Week 14: Future Prospects in Dementia Research

Written by Dr. Nathan Herrmann, MD FRCPC

Lewar Chair in Geriatric Psychiatry
Professor, Faculty of Medicine, University of Toronto
Head, Division of Geriatric Psychiatry, Sunnybrook Health Sciences Centre

As mentioned in a previous posting, at the moment, there are only 4 drugs approved in Canada for the treatment of the symptoms of Alzheimer’s disease. These 4 drugs provide modest benefits at best, and do not change the inevitable progression of the illness. While there has been decades of intense research, Alzheimer’s disease still cannot be prevented, its inevitable progression cannot be appreciably slowed or halted, and even its symptoms cannot be dramatically improved. Research continues however, with scientists generally targeting the 3 major pathological components of the illness which are amyloid, tau, and inflammation.

One of the more disappointing failures in the last several years has been the antibody treatments, including the recent results with solanezumab. This did not slow memory and cognitive decline in a large, lengthy study of people with mild Alzheimer’s disease. This type of treatment, aimed at removing amyloid, has also failed in many other studies with similar agents. There are still a couple of other similar antibody therapies and drugs aimed at reducing amyloid that are going into trials this coming year. These include trials of individuals who do not have Alzheimer’s disease diagnosed, but are at high risk for developing the disease based on family history and/or genetic profile.

Another disappointment this past year was the failure of a drug aimed at tau. Given that the majority of treatments that have been researched to date have focused on amyloid, this much newer focus is potentially exciting, and several antibody treatments for tau are in early development. Finally, a number of drug treatments which effect insulin and blood sugar are being examined given an intriguing relationship between insulin, blood sugar and the development of Alzheimer’s Disease.

Dietary supplements have also received attention recently. Medium chain fatty acids or triglycerides have been studied and are currently being examined in several trials. Coconut oil is an excellent source of these fatty acids, and while likely completely safe, its use cannot be widely recommended at present given the lack of definitive research.

Non-drug therapies are also being studied intensively. Unfortunately, while researchers have been studying treatments like exercise and cognitively stimulating activities like computer games, these interventions have not yet demonstrated that they can effectively prevent or delay the onset of Alzheimer’s disease or other dementias. Direct brain stimulation using electricity, magnetism, and even special lights, is being studied as well.

We are involved in a particularly exciting study aimed at preventing Alzheimer’s disease. This study of over 300 people who are at high risk for developing Alzheimer’s disease will follow people for up to 5 years or longer. We have chosen 2 groups of older individuals who are at high risk of developing dementia – those with mild cognitive impairment (but no dementia), and those who have experienced a clinical depression in the past. These individuals attend an 8 week, daily classroom course of “cognitive remediation” with specialized computer games, as well as receive a safe neurostimulation treatment called transcranial direct current stimulation. While we are about halfway through the study, we are continuing to actively recruit subjects for the trial. If you, or someone you know are interested in this study, please call us at 416-583-1350. Perhaps together we will find a cure for this terrible illness!