Anxious, jealous, moody or distressed middle aged women may be putting themselves at risk of developing Alzheimer's disease, according to a 38-year long study.
The claim, which appears in Neurology online, comes after scientists used personality and memory tests to track the health and welfare of 800 women who had an average age of 46. They found that 19pc of those women developed dementia in later life.
The tests also looked at their levels of neuroticism, whether they appeared to be shy and reserved, and if they were outgoing characters.
Neurology online is the medical journal of the American Academy of Neurology. Study author Lena Johannsson of the University of Gothenburg, Sweden, said: "Most Alzheimer's research has been devoted to factors such as education, heart and blood risk factors, head trauma and family history.
"Personality may influence the individual's risk for dementia through its effect on behaviour, lifestyle or reactions to stress."
Neuroticism involves being easily distressed and can be linked to worrying, jealousy or moodiness. People who are neurotic are more likely to express anger, guilt, envy, anxiety or depression. The study also looked at women who appeared to be shy and reserved plus those who seemed to be outgoing.
The women were asked if their work, health or family situation had left them feeling stressed for at least a month. Stress might be spotted by feeling irritable, tense, nervous, fearful, anxious and not being able to sleep properly.
Responses were ranked from zero, where the women never felt stressed, to five, where they had constantly experienced stress in the last five years. Women who chose responses from three and five were considered to have distress.
Those women with the highest scores on the tests for neuroticism had double the risk of developing dementia compared to those who scored lowest on the tests, according to the study.