ASSOCIATION OF PSYCHOSOCIAL WORK STRESS WITH COGNITIVE DECLINE AND BRAIN STRUCTURE DIFFERENCES

Abstract

Evidence on the influence of psychosocial work stress on cognitive function and brain structure is limited. This study examined whether work-related stress is associated with structural brain changes and cognitive decline in old age. In a population-based prospective cohort study, 2876 dementia-free participants aged ≥60 years were followed-up for up to 9 years. A subsample (n=436) underwent brain magnetic resonance imaging (MRI) at baseline. Global cognitive function was measured by the Mini-Mental State Examination at baseline and all follow-ups. Levels of job control and demands in the longest held job over the whole working life were assessed by a validated matrix. Data were analyzed using mixed-effects linear regression. People with low levels of job control and demands exhibited greater cognitive decline (β: -0.13, 95% CI: -0.19 to -0.07; β: -0.10, 95% CI: -0.16 to -0.04), compared to those with high levels. Relative to persons who had active job strain, faster cognitive decline was found in those who had high job strain (β: -0.11, 95% CI: -0.18 to -0.05,) and passive job strain (β: -0.16, 95% CI: -0.23 to -0.09). MRI data showed that low levels of job demands and passive job strain were both related to smaller total hippocampal volume (β: -0.23, 95% CI: -0.39 to -0.08; β: -0.19, 95% CI: -0.37 to -0.01). Work-related psychosocial stress is associated with smaller hippocampal volume and may accelerate cognitive decline even in the eight decade of life, suggesting that neural alterations play a role in the work stress-cognitive decline link.