Multidimensional deprivation and depressive symptom trajectories among single-person households in South Korea: an age-stratified longitudinal study

Abstract Background The rapid growth of single-person households represents a major demographic shift with significant implications for public mental health. Adults living alone may be particularly vulnerable to depression due to reduced social support and heightened exposure to various forms of disadvantage. While the link between socioeconomic status and mental health is well-documented, there is a need for longitudinal evidence that accounts for the multidimensional nature of deprivation across different life stages. This study examined the age-stratified associations between multidimensional deprivation and depressive symptom trajectories among adults living alone. Methods Data were drawn from six waves (2018–2023) of the Korea Welfare Panel Study (KOWEPS), including 2,094 adults (aged ≥ 20) in single-person households. Depressive symptoms were assessed repeatedly using the CESD-11. Multidimensional deprivation was operationalized across six domains: basic living, housing, social security, employment/economic status, social relationships, and healthcare. Latent growth modeling (LGM) was employed to estimate initial levels and rates of change in depressive symptoms. To identify age-specific patterns, analyses were conducted separately for young, middle-aged, and older adults. Results Depressive symptoms among single-person households showed a significant upward trajectory over time. In age-stratified analyses, the associations between multidimensional deprivation domains and depressive symptoms varied across life stages. Basic living deprivation was more strongly associated with depressive symptoms among young adults, whereas economic and healthcare deprivation were more strongly associated among middle-aged adults. For older adults, housing and healthcare deprivation showed stronger associations with depressive symptom levels. Notably, social relationship deprivation was consistently associated with both baseline levels and trajectories of depressive symptoms across all age groups. Conclusions The longitudinal progression of depressive symptoms in single-person households is associated with multidimensional deprivation, with varying impacts across the life course. These findings suggest that public health interventions for those living alone should move beyond a one-size-fits-all approach and instead implement age-specific, multidimensional strategies. Particular focus should be placed on addressing social connectivity and healthcare access, which remain important factors in mental health across all stages of adulthood.