Depressive Symptoms as Mediator on the Link between Physical Activity and Cognitive Function: Longitudinal Evidence from Older Adults in China

ABSTRACT

Objectives

This study examines the extent to which depressive symptoms mediate the link between physical activity and cognitive function among older adults in China.

Methods

This study utilizes the 2013–18 China Health and Retirement Longitudinal Study (CHARLS) dataset, of which 3,658 subjects over the age of 50 satisfied inclusion criteria. Degree of physical activity, prevalence of depressive symptoms, and performance in cognitive function are measured by the International Physical Activity Questionnaire (IPAQ), Center for Epidemiological Studies Depression Scale (CESD), the Mini-Mental State Examination (MMSE) instruments. A structural mediation model was built to assess the degree to which depressive symptoms act as mediator between physical activity and cognitive function.

Results

Physical activity is positively and significantly associated with cognitive function (std β = 0.034, p-value = .007), while physical activity is negatively and significantly associated with prevalence of depressive symptoms (std β = −0.088, p-value < .001). Results indicate that depressive symptoms partially and significantly mediate the relationship between physical activity and cognitive function (std β = 0.003, p-value = .035). Total influence of physical activity on cognitive performance is evaluated to be 0.037 standard deviations (p-value = .035).

Conclusions

Findings uncover an underexamined mental well-being channel through which physical activity can positively influence late adulthood cognition.

Clinical Implications

In recommending behavioral modifications to reduce risks of late adulthood cognitive decline, encouraging physical activity for older individuals is key, since it is both directly associated with better cognitive performance, as well as indirectly through lowering prevalence of depressive symptoms.

KEYWORDS:

• Aging
• mini-mental state examination
• China
• dementia
• depression

Authors’ contribution

J.L., Q.C., and J.D. conceived, conceptualized, and designed the study. J.L. and Q.C. contributed to statistical analysis. J.L., F.Q., Q.C., and J.D. drafted the article and contributed to interpretation of results. All authors have revised the manuscript for important intellectual content and have read and agreed to the present version of the manuscript.

Data Availability statement

Restrictions apply to the availability of data used, due to study subject privacy protection. Deidentified participant data is available upon reasonable request to the corresponding author, with permission of CHARLS group at Peking University. http://charls.pku.edu.cn/en/

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethics Approval and Consent to Participate

The study was conducted according to guidelines of the Declaration of Helsinki and approved by the Institutional Review Board at Peking University (IRB00001052-11015). All subjects’ consent to participate in the study was obtained.

Additional information

Funding

This work was supported by Natural Science Basic Research Program of Shaanxi (2022JQ-200).