Women who tend to be anxious, jealous, and moody in middle age could have a higher risk of developing Alzheimer's disease later in life.
The findings are the result of a nearly 40-year-long study published Oct. 1 in the online version of the online journal Neurology, the American Academy of Neurology reported.
"Most Alzheimer's research has been devoted to factors such as education, heart and blood risk factors, head trauma, family history and genetics," said study author Lena Johannsson of the University of Gothenburg in Sweden. "Personality may influence the individual's risk for dementia through its effect on behavior, lifestyle or reactions to stress."
To make their findings the researchers looked at 800 women with an average age of 46 and followed them for 38 years. The participants were given personality tests that assessed their neuroticism and extraversion or introversion, as well as their memory. Out of the pool of participants 19 percent had developed dementia at the conclusion of the study.
The women were also asked if they had experienced a time of their life lasting one month or longer that was characterized by high levels of stress in work, heath or family situations. Responses were ranked from zero to five, with zero representing never having experienced a period of stress and five signified constant stress. Women who chose answers between three and five were considered to have distress.
The researchers found women who scored highest on tests for neuroticism (involving "being easily distressed and personality traits such as worrying, jealousy or moodiness) had double the rate of dementia when compared with those who scored lowest on the test. The link was determined to be on long-standing stress. Women who are considered neurotic tend to experience side effects such as "anger, guilt, envy, anxiety or depression."
Being either introverted or extraverted did not appear to have an effect on dementia risk, but women who were both easily distressed and withdrawn had the highest rate of developing the condition.
