Exploring the mediating role of depression and anxiety in the relationship between social and biological factors and quality of life in Indonesia: A structural equation modelling approach

Objectives To examine the association between social and biological factors and quality of life (QoL), and whether depression and anxiety mediate this relationship. Design Cross-sectional study with individual level as the unit of analysis. Main outcome measures Depression and anxiety were measured using the Center for Epidemiologic Studies Short Depression scale and Generalized Anxiety Disorder scale, while QoL was assessed using the EuroQol Five-Dimension scale. Social factors were assessed using the self-reported number of close persons, and biological factors were measured using the number of self-reported physical health comorbidities. Setting Country-level data. Participants General population aged 18 and older with data available. Results Among participants, 849 (4.42%) had depression and 2339 (12.17%) had anxiety. Structural equation modelling (SEM) analysis, adjusted by age and sex, showed that social factors (β=-0.004, p<0.001) and biological factors (β=-0.051, p<0.001) were directly associated with QoL. Mediation analysis revealed that depression and anxiety fully mediated the relationship between social factors and QoL. For biological factors, depression and anxiety partially mediated the relationship with QoL, accounting for 29.30% and 22.83% of the total effect, respectively. Conclusions Depression and anxiety mediate the relationship between social and biological factors and QoL. Strengthening social support and improving mental health access can mitigate these risks. Future research should examine long-term trends and intervention effectiveness to inform targeted policies for at-risk populations.