Association between depression and cognitive function in middle-aged and older adults: a study based on the health and retirement study

Objective To describe the distribution of depression and cognitive function status among adults aged 50 years and older, identify factors associated with cognitive function status, and examine the association between depression and cognitive function as well as the potential mediating roles of anxiety, health status, and eyesight. Methods Cross-sectional data from 3,434 participants aged 50 years and older in the 2022 Health and Retirement Study were analyzed. Cognitive function was assessed using the TICS-27, depression using the 8-item CES-D, and anxiety using the 5-item BAI. Univariate analyses, multivariate ordered logistic regression, and mediation analyses were performed. Results Among participants, 83.8% were cognitively normal, 13.7% had cognitive impairment no dementia (CIND), and 2.4% had dementia. Ordered logistic regression showed that age, race, educational level, marital status, total household income, eyesight, BMI category, and depression were significantly associated with cognitive function status. Compared with participants aged 50–59 years, those aged 70–79 years and ≥80 years had higher odds of being in a worse cognitive function category (OR = 2.156 and 3.776, respectively). Depressed participants were more likely to have worse cognitive function status than non-depressed participants (OR = 1.990). Anxiety, health status, and eyesight partially mediated the association between depression and cognitive function, accounting for 25.66, 32.19, and 15.19% of the total effect, respectively. Conclusion Depression was significantly associated with worse cognitive function status among middle-aged and older adults, and anxiety, health status, and eyesight may partially explain this association. These findings highlight the importance of considering psychological, general health, and sensory factors in the early identification and comprehensive intervention of cognitive decline.