A long-term study from Sweden did show that midlife stress, such as divorce, work pressures and health problems among parents or siblings, can increase the risk of Alzheimer’s disease (AD) later in life. In 1968, researchers from Gothenburg University began collecting data on more than 800 women who were in their late 30s to early 50s at the time. Over the years, the women underwent psychiatric exams and were asked about the stress in their lives and the signs of distress they experienced, including irritability, fear or sleep disturbances. The most common stressor mentioned was mental illness in a parent or sibling. By 2006, the researchers reported that about one in five of the women – a total of 153 – developed dementia at an average age of 79 and another 104 developed AD. Data from the study showed that it took 29 years for the dementia to develop.
The researchers found that a number of psychological stressors in midlife were associated with an increased risk of AD, and as well as an increased risk of developing any kind of dementia.
Other experts have suggested that the effects of chronic stress on certain hormones might reduce the efficiency of brain circuitry, putting some people at risk of dementia, including AD, later in life. One intriguing finding was that the number of stressors a woman listed seemed to affect her risk of Alzheimer’s whether or not she had felt stressed out by them at the time. Long-lasting stress was associated with greater risk.
AD appears be influenced by a combination of genetic, environmental, and other factors. A family history of the disease increases the risk slightly. In addition, women are more likely than men to develop it, and the same factors that raise the risk of heart disease, such as high blood pressure, high cholesterol, and diabetes, also increase the risk of AD. Research shows a link between lower education levels and higher risk of Alzheimer's disease, and some studies associate a history of traumatic head injury with increased Alzheimer's risk. Certain genetic mutations are known to cause early-onset Alzheimer’s and a form of the APOE gene increases the risk of late-onset disease.
The connection to midlife stress in women shown in the Swedish study will have to be examined in other studies with men and – because all the women were white – with other ethnicities.
Although it certainly has health benefits, we do not know whether stress reduction training can lower the risk of AD. In the meantime, here’s information about measures that research indicates may reduce your risk of Alzheimer’s disease.
Andrew Weil, M.D.