”
What cannabis research projects are you currently working on?
Russo: ICCI provides aid to the cannabis industry in all facets, whether it be identification of novel chemovars (chemical varieties), planning clinical trials, developing cannabis standards for cultivation, extraction and production, investigating new distribution networks, and everything hemp related, whether it be for nutrition or industrial applications. We are also directly involved in research on wound healing, treatment of Alzheimer disease, and cancer, among others. We have in-house projects that will investigate new diagnostic tests and development of nonprescription cannabis-based products for different common conditions.
What do you think is the biggest problem facing the medical cannabis industry and do you have any plans to solve it?
Russo: The biggest problem facing the cannabis industry is ignorance amongst physicians and the politicians that make the rules for the rest of us. I have been battling this every day for the last 23 years! All that I can do is to keep trying.
- E. Russo, "Cannabis therapeutics and the future of neurology." Front. Integr. Neurosci. 12, 51, 10.3389/fnint.2018.00051 (2018). https://www.frontiersin.org/articles/10.3389/fnint.2018.00051/full.
- C.A. MacCallum and E.B. Russo, "Practical considerations in medical cannabis administration and dosing." Eur. J. Intern. Med. 49, 12–18 https://doi.org/10.1016/j.ejim.2018.01.004 (2018).
- M. Backes, Cannabis Pharmacy: The Practical Guide to Medical Marijuana (Black Dog and Leventhal Publishers, New York, New York, 2017).
- B. Goldstein, Cannabis Revealed: How the World's Most Misunderstood Plant Is Healing Everything from Chronic Pain to Epilepsy (Bonni S. Goldstein MD Incorporated, Los Angeles, California, 2016).
- N. Whiteley, Chronic Relief: A Guide to Cannabis for the Terminally and Chronically Ill (Alivio, LLC, Austin, Texas, 2016).