Stress Connected with Greater Chance of Memory Impairment

If you’re older and feeling stressed out you may be more likely to develop mild cognitive impairment, say researchers. MCI is often a precursor to full blown Alzheimer’s disease or other dementias. And you may be at greater risk if you’re also female, depressed and less educated.

Scientists at Albert Einstein College of Medicine and Montifiore Health System in New York City found that highly stressed participants were more than twice as likely to become impaired than those who were not. Because stress is treatable, the results suggest that detecting and treating stress in older people might help delay or even prevent the onset of Alzheimer’s.

Each year, approximately 470,000 people in the U.S. are diagnosed with Alzheimer’s disease. As of 2013, as many as 5 million Americans were living with the condition, according to the CDC. It often starts with symptoms of mild cognitive impairment—a pre-dementia condition that significantly increases the risk of developing Alzheimer’s in the following months or years.

This study looked at the connection between chronic stress and the most common type of mild cognitive impairment, known as “amnestic mild cognitive impairment,”  or aMCI. This is primarily characterized by memory loss.

“Our study provides strong evidence that perceived stress increases the likelihood that an older person will develop aMCI,” said Richard Lipton, M.D., senior author of the study, professor of neurology at Einstein and Montefiore, and Chair of Neurology at Einstein

Managing stress may modify risk
Perceived stress includes the daily hassles we all face, as well as the way we handle these events. The good news is that perceived stress is a modifiable risk factor for cognitive impairment, making it a potential target for treatment, said study authors.

For example, “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,” said study co-author Mindy Katz, M.P.H., senior associate in the Saul R. Korey Department of Neurology at Einstein.

How they did it
The researchers studied data collected from 507 people enrolled in the Einstein Aging Study (EAS), a community-based group of older adults. Since 1993, the EAS has systematically recruited adults 70 and over who live in Bronx County, N.Y. Participants undergo annual assessments that include clinical evaluations, a neuropsychological battery of tests, psychosocial measures, medical history, assessments of daily-living activities and reports (by participants and those close to them) of memory and other cognitive complaints.

Starting in 2005, the EAS began assessing stress using the Perceived Stress Scale (PSS). This widely used 14-item measure of psychological stress was designed to be sensitive to chronic stress (due to ongoing life circumstances, possible future events and other causes) perceived over the previous month. PSS scores range from 0 to 56, with higher scores indicating greater perceived stress.

The diagnosis of aMCI was based on standardized clinical criteria including the results of recall tests and reports of forgetfulness from the participants or from others. All 507 enrollees were free of aMCI or dementia at their first PSS assessment and later underwent at least one annual follow-up evaluation. They were followed for an average of 3.6 years.

Seventy-one of the 507 participants were diagnosed with aMCI during the study. The greater 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 percent.

Similar results were obtained when participants were divided into five groups (quintiles) based on their PSS scores. Participants in the highest-stress quintile (high stress) were nearly two and a half times more likely to develop aMCI than were people in the remaining four quintiles combined (low stress). When comparing the two groups, participants in the high-stress group were more likely to be female and have less education and higher levels of depression.

To confirm that stress was independently increasing risk for aMCI in this study, the researchers assessed whether depression—which increases the risk for stress as well as for cognitive impairment and Alzheimer’s disease—might have influenced the results. They found that depression did not significantly affect the relationship observed between stress and the onset of aMCI.

The findings were published online iAlzheimer Disease & Associated Disorders.

Maybe your New Year’s resolutions should include signing up for that meditation class?