Alzheimer’s and Medical cannabis – A Brief Review of the Current Literature



     Alzheimer’s disease is generally considered an age-related neurological disease involving dementia, forgetfulness, and lack of proper brain function mostly in elderly patients. It can be progressive and severely debilitating both for the patients and their caregivers, and current treatment options and drugs are limited and not always effective.


     Controversial topics surround the use of medical cannabinoids for the treatment of disease, and the use of cannabis compounds in order to treat or reduce the symptoms associated with Alzheimer’s disease is a perfect example.  Studies are limited and have included such organizations as NIH, The Salk Institute, Psychology today, The Alzheimer’s Society, The Scripps Institute, among others. Israeli scientists at Tel Aviv University and other Israeli researchers are also using cannabis clinically in nursing homes and for the elderly, and these studies will soon be forthcoming with additional information. According to preliminary Israel clinical trials, “Adding medical cannabis oil to Alzheimer’s patients’ pharmacotherapy is a safe and promising treatment option.”



     On one hand, it seems that the use of cannabis and particularly THC can work to dull memory or affect the area of the brain (the hippocampus) which are involved in the disease process. Specifically, THC has been shown in one study to decrease the blood flow to the hippocampus, possibly with the result of cannabis promoting or increasing the susceptibility to the disease. This is currently a hypothesis and not clinically proven, but part of a published study by the Journal of Alzheimer’s Disease. It is perhaps true that the use of cannabis may not prevent the occurrence of Alzheimer’s, but perhaps play a role in mitigating symptoms, particularly aggression and lack of calm sleep for these patients.


     Some other studies show that the amyloid plaque buildup and neural inflammation associated with the disease is reduced using THC. Specifically, it was seen that marijuana reduced the Beta-Amyloid Plaque buildup in the brain, and this result also verified in lab studies in test tubes and non-human models. The production of the Beta-Amyloid plaque was reduced, and it was also noted that the neural inflammation seen in Alzheimer’s neural tissues was reduced as well. It is not known currently which of the different cannabinoids (i.e. THC, CBD, etc.) and their specific effect on human trials using cannabis, are beneficial in the treatment of the disease. Current thinking is that while it is possible cannabis can influence the disease process on a physiologic basis, it is likely that it can play a role in the symptomatology of these patients rather than offer a cure. By reducing the amyloid plaque and neural inflammation in the brains of these patients, clinical benefits may follow.



     One author notes that “There is some interesting evidence at laboratory level that certain components of cannabis may be able to target the underlying processes behind dementia, particularly Alzheimer's disease. However, at present, there is a lack of good-quality evidence and understanding as to how cannabis use affects a person's risk of dementia, or whether the drug can help to manage some of the symptoms of the condition. As cannabis use could negatively affect memory and thinking, particularly in heavy users, much more research needs to be done to tease apart any potential benefits and drawbacks.”


     While a study performed by Psychology Today claims “The evidence available from studies of humans and animal models of Alzheimer’s disease do indicate that long-term, low-dose daily exposure, during mid-life, to the complex blend of compounds found in the marijuana plant can effectively slow the brain processes underlying Alzheimer’s disease”.


     It is noteworthy that in considering the use of cannabis for Alzheimer’s, it is recommended that these patients are followed and monitored carefully by an experienced provider of medical cannabis to eliminate or reduce unwanted side effects that can occur with cannabinoids. As cannabis inevitably works its way into nursing homes and for elder care, more light will be shed on the use of cannabinoids in both the treatment of this disease and also its use to help with the symptoms of Alzheimer’s.