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.

Of those women,19 per cent developed dementia in later life. The tests also looked at their levels of euroticism, whether they appeared to be shy and reserved plus also if they were outgoing characters.

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, family history and genetics.

“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 women were asked if their work, health or family situation had left them feeling stressed for at least a month.

Personality may influence individual’s risk for dementia through its effect on behaviour, lifestyle or reactions to stress

Stress is spotted by feeling irritable, tense, nervous, fearful, anxious and not being able to sleep properly.

Responses were ranked from zero, where the women said they never felt stressed,to five, where they said they had constantly experienced stress in the last five years.

Women who chose responses from three to 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.

Being either withdrawn or outgoing did not appear to raise dementia risk alone, but women who were both had the highest risk of Alzheimer’s disease in the study.

It was found that 16 of the 63 women who were easily distressed and withdrawn developed Alzheimer’s disease.

This compared to eight out of the 64 people who were not easily distressed and were outgoing.