The study by Lena Johansson and colleagues recently published in [i]Brain[/i]  was based on data from a population cohort, as a part of the Prospective Population Study of Women in Gothenburg, Sweden. The objective was to analyze the relationship between psychological stress and the development of dementia in late life. The study followed 1415 women, aged 38–60 years, during a period of 35 years. The women were examined between 1968 and 2000 at three times, in which a standardized single question about psychological stress was asked. The diagnosis of dementia was performed according to the Diagnostic and Statistical Manual of Mental Disorders (1987).
During the 35-year study span, 161 participants developed dementia: 105 with Alzheimer’s disease (32 with cerebrovascular disease, 73 without cerebrovascular disease), 40 with vascular dementia and 16 with other types of dementias. The authors found that the women who experience frequent episodes of stress and anxiety in middle age were twice as more likely to develop dementia, especially Alzheimer’s disease. Compared to females reporting no stress, hazard ratios (95% confidence interval) for incident dementia were 1.10 (0.71–1.71), 1.73 (1.01–2.95), and 2.51 (1.33–4.77) in women reporting stress at one, two, or three examinations, respectively. The low number of cases of pure vascular dementia, as the authors mentioned, is probably linked to early mortality due to cardiovascular disease, thus underestimating the relationship between stress and vascular dementia. The mean time of dementia onset was 25 years from baseline examination.
Hospital de Clinicas Jose de San Martin, Buenos Aires, Argentina
Johansson L, Guo X, Waern M, et al. Midlife psychological stress and risk of dementia: a 35-year longitudinal population study. Brain 2010;133:2217-24.
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