Experiencing stressful events such as divorce, widowhood or losing a job may increase a woman's risk of developing dementia later in life, a new study has found.
The study of 800 women in Sweden found that experiencing such psychosocial stressors in midlife was linked with a 21 per cent increased risk of developing Alzheimer's disease, and a 15 per cent increased risk of developing any type of dementia, over nearly four decades.
Those who were exposed to psychosocial stressors were also at increased risk of experiencing prolonged periods of distress (or feelings of irritability, tension, nervousness, fear, anxiety or sleep disturbances).
However, such distress could not fully explain the link between psychosocial stressors and dementia, meaning that the association may, in part, be due to biological factors that change in response to experiencing stressors, researchers said.
The study analysed information from 800 Swedish women who periodically underwent testing between 1968 and 2005, 'LiveScience' reported.
At the study's start, participants were asked whether they had experienced any of 18 psychosocial stressors, including whether their spouse or close relative had a mental illness or abused alcohol, or whether they or their husband had lost a job.
Medical records and other information from psychiatric examinations were used to determine whether participants developed dementia over a 38-year period.
About a quarter of participants said they had experienced one psychosocial stressor, 23 per cent experienced two stressors, 30 per cent experienced three stressors and 16 percent experienced four stressors. The most common stressor was mental illness in a first-degree relative.
During the study period, about 20 per cent (153 people) developed dementia, 104 of whom developed Alzheimer's disease.
Psychological stress has been linked with increased production of inflammatory factors in the brain, and with an increased frequency of cardiovascular disease, and these, in turn, may be risk factors for dementia, the researchers said.
The study was published in the journal BMJ Open.
