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

Among 10,370 community-dwelling older adults, 23.95% had mild cognitive impairment and 16.44% had major cognitive impairment (dementia-level).

• Sample consisted of 4,590 males and 5,780 females aged 65-103 years, with mean age 73.41 ± 6.67 years.
• Data were collected from a cross-sectional survey in Guangxi, China, conducted between July 2022 and July 2023.
• Cognitive function was assessed using the Memory Impairment Screen (AD8).
• 233 participants (2.25%) had co-existing anxiety and depression.

Depression symptoms were positively correlated with cognitive impairment.

• Correlation coefficient r = 0.361, P < 0.001.
• Depression was assessed using the Patient Health Questionnaire-9 (PHQ-9).
• Multiple regression analysis confirmed depression (PHQ-9) significantly influenced cognitive function (P < 0.05).

Anxiety symptoms were positively correlated with cognitive impairment.

• Correlation coefficient r = 0.287, P < 0.001.
• Anxiety was assessed using the Generalized Anxiety Disorder Scale-7 (GAD-7).
• Multiple regression analysis confirmed anxiety (GAD-7) significantly influenced cognitive function (P < 0.05).

Age was positively associated with cognitive decline.

• Correlation coefficient r = 0.213, P < 0.001.
• Age was identified as a significant factor influencing cognitive function in multiple regression analysis (P < 0.05).

Mental health partially mediated the relationship between age and cognitive function.

• The total effect of age on cognitive function was 0.055 (P < 0.001).
• The direct effect of age on cognitive function was 0.04 (P < 0.001).
• Chain mediation analysis was employed to investigate this relationship.
• The mediation was partial, indicating age also has a direct effect on cognitive decline independent of mental health.

Gender, education, and marital status were also significant factors influencing cognitive function.

• Multiple regression analysis revealed that gender, age, education, marital status, depression (PHQ-9), and anxiety (GAD-7) all significantly influenced cognitive function (P < 0.05).
• Linear regression, correlation analysis, and chain mediation analysis were employed to investigate these relationships.