Psychological distress contributes to increased dementia risk

Individuals with symptoms of psychological distress are at increased risk of all-cause dementia, although this association is attenuated by the competing risk of death, according to a study.

The study used data from the population-based cross-sectional National FINRISK Study and included 67,688 participants (mean age 45.4 years, 51.7 percent women). All of them completed surveys that inquired about symptoms of psychological distress, including stress (more than other people), depressive mood, exhaustion, and nervousness (often, sometimes, never). Surveys were collected at several time points (1972, 1977, 1982, 1987, 1992, 1997, 2002, and 2007).

Researchers applied Poisson cause-specific hazard model and Fine–Gray subdistribution hazard model to examine psychological distress in relation to the aetiological risk of dementia and incidence of dementia in the presence of competing risk of death.

Over a mean follow-up of 25.4 years, 7,935 developed dementia. Analysis revealed a significant association between psychological distress and all-cause dementia. The incidence rate ratios of dementia associated with exhaustion and stress were 1.17 (95 percent confidence interval [CI], 1.08–1.26) and 1.24 (95 percent CI, 1.11–1.38), respectively. These associations persisted in sensitivity analyses.

Further analysis revealed the association of dementia risk with symptoms other than depressive mood (hazard ratio [HRs], 1.08, 95 percent CI, 0.98–1.20). The HRs associated with exhaustion and stress were 1.08 (95 percent CI, 1.01–1.17) and 1.12 (95 percent CI, 1.00–1.25), respectively. All symptoms had significant associations with competing risk of death in both Poisson and Fine–Gray models.