A Study on the Longitudinal Relationship between Changes in Depression and Cognitive Function among Older Adults Living Alone

Background: As South Korea faces unprecedented population aging, this longitudinal study examined the relationship between depression and cognitive function changes in older individuals living alone. Methods: The study used data from the Korean Longitudinal Study of Aging (KLoSA). A total of 1354 participants with data available over a period of at least three years, from 2016 (wave 1) to 2020 (wave 8), were included, and latent growth modeling (LGM) was used for analysis. Results: Depression levels increased gradually among older individuals living alone and cognitive function declined over time among older adults living alone. Moreover, higher initial depression levels were associated with lower initial cognitive function levels and a more rapid cognitive decline over time. Therefore, it is imperative that depression be addressed as a potential cause of cognitive impairment and dementia. Furthermore, rapid increases in depression corresponded to rapid declines in cognitive function, indicating the need for continuous monitoring and intervention in cases of escalating depression, as it may negatively affect cognitive abilities. Conclusions: These findings highlight the complex interplay between depression and cognitive function among older individuals living alone. Policy support to encourage participation in these programs is crucial to enhance the well-being of this vulnerable population.