Stress increases risk for Alzheimer's precursor in older adults

Older people who feel stressed have a 30% greater risk for amnestic mild cognitive impairment (aMCI)—a type of memory loss that’s often a harbinger of Alzheimer’s disease. But stress can be reduced, so treating stress may help prevent the onset of aMCI and Alzheimer’s dementia, according to results from the Einstein Aging Study, published online December 15, 2015 in the journal Alzheimer Disease & Associated Disorders.

“Our study provides strong evidence that perceived stress increases the likelihood that an older person will develop aMCI,” said the study’s senior author Richard Lipton, MD, Professor in the Saul R. Korey Department of Neurology and the Edwin S. Lowe Chair of Neurology at Albert Einstein College of Medicine, in Bronx, NY. “Fortunately, perceived stress is a modifiable risk factor for cognitive impairment, making it a potential target for treatment.”

To examine whether perceived stress is a risk factor for cognitive decline and aMCI, Dr. Lipton and investigators administered the Perceived Stress Scale (PSS) to assess stress levels in 507 older adults (age 70 and older) who had no aMCI or dementia at baseline.

“Perceived stress reflects the daily hassles we all experience, as well as the way we appraise and cope with these events,” said first author Mindy Katz, MPH, senior associate in the Saul R. Korey Department of Neurology at Albert Einstein.

After an average 3.6 years of follow-up, 71 of the 507 participants were diagnosed with aMCI during the study. The higher the participants' stress level, the greater their risk for developing aMCI: for every 5-point increase in their PSS scores, their risk of developing aMCI increased by 30%.

When participants were divided into quintiles based on their PSS scores, those in the highest-stress quintile were nearly 2.5 times more likely to develop aMCI than those in the remaining four quintiles combined. Researchers also found that participants in the high-stress group were more likely to be female, have less education, and have higher levels of depression.

In addition, the researchers confirmed that stress independently increased risk for aMCI, and was not affected by depression or having an e4 allele of the Alzheimer's-related APOE gene.

This study’s finding that perceived stress can lead to mild cognitive impairment may in turn lead to intervention strategies that thwart the onset of aMCI and Alzheimer’s dementia, the researchers noted.

“Perceived stress can be altered by mindfulness-based stress reduction, cognitive-behavioral therapies, and stress-reducing drugs. These interventions may postpone or even prevent an individual's cognitive decline,” Ms. Katz said.