Stress at 40, Dementia at 60?

Vermeer at New research just published that falls into the “I sure hope this isn’t true” category: midlife psychological stress may have a relationship to the development of dementia later in life. As the number of people with dementia continues to increase dramatically with global aging of the human population, the exact causes of this frightening disease are poorly understood. Now comes this 35-year-long study, whose results have been published in the peer-reviewed journal Brain, that adds new fuel to the speculation that psychological (i.e. cognitive and emotional) stress may have something to do with the development of dementia…at least in women.

Swedish and American scientists at Gothenburg University and at the SUNY Downstate Medical Centre in Brooklyn analyzed the relationship between psychological stress in midlife and the development of dementia in late-life. A group of 1,462 women, whose age ranges between 38 and 60, were examined in 1968–69 and re-examined in 1974–75, 1980–81, 1992–93 and 2000–03. During the 35-year follow-up, 161 cases of dementia were diagnosed among the women in this study—105 of the Alzheimer’s type, 40 vascular dementia and 16 other dementias.

The results indicate that the incidence of dementia was higher among women who had reported frequent or constant psychological stress in 1968, in 1974 and in 1980. More specifically, women who reported frequent or constant stress in 1968 and 1974 had more cases of Alzheimer’s disease. Moreover, women who reported psychological stress at one, two or three examinations were found to have a sequentially higher risk of developing dementia in later years.

The researchers conclude that this study demonstrates a clear association between psychological stress in middle-aged women and the development of dementia, especially Alzheimer’s disease. While they caution that additional studies are needed to confirm these findings and to study potential neurobiological mechanisms of these associations, nonetheless the length of the study and the rigorous collection of data from multiple sources lend credibility to the results.