Stress and Alzheimer's Disease

Can Stressful Events in Middle Age Cause Dementia?

We know that stress can interfere with your quality of life and your relationships, hurt your health and reduce your overall longevity.  Chronically-elevated levels of the stress hormone cortisol leave you vulnerable to heart disease, diabetes, and more. But can ongoing stress in middle-age actually lead to dementia in later life?

The answer is "yes," according to a 2013 Swedish paper published in BMJ Open, an online peer-reviewed journal.

  Part of the Prospective Population Study of Women in Gothenburg, Sweden, the research tracked 800 older women over almost 40 years.  The longitudinal study began in 1968, when the subjects were all between their late 30s and early 50s.

Stressful events in midlife:  When the study began in 1968, 18 specific circumstances or "stressors" were identified which may have caused the subjects emotional or physical hardship.  These included divorce, loss of a spouse, mental illness or substance abuse in a spouse or family member, workplace difficulties, requiring government social assistance, or having only a limited social network.

Measuring distress:  Assessing the women via questionnaires and psychiatric evaluations in their daily lives over a 37-year period, the researchers asked whether the subjects had experienced distress for a period of one month or more in their everyday life.  Distress was defined in terms of feelings like nervousness, anxiety, fear, irritability, or disturbances in their sleep on a scale of 0 (never) to 5 (constant distress over the last five years).

  If distress ranked between a 3 and a 5 on this scale, the researchers included it in their study.

At the beginning of the research, the proportion of women reporting one or more stressors broke down in the following way:

  • 25% reported 1 stressor
  • 23% reported 2 stressors
  • 20% reported 3 stressors
  • 16% reported 4 or more stressors

    What the researchers found: Over the study period, 19% of the subjects developed dementia, most often Alzheimer's disease (the most common form).  After adjusting the results for potential confounding effects - that is, factors which may influence the results - such as education level, socioeconomic status, and psychiatric family history, as well as other physiological risk factors such as heart disease, diabetes and smoking, the women who had a higher number of stressors when the study began in 1968 were about 20% more likely to develop Alzheimer's disease.  The risk increased as the number of stressors grew.

    These results do not prove that experiencing stressful events like divorce or job loss in your 40s will cause dementia in older age, they simply show that in this investigation, mid-life stress was associated with a greater incidence of Alzheimer's later on.  The researchers point to previous research showing traumatic events such as the loss of a spouse can increase the risk for dementia, and suggest that physical changes in the body's immune, hormonal and cardiovascular systems might be to blame.


    US veterans who've experienced post-traumatic stress disorder have been found to be twice as likely to develop dementia than those without the disorder, as reported in a 2010 study on 181,093 veterans 55 years or older.

    The exact causes of Alzheimer's disease are not yet known, though age, family history and genetics are all risk factors.  In addition, regular physical exercise and brain-healthy diet seem to help prevent the disease.

    If stress is eventually established as a risk factor as well, the authors of this Swedish study write that managing stress more effectively in middle age could also be a valuable intervention to help adults avoid cognitive decline.  


    Kristine Yaffe, Eric Vittinghoff, Karla Lindquist, et al. "Post-Traumatic Stress Disorder and Risk of Dementia among U.S. Veterans."  Arch Gen Psychiatry. 2010 June; 67(6): 608–613.

    Johansson L, Guo X, Hallstrom T, Maria C Norton, Margda Waern, Svante Ostling, Calle Bengstsson, Ingmar Skoogl. "Common Psychological Stressors in Middle-Aged Women Related to Longstanding Distress and Increased Risk of Alzheimer's Disease: A 38-Year Longitudinal Population Study." BMJ Open 2013;3:e003142.

    What is Alzheimer's? Alzheimer's Association Public Information Sheet. Accessed October 15, 2013.

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