A new 38-year study has linked personality traits, such as neuroticism combined with introversion, to an increased risk of Alzheimer’s disease in women. The research, which also found a link between high levels of stress and Alzheimer’s, was published on Wednesday 1 October in the journal Neurology online.
Researchers at the University of Gothenburg, in Sweden, followed 800 women who were enrolled in the Prospective Population Study of Women, who were aged between 38 and 54 when the research began. At the start of the study, in 1968, the women were assessed for their level of neuroticism (their tendency to experience emotions such as anxiety or moodiness), extraversion (how outgoing they were) and introversion (how shy and reserved they were). The researchers also measured the women’s distress levels by asking how often they experienced periods of stress. These assessments were repeated five more times over 38 years, with the last follow-up in 2005.
Over the course of the study, 153 women developed dementia, with 104 of these diagnosed with Alzheimer’s disease. The results showed that people who were introverts and also had high levels of neuroticism were more likely to have developed Alzheimer’s by the end of the study. The researchers also found that women with high levels of neuroticism, combined with high distress levels, were more likely to have developed Alzheimer’s – but in contrast, women who were highly neurotic but had low distress levels were no more likely to develop the disease than other people in the study.
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, the UK’s leading dementia research charity, said:
“Observational studies like this can be important for picking out health trends, but this type of research is not able to tell us about cause and effect. This long-term study adds to existing evidence linking stress to an increased risk of dementia, but more research is needed to understand the underlying reasons behind this link, as well as the impact of some of the personality traits highlighted here. There are many reasons for acting to reduce people’s stress levels, but controlled trials would be needed to know whether alleviating this type of stress could help prevent Alzheimer’s in later life.
“Understanding the factors that affect our risk of Alzheimer’s could provide new clues for preventing the disease, which is why investment in research is crucial. As the most common cause of dementia, Alzheimer’s affects around half a million people in the UK and with that number set to increase, we urgently need ways to prevent the disease.”