January 13, 2015
High levels of anxiety may speed progression to Alzheimer’s disease in people with mild cognitive impairment, a form of memory or other cognitive loss that often precedes Alzheimer’s. Those are the findings of a Canadian study, one of the first to look at anxiety as an independent risk factor for dementia onset.
For the study, researchers from Baycrest Health Sciences’ Rotman Research Institute in Toronto followed 376 men and women, aged 55 to 91, over three years. All were known to have mild cognitive impairment, or MCI, at the start of the study.
Participants were given memory tests every six months to assess for progression to Alzheimer’s disease. They were also given tests to assess their levels of anxiety and depression. People in the study scored low on tests of depression but showed varying levels of anxiety.
The researchers found that those with symptoms of anxiety were more likely to progress to Alzheimer’s than those who had the lowest levels of anxiety. And the more anxious someone with MCI was, the more likely he or she would develop Alzheimer’s. Mild anxiety increased the likelihood of progression to Alzheimer’s by 33 percent; moderate anxiety increased the risk by 78 percent; and severe anxiety increased it by 135 percent.
“Our findings suggest that clinicians should routinely screen for anxiety in people who have memory problems, because anxiety signals that these people are at greater risk for developing Alzheimer’s,” said Dr. Linda Mah, the study leader and an assistant professor in the Department of Psychiatry at the University of Toronto.
It is unknown whether giving drugs or other treatments to ease anxiety may help stem the slide into Alzheimer’s. But, Dr. Mah said, “We think that at the very least, behavioral stress management programs could be recommended. In particular, there has been research on the use of mindfulness-based stress reduction in treating anxiety and other psychiatric symptoms in Alzheimer’s, and this is showing promise.”
Mindfulness therapies focus on paying attention to the present moment, through such techniques as meditation, paying attention to the breath, and observing the thoughts and emotions that fleet through the mind without making judgments.
Depression has also been cited as a risk factor for progression to Alzheimer’s. But the men and women in the current study scored low on depression assessment tests, suggesting that anxiety, independent of depression, is a risk factor for Alzheimer’s onset in those with MCI.
The research team also found that MCI patients who had reported symptoms of anxiety during the study had greater rates of shrinkage in parts of the brain critical for thinking and memory, the same brain regions affected by Alzheimer’s disease. Depression and chronic stress have also been linked to smaller brain volume and an increased risk of dementia.
It remains unknown how anxiety may damage the brain. But other studies have shown that even healthy people who experience high levels of stress in middle age are at higher risk of developing dementia in old age. Studies have also shown that stress can promote inflammation and raise blood pressure over the long term, both of which can damage the brain.
Many factors can contribute to Alzheimer’s, including age and genetics. Managing your long-term stress may be one way to help delay its onset.
Source: Baycrest Centre for Geriatric Care, Toronto, Canada. Linda Mah, Malcolm Binns, David Steffens: The American Journal of Geriatric Psychiatry. Published online ahead of print, Oct. 29, 2014.