By Andrew M. Seaman
NEW YORK (Reuters Health) - Anxious, jealous, moody, distressed women are more likely to develop Alzheimer’s disease later in life than their calmer and less stressed-out counterparts, suggests a new study.
Women who scored highest on a test for neuroticism in mid-life were twice as likely to go on to develop Alzheimer’s disease, compared to women with the lowest neuroticism scores, researchers found.
“All common disorders like Alzheimer’s disease or cardiovascular disease are multi-factorial and this is one of the factors,” said Dr. Ingmar Skoog, the study’s senior author from the University of Gothenburg in Sweden.
The findings may suggest that people with certain negative personality traits could use behavioral therapies to tackle those and thereby also reduce their risk of developing Alzheimer’s disease later in life, researchers said.
“I think for the average person, it’s not that ‘I have neuroticism and I’m going to get Alzheimer’s disease,’” said Dr. James Galvin. “It’s, ‘I have these traits and doing something about these traits can do something about my risk.’”
Galvin, who was not involved in the new study, is a professor of neurology, psychiatry, and population health at NYU Langone Medical Center in New York City.
About 5 million Americans are living Alzheimer’s disease, according to the U.S. Centers for Disease Control and Prevention. It is the most common form of dementia.
While the exact cause of Alzheimer’s disease is unknown, researchers have identified a variety of risk factors for developing the condition, including high blood pressure and high cholesterol.
Skoog and his colleagues write in the journal Neurology that personality may also influence Alzheimer’s risk through its effects on behavior and lifestyle. Neuroticism, specifically, has already been linked to dementia and Alzheimer’s disease, they add.
For the new study, the researchers tracked 800 middle-aged women for 38 years starting in 1968 when they were between 38 and 54 years old.
About 19 percent - or 153 - of the women ended up with dementia by the end of the study. Of those, 104 were diagnosed with Alzheimer’s disease.
Women who scored the highest on a test for neuroticism at the start of the study were twice as likely to be diagnosed with Alzheimer’s disease, compared to those who scored lowest on that test.
After accounting for stresses the women experienced throughout their lives, the connection between neuroticism and dementia weakened. The researchers have previously reported that stress during middle-age may increase the risk of dementia, including Alzheimer’s disease.
In addition to neuroticism, the researchers also looked at how extroverted the women were and found that being extroverted was tied to less stress. Women who were the most neurotic and least extroverted were most likely to develop Alzheimer’s disease.
While the study only included women, Skoog and Galvin both said they don’t think the results would be different among men.
The results do not prove that being neurotic causes Alzheimer’s disease. There can be a few explanations, including, for example, that neuroticism may promote unhealthy lifestyles or behaviors that increase other risk factors for Alzheimer’s disease.
Still, Skoog said, addressing neuroticism with treatments like cognitive behavioral therapy may lower stress throughout a person’s life and ultimately reduce the risk of Alzheimer’s disease.
“If we can identify things that are addressable in midlife, then we may be able to subsequently reduce the risk of bad outcomes in later life,” Galvin said.
Healthy diet and exercise in midlife have also been thought to reduce the likelihood of developing Alzheimer’s disease later on, Skoog said.
“Now you have this thing, if you have a high neuroticism scores, you can try to do something about it,” he said. “I think that’s the take home message for this.”
SOURCE: bit.ly/1xCRlWx Neurology, online October 1, 2014.