The mediating role of anxiety and depressive symptoms on the relationship between physical limitations and cognitive impairment among older adults in China: differences based on religious perspective

Background: Physical limitationsand mental health may have a common effect on cognitive function. However, little is known about how religion influences these paths among older Chinese adults. Objective: This study investigated how anxiety and depressive symptoms mediate the association between physical limitations and cognitive impairment. Furthermore, we analyzed discrepancies in path models between participants with or without religious beliefs. Methods: This population-based, cross-sectional study involved 6656 adults aged ≥60 years in six cities in Guangdong Province, China. Participants were divided into two groups based on the presence of religious beliefs. All participants completed a general demographics questionnaire, the Chinese version of the Mini-Mental State Examination (MMSE), the Basic Activities of Daily Living (BADLs) scale, Generalized Anxiety Disorder-7 (GAD-7), and Health Questionnaire-9 (PHQ-9). Simple and serial multiple mediation models were then tested using SPSS PROCESS macro. Results: BADLs, anxiety symptoms, depressive symptoms, and cognitive impairment were significantly related (all P＜0.01). When adjusting for sociodemographic and health-related factors, BADLs limitations had a direct positive effect on cognitive impairment among participants with religious beliefs (effect=0.107, 95% confidence interval (CI): 0.095, 0.121), but also had indirect effect via independent masking of anxiety symptoms (effect=-0.005, 95%CI: -0.010,-0.002). For participants without religious belief, BADLs limitations had a direct positive effect on cognitive impairment (effect=0.135, 95%CI: 0.129, 0.140) as well as an indirect effect via three paths: an independent masking effect of anxiety symptoms (effect=-0.002, 95%CI: -0.004,-0.0001), independent mediation of depressive symptoms (effect=0.003, 95%CI: 0.002,0.004), and serial mediation of anxiety and depressive symptoms (effect=0.004, 95%CI: 0.003,0.006). Conclusions: Our findings highlight the need for health professionals to promote mental well-being to prevent cognitive decline prevention among older adults with physical limitations who do not have religious belief. These findings should be further confirmed by prospective studies utilizing other methods of assessing cognitive function and religiosity.