A growing number of countries are continuing to liberalise access to medical cannabis for the treatment of a wide range of conditions as well as for symptom relief. While legal access may remain limited, research and public interest is consistently on the rise, potentially opening the doors to further use of medical cannabis treatment in the future. One area, in particular, which has gained substantial interest in recent years is the potential of medical cannabis in dementia treatment.
What is dementia?
In contrast to being a specific disease, dementia refers to the impairment in a person’s ability to remember, think, or make decisions, to the extent that it interferes with their everyday life. For example, Alzheimer’s disease is the most common form of dementia accounting for around two-thirds of cases, with other types including vascular dementia, mixed dementia, Lewy body dementia, frontotemporal dementia, and young-onset dementia.
Dementia is most common in older people, but it is not a normal part of ageing. While we can expect to start misplacing keys more frequently or forgetting the names of acquaintances as we get older, dementia symptoms eventually become much more serious as the specific disease progresses. This can be increasingly difficult for those living with dementia and those close to them to deal with.
According to the World Health Organisation 2022 report on dementia, there are an estimated 55 million people living with dementia worldwide – and this figure is on the rise. In fact, figures are projected to reach 152 million by 2050. The rising prevalence of dementia coupled with the significant suffering experienced by those diagnosed and their loved ones makes finding effective and useful therapies extremely important.
Current treatment options
Treatment options for dementia depend largely on the underlying cause in each patient. For example, some types of dementia, like Alzheimer’s disease, are neurodegenerative and have no cure; however, about 10% of dementia cases are linked to strokes or other issues with blood flow to the brain (vascular dementia). In some cases, dementia can even be linked to medications, increased pressure in the brain, vitamin deficiency, or thyroid hormone imbalance.
Current evidence suggests that regular exercise, eating healthily, and maintaining social contact may help to decrease the chance of dementia developing or the rate at which it progresses. Other treatments such as therapy and cognitive rehabilitation are also often an important part of treatment; however, medications may be prescribed to temporarily reduce symptoms and associated challenging behaviour.
While these medications may be crucial for helping many patients with dementia and their families to cope, they may also be associated with unwanted side effects such as loss of appetite and problems sleeping.
Medical cannabis and dementia
Neuropsychiatric symptoms are common to all types of dementia and are among the main targets for treatment. Such symptoms may manifest as agitation, aggression, apathy, sleep disorders, depression, anxiety, psychosis, and eating disorders. Interestingly, medical cannabis has been implicated as a potentially useful option in many of these symptoms.
To date, few studies have focused specifically on the potential of medical cannabis treatment in patients with dementia. However, limited evidence does suggest that cannabis and its derivatives may be useful for a number of dementia symptoms.
What is the evidence?
A 2019 systematic review, which assessed 12 studies (including 6 randomised controlled trials) found that dronabinol and THC were “associated with significant improvements in a range of neuropsychiatric scores.” However, the researchers note that while observational studies yielded promising results, the efficacy of cannabinoids was not proven in a robust randomised controlled trial.
Another observational study conducted on dementia patients in a specialised nursing home in Geneva demonstrated similar results. The researchers found that treatment with a THC/CBD extract was associated with a 40% reduction in behaviour problems. Half of patients also reduced or stopped other psychotropic medications, including opioids, and nurses reported that daily care was easier due to improved contact with patients and improvements in behaviour. Furthermore, medical cannabis was found to be well-tolerated with no patients stopping treatment.
There is also a growing body of evidence for the potential of cannabis-based medicines for many common symptoms of dementia, including sleep problems, anxiety, and loss of appetite. For example, medical cannabis can already be considered in some countries in cases of wasting and appetite loss associated with conditions such as HIV/AIDS and cancer.
An increasing number of studies are also focusing on cannabis-based medicines for sleep disorders, including insomnia, and anxiety. For example, one study found that 71% of participants with insomnia or another sleep disorder experienced improvements in their sleep after initiating medical cannabis treatment.
While much more high-quality evidence is required before a clear conclusion can be drawn on the potential role of cannabis in dementia treatment, the early findings are promising. In the coming years, it is likely that research will continue to build on these findings as the need for more effective treatments becomes increasingly urgent.