Associations between mental health and cognitive function among community-dwelling older adults: a large-scale cross-sectional study.

BACKGROUND

To explore the associations of depression and anxiety with cognitive function in older adults, and the potential mediating role of mental health.

METHODS

Data were collected from a cross-sectional survey of community-dwelling older adults in Guangxi, China, conducted between July 2022 and July 2023. Valid data from 10,370 participants aged 60 years and older were analyzed. Cognitive function was assessed using the Memory Impairment Screen (AD8), while depression and anxiety symptoms were evaluated using the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder Scale-7 (GAD-7), respectively. Linear regression, correlation analysis, and chain mediation analysis were employed to investigate the relationships among age, mental health, and cognitive function.

RESULTS

Among the 10,370 participants (4,590 males and 5,780 females, aged 65-103 years, mean age: 73.41 ± 6.67 years), 23.95% had mild cognitive impairment (MCI), and 16.44% had major cognitive impairment (dementia-level), and there were 233 participants (2.25%) with co-existing anxiety and depression. Multiple analysis revealed that gender, age, education, marital status, depression (PHQ-9), and anxiety (GAD-7) significantly influenced cognitive function (P < 0.05). Both depression and anxiety symptoms were positively correlated with cognitive impairment (r = 0.361 and r = 0.287, respectively, P < 0.001). Age was also positively associated with cognitive decline (r = 0.213, P < 0.001). Mediation analysis indicated that mental health partially mediated the relationship between age and cognitive function, with a significant total effect (0.055, P < 0.001) and direct effect (0.04, P < 0.001).

CONCLUSIONS

Mental health partially mediates the link between age and cognitive decline, offering new insights for developing interventions to support cognitive function and quality of life in older adults.