Abstract
OBJECTIVES: We examined associations between job strain and trajectories of change in cognitive functioning (general cognitive ability plus verbal, spatial, memory, and speed domains) before and after retirement. METHOD: Data on indicators of job strain, retirement age, and cognitive factors were available from 307 members of the Swedish Adoption/Twin Study of Aging (SATSA).
Participants were followed for up to 27 years (mean=15.4, SD=8.5). RESULTS: In growth curve analyses controlling for age, sex, education, depressive symptoms, cardiovascular health, and twinness, greater job strain was associated with worse memory (Estimate=-1.22, p=.007), speed (Estimate=-1.11, p=.012), spatial ability (Estimate=-0.96, p=.043), and general cognitive ability (Estimate=-1.33, p=.002) at retirement.
Greater job strain was also associated with less improvement in general cognitive ability before retirement and a somewhat slower decline after retirement. The sex-stratified analyses showed that the smaller gains of general cognitive ability before retirement (Estimate=-1.09, p=.005) were only observed in women.
Domain-specific analyses revealed that greater job strain was associated with less improvement in spatial (Estimate=-1.35, p=.010) and verbal (Estimate=-0.64, p=.047) ability before retirement in women, and a slower decline in memory after retirement in women (Estimate=0.85, p=.008) and men (Estimate=1.12, p=.013). Neither pre-retirement nor post-retirement speed was affected by job strain.
DISCUSSION: Greater job strain may have a negative influence on overall cognitive functioning prior to and at retirement, while interrupting exposure to job strain (post-retirement) may slow the rate of cognitive aging. Reducing level of stress at work should be seen as a potential target for intervention to improve cognitive aging outcomes.