The bidirectional association between depressive symptoms and cognitive decline has been extensively studied in Western populations, yet empirical evidence from non-Western contexts, particularly among Chinese older adults, remains limited. This study aimed to examine the longitudinal and symptom-level dynamics between depressive symptoms and cognitive functioning using a cross-lagged panel network (CLPN) approach.

Data were drawn from two waves (2015, 2018) of the China Health and Retirement Longitudinal Study (CHARLS), including 6824 individuals aged 50 years and above. Cognitive performance was assessed via the China Mini-Mental State Examination (CMMSE), and depressive symptoms were measured using the 8-item Center for Epidemiological Studies Depression Scale (CESD-8). A CLPN model was estimated to identify temporally predictive pathways and symptom-level interactions, with LASSO regularization ensuring model sparsity. Model stability was evaluated through nonparametric bootstrapping.

Findings revealed a reciprocal, predominantly negative relationship between cognitive decline and depressive symptoms over time. “Mental State” (orientation, processing, and visuospatial skills) emerged as the central network hub and primary bridge from cognition to depression, while lack of motivation (“ I felt everything was an effort”) was the pivotal bridge symptom from depression to cognition. Specifically, “I felt everything was an effort” predicted subsequent declines in memory function, whereas better mental state predicted reduced depressive symptoms, including feeling depressed, trouble concentrating, and restless sleep. The network model highlighted symptom-specific pathways not observable in traditional latent variable models.

This study underscores the clinical and public health value of integrated screening and interventions targeting both depressive symptoms and cognitive impairment in older adults. Motivational deficits and mental state deficits may serve as actionable transdiagnostic targets. Future interventions should be symptom-specific, modular, and culturally sensitive. Longitudinal neurobiological studies are warranted to elucidate underlying mechanisms.