Alzheimer’s Disease (AD) and Medical Cannabis

Definition

Alzheimer’s disease is a type of dementia, where an ongoing decline of brain function affects the sufferer’s memory, thinking skills, ability to care for themselves and other mental abilities. Mood swings and difficulty processing language are other symptoms. Age and genetics are the biggest risk factors in the development of Alzheimer’s, but depression, hypertension and head injuries are also contributing factors.

Potential Efficacy / Quality of Evidence (Low, Average, High) of Medical Marijuana for Alzheimer’s Disease

Average

Cannabinoids, Terpenes/Terpenoids, Strains and Ratios that May Help

THC could be particularly useful for removing beta-amyloid, the plaque-causing protein.

CBD may help reduce inflammation.

Terpenes such as limonene and pinene may help alleviate “brain fog” [1] to some extent.

CBC also has many neuroprotective properties.

CBD: THC 20:1; CBD:THC 1:1; THC may be helpful for dementia, although care must be taken with regards to dosage of THC.

Medical Cannabis Pros

Small doses of THC may help remove or prevent the clumping together of the plaque-causing Beta-Amyloid from brain cells [2].

Cannabidiol (CBD) may help prevent Beta-Amyloid-induced toxicity in PC12 cells and act as an anxiolytic.

Cannabinoids, in particular CBD, may help promote neurogenesis – the growth of new neural pathways.

Medical Cannabis Cons

THC, particularly in high doses, can cause problems and difficulties with memory, problem-solving and hand-eye coordination – not ideal for those with Alzheimer’s

Cannabinoids may alter the senses to some degree

More About the Condition

There is a lot of debate surrounding the use of cannabis for Alzheimer’s. Cannabinoids have the ability to promote neurogenesis [3], and some believe that they can be used to potentially delay the onset of Alzheimer’s. Alzheimer’s is also characterized by the formation of a plaque caused by the clumping together of the amino acid, amyloid beta. There is some evidence that a low dose of THC “directly interacts with Aβ peptide, thereby inhibiting aggregation.” [4] Nearly 30 million people worldwide suffer from Alzheimer’s disease.

However, most of the experiments on using cannabis for Alzheimer’s have been carried out on animals and extracted tissues, rather than living humans. THC’s effects on short-term memory may also be of concern for Alzheimer’s patients, and it could be the case that small amounts of THC may be helpful, whilst high amounts of THC are best avoided.

CBD may be of particular help by promoting neurogenesis, which can help prevent or even “resuscitate” dead or malfunctioning receptors, which can also help prevent anxiety. Small doses of THC may be helpful in removing preventing amyloid beta from clumping together. However, evidence is mostly in labs or anecdotal, and there are few definitive studies. Yet, medications based on synthetic versions of THC, such as marinol and dronabinol, are being tested for the treatment of agitation in those with Alzheimer’s [5]. However, whether synthetic versions of THC are as effective or as safe for Alzheimer’s disease or any number of other conditions is a matter of research

Quotes from Experts

“Several neurobiological effects of cannabinoids have been demonstrated which could be relevant in the treatment of dementia. The main function of the endogenous cannabinoid system (ECS) is thought to be the regulation of synaptic transmission (Baker 2003) and this process can be disordered in many neurological conditions including dementia.” Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6485913/ [6]

Case Studies – Patient Stories

https://www.wgbh.org/news/local-news/2019/04/09/can-marijuana-help-alzheimers-patients [7]

References

[1] https://www.alchimiaweb.com/blogen/pinene/

[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4543605/

[3] https://www.ncbi.nlm.nih.gov/pubmed/25024327

[4] https://www.nia.nih.gov/alzheimers/clinical-trials/dronabinol-treat-agitation-alzheimers-disease

[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6485913/

[6] https://www.wgbh.org/news/local-news/2019/04/09/can-marijuana-help-alzheimers-patients