Researchers in Sweden and the US have linked stress in middle-aged women to a higher risk of dementia later in life. The findings are published on 30 September in the journal BMJ Open.
The study followed 800 women born between 1914 and 1930 in Sweden, who were chosen for inclusion into the project in 1968. The women were examined at the start of the study, where they were asked about their exposure to psychosocial stressors and distress, and given a psychiatric assessment for signs of dementia. Psychosocial stressors included divorce, being widowed, work problems and illness in relatives. The women were then followed up at five intervals over the following 37 years.
At the start of the study, 25% of the women reported one stressor, 23% reported two, 20% reported three and 16% reported four or more. The number of psychosocial stressors present at the start of the study was associated with feelings of distress reported at each of the follow-up assessments.
Over the course of the follow-up period, 153 women developed dementia, of which 104 had Alzheimer’s. The researchers found that the number of psychosocial stressors measured at the start of the study was associated with a 15% higher risk of developing any type of dementia and a 21% higher risk of developing Alzheimer’s during the follow-up period.
The authors suggest there could be a number of factors responsible for the observed link, including a disruption in the hormonal signals in the brain resulting from exposure to stress.
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, the UK’s leading dementia research charity, said:
“These types of studies are important for looking at trends in people and highlighting areas for further investigation. This interesting study followed participants for almost four decades, which is hugely demanding but important for revealing how events in midlife may shape our health in older age. From this study, it is hard to know whether stress contributes directly to the development of dementia, whether it is purely an indicator of another underlying risk factor in this population of women, or whether the link is due to an entirely different factor.
“An important next step will be to investigate the potential reasons for the observed association between midlife stress and dementia risk, but lack of funds for dementia research threatens to hamper this progress. We know that the risk factors for dementia are complex and our age, genetics and environment may all play a role. Current evidence suggests the best ways to reduce the risk of dementia are to eat a balanced diet, take regular exercise, not smoke, and keep blood pressure and cholesterol in check. If you are feeling stressed or concerned about your health in general, we would recommend you talk this through with your GP.”