Women who worry, cope poorly with stress and/or experience mood swings in middle age run a higher risk of developing Alzheimer disease later in life. This is the conclusion of a study carried out at the Sahlgrenska Academy, University of Gothenburg, that followed 800 women for nearly 40 years.
The study, which will be published in the scientific journal Neurology, started in 1968 when 800 women in Gothenburg took a personality test that measured, among other things, their levels of neuroticism and extroversion.
High Stress
The women in the study stated whether they had experienced long periods of high stress, and underwent memory tests. At the follow-up in 2006, nearly 40 years later, around one fifth of these women had developed dementia conditions.
"We could see that the women who developed Alzheimer disease had more often been identified in the personality test 40 years earlier as having neurotic tendencies. We found a clear statistical correlation for the women who had at the same time been subject to a long period of stress," says Lena Johansson.
Many Factors Involved
People who have a tendency to neuroticism are more readily worried, distressed, and experience mood swings. They often have difficulty in managing stress.
"We know that many factors influence the risk of developing dementia. Our personality may determine behavior, lifestyle and how we react to stress, and in this way affect the risk of developing Alzheimer disease," says Lena Johansson, scientist at the Sahlgrenska Academy, University of Gothenburg.
Having a personality with a tendency to extroversion or introversion did not increase the risk of developing Alzheimer disease, but shy women who at the same time became easily worried turned out to have the highest increase in risk in the study.
Stress is Harmful
Previous research into Alzheimer disease has focused on other factors such as education, family history and genetics. This is the first study that has followed participants from middle age to old age, and it shows the significance that personality may have in the risk of developing Alzheimer disease.
"Some studies have shown that long periods of stress can increase the risk of Alzheimer disease, and our main hypothesis is that it is the stress itself that is harmful. A person with neurotic tendencies is more sensitive to stress than other people," says Lena Johansson.