The Effect of Stress on All-Cause Dementia: A Longitudinal Analysis From the Australian Longitudinal Study on Women's Health.

OBJECTIVES

Perceived stress has been linked to dementia, however the duration of perceived stress, as well as the timing of this exposure, on dementia has not been explored. This study aimed to assess the effect of transient versus prolonged versus persistent perceived stress and exposure to stressful life events (SLE), as well as time windows of exposure, on all-cause dementia.

DESIGN

Cohort study.

SETTING

The Australian Longitudinal Study on Women's Health (ALSWH).

PARTICIPANTS

The oldest cohort (born 1921-26), and the middle cohort (born 1946-51), from the Australian Longitudinal Study on Women's Health were used in this analysis.

MEASURES: Perceived stress and SLE were measured using a self-reported questionnaire. Dementia was defined as per International Classification of Disease - 10 (ICD 10) codes through linked datasets over a mean follow up of 16 years for the oldest and 20 years for the middle cohort.

RESULTS

Transient, prolonged and persistent perceived stress were associated with increased risk of all-cause dementia (HR: 1.52, 95% CI: 1.04-2.23, HR: 1.63, 95% CI: 1.15-2.27, and HR: 1.65, 95% CI: 1.10-2.50 respectively) in the middle cohort. Higher risk of all-cause dementia was found among middle cohort exposed to four or more SLE, however the association was statistically insignificant in the fully adjusted model. Both perceived stress and SLE had no effect in the oldest cohort.

CONCLUSION

Transient, prolonged and persistent perceived stress were associated with higher risk of all-cause dementia in our middle cohort which suggests that stress may be a risk factor for dementia.