Background: Depression is highly prevalent in older adults and has been consistently associated with cognitive impairment. However, evidence on how depression relates to specific cognitive domains remains scarce, particularly in middle-income countries. We aimed to evaluate the association between depression and cognitive performance across multiple domains among older adults and identify which depressive symptoms are associated with worst performance.

Methods: Cross-sectional analyses of the ELSI-Brazil baseline, a nationally representative sample of Brazilians aged 50 years and older. Depression was defined through a CESD-8 ³ 4. Cognitive functions were: 10-word list with immediate and delayed recall, verbal fluency and total cognition, transformed in an standardized (age, sex and education) z-score. Linear regression models were applied to assess the association between depression and cognitive domain scores, estimating beta coefficients, adjusted for age, sex, education, household income, number of chronic illnesses, sedentarism, current smoking, and current drinking. An adjusted linear regression was also applied to verify which CES-D-8 item were associated with total cognition score.

Results: 7962 participants were included. Individuals with depression were younger, more frequently female, had lower educational attainment and household income and a higher burden of chronic illnesses (all p < 0.001). Depressed participants exhibited significantly worse performance across all cognitive domains. 

 

In linear regression models, depression was consistently associated with poorer cognitive performance across all domains, with immediate memory recall (β = -0.19 ; 95% CI: -0.26 to -0.14), delayed memory recall (β = −0.25; 95% CI: −0.32 to −0.19), combined memory recall (β = −0.26; 95% CI: −0.31 to −0.19), and total cognition (β = −0.36; 95% CI: −0.42 to −0.30). CES-D items 6 - Enjoyed life (β = −0.18; 95% CI: −0.25 to −0.11)), 7 - Felt sad (β = −0.15; 95% CI: −0.24 to −0.07) and 8 - Could not get going (β = −0.22; 95% CI: −0.29 to −0.15) were associated with worst total cognition. 

Conclusion: Depression was independently associated with worse cognition across all evaluated domains, with some specific depressive symptoms associated with worst overall cognition.