The relationship between pain and depression among middle-aged and older adults in China: Functional limitation as a mediating factor

Aim The association between pain and depression has become a matter of considerable concern in public health. Nevertheless, the fundamental reasons connecting these two phenomena remain unclear. This study sought to explore whether functional limitation serves as an intermediary factor in the link between pain and depression. Materials and Methods This analysis enrolled 6046 adults aged 45 and older using data from the 2015 wave of the China Longitudinal Study of Health and Retirement (CHARLS)dataset. Statistical approaches included conducting linear regression models alongside bootstrap analyses to evaluate whether functional limitation mediated the association between pain and depression. Results In models adjusted for confounders, pain intensity showed a positive association with depressive symptoms (β = 0.271, P < 0.001) and also exhibited a positive link with functional limitation (β = 0.223, P < 0.001). The pathway between pain and depression exhibited a functional limitation that constituted 14.2% of the total effect, with the mediating pathway magnitude estimated at a*b = 0.615(95% CI: 0.521–0.720). Conclusions Our findings indicated that pain directly influences depression and also affects them indirectly through functional limitation. Interventions focused on pain management and addressing functional limitation may effectively prevent and alleviate depressive symptoms.