Office Hours: Murali Doraiswamy

Optimism about the rates of dementia
September 17, 2013

The director of the Neurocognitive Disorders Program in Psychiatry at the School of Medicine, Murali Doraiswamy is a leading Alzheimer’s expert and coauthor of The Alzheimer’s Action Plan. In a recent interview on PBS’ Newshour, Doraiswamy discussed new research that shows that rates of severe memory loss appear to be decreasing in consecutive generations.

On the hopeful signs of the studies:

Although the number of dementia cases is expected to continue to rise considerably due to greater longevity, our prior projections regarding the rate of increase might be slightly off base. The so-called silver tsunami that we’ve been warned about has been downgraded from grade five to grade four. So although we’re not yet out of the woods, these studies offer hope that successive generations or even slightly younger cohorts separated by as little as ten years may not have the same risk. The second thing I think that these studies are pointing out is that if the risk for Alzheimer’s is going down with successive generations, that is good news because it indicates that is likely to be due to environmental or lifestyle effects.

Les Todd.

On whether a decline in dementia includes Alzheimer’s cases:

Most of the time, but not always. It could very well be that much of the reduction that we’re seeing are reductions in a type of dementia called vascular dementia, which is accounted for largely by cardiovascular disease, by strokes, by high blood pressure, by high cholesterol. I suspect that that is the area where we have made the biggest gains, because we now have better ways to treat cardiovascular disease. I suspect Alzheimer’s also has gone down a little because vascular risks play a role there as well; and better education and diet, plus more exercise, also might lower the risk.

On warning signs:

Alzheimer’s plaque pathology can start building up in the brain decades before diagnosis. I was the lead author on a paper using a new PET scan to detect silent plaque buildup, and we showed that it might be possible to predict future memory loss. Forgetfulness can often start in a very, very mild form called subjective cognitive impairment that can resemble benign senior moments. Yet sensitive tests often are needed to detect such changes. Memory loss also can be caused by a variety of other conditions such as depression, stress, metabolic or vitamin deficiencies, or silent strokes. So it’s important to get an early evaluation.