The Associations Between Income and Depression: A Cross-National Analysis.

Depression remains one of the most prevalent global mental health challenges, while prior research has often examined its determinants through fragmented and isolated perspectives. A multidimensional understanding of how biological, psychological, social, and sociocultural factors jointly shape depression risk remains limited, particularly across national contexts. Using data from three nationally representative cohorts in the United Kingdom (Understanding Society: The UK Household Longitudinal Study), the United States (Midlife in the United States), and China (China Health and Retirement Longitudinal Study), we applied network analysis and parallel mediation analysis to examine the relative importance of multidimensional factors associated with depression and to assess pathways associated with income and depressive symptoms. Across all cohorts, psychological factors showed the strongest associations with depression. Lower income was directly related to higher depression and indirectly related through parallel pathways involving loneliness and disability. Loneliness emerged as the most consistent mediator across cohorts. These findings provide an integrated view of depression risk and highlight the potential role of psychological mechanisms in linking socioeconomic disadvantage to mental health vulnerability across populations.