June 20, 2007
People who are easily distressed or flustered and who are prone to emotions such as anxiety and depression are more likely to develop memory problems as they age than more easygoing people, according to a new study. The findings were published in Neurology, the scientific journal of the American Academy of Neurology.
In the study, men and women who most often experience negative emotions such as depression and anxiety were 40 percent more likely to develop mild cognitive impairment than those who were least prone to negative emotions. Mild cognitive impairment (MCI), marked by memory or other cognitive loss, sometimes progresses to Alzheimer's disease. People with the condition have mild cognitive problems but no significant disability. For example, they can continue working. However, MCI differs from a milder, age-related decline in memory that is believed to be a normal part of ageing. MCI affects an estimated 15 percent of the senior population.
Researchers analyzed the results from two larger studies, the Religious Orders Study and the Memory and Aging Project. The studies involved 1,256 people who, at the start of the study, had intact memories. During the 12 years of follow-up, 482 people developed mild cognitive impairment. Participants were questioned about their likelihood of becoming distressed or anxious by rating their level of agreement with statements such as "I am not a worrier," "I often feel tense and jittery," and "I often get angry at the way people treat me."
"People differ in how they tend to experience and deal with negative emotions and psychological distress, and the way people respond tends to stay the same throughout their adult lives," said study author Robert S. Wilson, PhD, of Rush University Medical Center in Chicago. "These findings suggest that, over a lifetime, chronic experience of stress affects the area of the brain that governs stress response. Unfortunately, that part of the brain also regulates memory."
Hazards of Stress
Studies suggest that stress may play an important role in the progression of Alzheimer's, a disease that causes damage to parts of the brain essential for thinking and memory. Last year, for example, scientists at the University of California at Irvine found that mice injected with a drug that mimics stress in people had high levels of beta-amyloid, a toxic protein that builds up in the brains of those with Alzheimer's disease. The findings suggest that managing stress may be an important part of an Alzheimer's care plan. [See the article, "Stress May Hasten Progression of Alzheimer's Disease."]
Studies have likewise shown that, even in healthy people, the stress of caring for a loved one with Alzheimer's can also damage health. [See the article, "Caregiving May Be Hazardous to Your Health."] Other research has shown that counseling and care from a team of experienced health-care providers may be key to managing stress, both in those with Alzheimer's and those who care for them. [See the article, "Counseling Offers Lasting Benefits for Alzheimer's Caregivers."]
Stress is a natural response as memory fades and everyday tasks become more difficult in those with mild cognitive impairment or during the early stages of Alzheimer's disease. Fading memory also increases the likelihood of physical ailments and disability.
Wilson, the author of the current study, said several factors lead researchers to believe that being prone to stress is a risk factor for memory problems and not an early sign of disease. For example, while the level of distress does not appear to increase in old age, the changes in the brain related to memory problems and Alzheimer's disease do increase with age.
We at the Fisher Center strongly agree with the idea that stress reduction is critically important in caring for the person with Alzheimer's disease. Keeping stress levels down is also key for caregivers. To learn more, visit www.ALZinfo.org.
The American Academy of Neurology.
R.S. Wilson, PhD; J.A. Schneider, MD; P.A. Boyle, PhD, et al: "Chronic Distress and Incidence of Mild Cognitive Impairment." Neurology, Volume 68, June 12, 2007, pages 2085-2092.