Alzheimer’s disease is a chronic neurodegenerative disorder that affects millions of people worldwide. Symptoms include memory loss, problems with language, disorientation, mood swings, and difficulty managing activities of daily living. About 70% of cases are thought to be genetic in cause. Researchers have found that the brains of people with Alzheimer’s disease have abnormal deposits called myeloid plaques and neurofibrillary tangles. These plaques and tangles disrupt the brain cells’ ability to function properly and lead to cell death, which subsequently leads to the terrible symptoms of Alzheimer’s. It has also been reported that this condition may result from years of inflammation of the nerves in the brain.
Cannabinoids are well known to be potent anti-inflammatory compounds and have been shown in multiple studies to decrease neuroinflammation. Research investigating the use of cannabinoids for Alzheimer’s are summarized:
One of the main concerns involved in deciding to treat patients with Alzheimer’s disease with cannabis is that THC itself can cause memory loss, disorientation, agitation and anxiety in some people. It is therefore recommended that if THC is to be used, it should be used in very small doses and titrated up very slowly. Chemovars rich in the terpenoid myrcene are sedating and can be helpful for agitated Alzheimer’s patients. Sublingual tinctures that are tested for potency and that contain small amounts of THC allow for controlled dosing and prevention of unwanted side effects. However, it appears from recent research that combination treatment with CBD plus THC had better results in mice than either compound alone.
Since it has been shown that CBD can protect from memory loss8,9,10 and can counteract the anxiety and paranoia that can occur in some who take THC,11 it would be helpful to include CBD in any cannabis treatment for Alzheimer’s. Unfortunately there have been no human trials proving effectiveness of cannabis in preventing the onset or delaying the progression of Alzheimer’s, but research with animals has shown some promising results. The terpenoid pinene is desirable in these patients as it has been shown to enhance memory.12
Eubanks, Lisa M., et al. “A molecular link between the active component of marijuana and Alzheimer's disease pathology.” Molecular pharmaceutics 3.6 (2006): 773-777.
Caoa, Chuanhai, et al. “The potential therapeutic effects of THC on Alzheimer’s disease.” neurodegeneration 24 (2014): 25.
Benito, Cristina, et al. “The endocannabinoid system and Alzheimer’s disease.” Molecular neurobiology 36.1 (2007): 75-81.
Aso, Ester, and Isidre Ferrer. “Cannabinoids for treatment of Alzheimer’s disease: moving toward the clinic.” Frontiers in pharmacology 5 (2014).
Eubanks, pp. 773-777.
Iuvone, Teresa, et al. “Neuroprotective effect of cannabidiol, a non‐psychoactive component from Cannabis sativa, on β‐amyloid‐induced toxicity in PC12 cells.” Journal of neurochemistry 89.1 (2004): 134-141.
Aso, Ester, et al. “Cannabis-Based Medicine Reduces Multiple Pathological Processes in AβPP/PS1 Mice.” Journal of Alzheimer's disease: JAD 43.3 (2015): 977-991.
Englund, Amir, et al. “Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment.” Journal of Psychopharmacology 27.1 (2013): 19-27.
Fagherazzi, Elen V., et al. “Memory-rescuing effects of cannabidiol in an animal model of cognitive impairment relevant to neurodegenerative disorders.” Psychopharmacology 219.4 (2012): 1133-1140.
Morgan, Celia JA, et al. “Impact of cannabidiol on the acute memory and psychotomimetic effects of smoked cannabis: naturalistic study.” The British Journal of Psychiatry 197.4 (2010): 285-290.
Englund, pp. 19-27.
Russo, Ethan B. "Taming THC: potential cannabis synergy and phytocannabinoid‐terpenoid entourage effects." British journal of pharmacology 163.7 (2011): 1344-1364.