Examining the association between neck pain and depressive symptoms in middle-aged and older Chinese adults: findings from the China Health and Retirement Longitudinal Study (CHARLS).

BACKGROUND: Neck pain is a prevalent musculoskeletal condition among middle-aged and older adults and may contribute to the development of depressive symptoms. However, evidence on the longitudinal relationship between neck pain and depression remains limited in large population-based cohorts. METHODS: Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS), including adults aged ≥ 45 years who participated in the 2011 baseline survey. Cross-sectional associations between neck pain and depressive symptoms were evaluated using multivariable logistic regression, while longitudinal associations over a 9-year follow-up (2011–2020) were examined using Cox proportional hazards models. An elastic net (ENET) regularization method was used for predictor selection. Subgroup and interaction analyses were performed to assess effect modification, and E-values were calculated to evaluate robustness to unmeasured confounding. RESULTS: At baseline in 2011, 9,452 participants (mean age 59.11 ± 9.56 years; 49.97% women) were included in the cross-sectional analysis, and 3,530 participants free of depressive symptoms at baseline were included in the longitudinal analysis. In cross-sectional analyses, neck pain was independently associated with increased odds of depressive symptoms (adjusted OR = 3.019, 95% CI: 2.341–3.899). In longitudinal analyses, neck pain predicted a higher risk of developing depressive symptoms over time (adjusted HR = 1.102, 95% CI: 1.081–1.124). Subgroup analyses confirmed the robustness of these associations across sociodemographic and health strata, with no significant interactions observed. Sensitivity analysis showed moderate to strong resistance to unmeasured confounding. CONCLUSION: Neck pain is significantly associated with the presence and future development of depressive symptoms in middle-aged and older Chinese adults. These findings highlight the importance of early identification and integrated management of neck pain in efforts to prevent late-life depression.