By Fredrick Kunkle October 1 at 4:54 PM
Here’s something to worry about: a recent study suggests that middle-aged women whose personalities tend toward the neurotic run a higher risk of developing Alzheimer’s disease later in life.
The study by researchers at the University of Gothenburg in Sweden followed a group of women in their 40s, whose disposition made them prone to anxiety, moodiness and psychological distress, to see how many developed dementia over the next 38 years.
In line with other research, the study suggested that women who were the most easily upset by stress – as determined by a commonly used personality test – were two times more likely to develop Alzheimer’s disease than women who were least prone to neuroticism.
In other words, personality really is, in some ways, destiny.
“Most Alzheimer’s research has been devoted to factors such as education, heart and blood risk factors, head trauma, family history and genetics,” study author Lena Johansson said in a written statement. “Personality may influence the individual’s risk for dementia through its effect on behavior, lifestyle or reactions to stress.”
The researchers cautioned that the results cannot be extrapolated to men because they were not included in the study and that further work is needed to determine possible causes for the link.
The study, which appeared Wednesday in the American Academy of Neurology’s journal, Neurology, examined 800 women whose average age in 1968 was 46 years to see whether neuroticism – which involves being easily distressed and subject to excessive worry, jealousy or moodiness – might have a bearing on the risk of dementia.
Their personalities were assessed using the Eysenck Personality Inventory, a commonly administered test to rate a person’s disposition, emotional stability and relative tendency toward introversion, which is associated with shyness or reserve, or extraversion, which is used to describe more outgoing people.
The women also were asked to rate their levels of stress based on self-reported evaluations conducted in 1968, 1974, 1980, 2000 and 2005. (The question they were asked was, “Have you experienced any period of stress [1 month or longer] in relation to circumstances in everyday life, such as work, health, or family situation?”) Stress was defined as anything stirring feelings of anxiety, irritability, tension, fear, nervousness or sleep disturbances.
Diagnoses of dementia were based on neuropsychiatric examinations, interviews with people close to the participants and others, and medical records. The mean age for onset of dementia was 78 years.
Of the 800 who began the study, 153 women developed dementia, including 104 diagnosed with Alzheimer’s disease, which is the most common cause of dementia.
Those women who scored highest on the scale of neuroticism had double the risk of developing dementia compared with those who scored the lowest – although the link also depended on whether the subjects also felt subjected to long-term stress.
Being extroverted or introverted on its own did not appear to heighten the risk of dementia, although the study found that women who were easily distressed and also tended to be introverted were at the highest risk of Alzheimer’s.
The researchers said possible explanations for the link could be that a person’s personality affects behavior and lifestyle, and that people who are rated low on neuroticism engage in practices that promote healthier metabolic, cardiovascular and inflammatory responses. It’s also possible that the combination of sustained stress and neuroticism has been shown to cause functional and structural changes in parts of the brain that control emotion, cognition and memory and are most affected by dementia.