Multiple Trajectories of Depressive Symptoms and Their Predictors Among Older Adults in Poverty

Purpose: Late-life depression has received growing national attention in South Korea due to the high prevalence of depression in older adults. The prevalence of depression has been reported to be ranged from 20% to 50%. Furthermore, the suicide rate of Korean older adults was four times higher than the OECD average. Up to date, a number of studies have examined the association between depression and its related factors and have explored the changes of depression symptoms. Those studies have consistently reported that the poor elderly is the most vulnerable to depression. However, little is known about the developmental course of depressive symptoms over time among older adults in poverty and whether distinct patterns of depression symptoms exist among this population. This study aims to analyze the multiple trajectories of depressive symptoms among the elderly in poverty and to identify profiles of depressive symptoms predicting different trajectories.

Method: This study uses five waves of longitudinal data from Korean Welfare Panel Study (KWPS) which is a nationally representative study. Subjects were selected based on three criteria: aged 60 and over, below 60% of median household income, and completed at least three waves between 2006 and 2010. Finally, this study analyzed 2,594 respondents. Depressive symptoms were measured by the Korean short version of Epidemiologic Studies Depression Scale. The latent growth mixture model and the multiple logistic regression model were used for data analysis.

Results: After controlling variables such as gender, age, education, marital status, and self-assessed health, this study identified four different trajectory classes: stable low depressive symptoms (69.8%), high but decreased depressive symptoms (11.0%), moderate but increased depressive symptoms (10.6%), and increased but decreased pattern of depressive symptoms (8.6%). The elderly in stable low trajectory had better health status, higher self-esteem and good relationship with family members. On the other hand, older adults who belonged to the risk patterns of depression were associated with being older, living without any spouse, having shorter working periods, and the elderly living in lower income level.

Conclusion and Implications: This study suggests that there is longitudinal heterogeneity in depression among the Korean elderly in poverty. Although most of the elderly in poverty belonged to the trajectory of relative low stability, the proportion of the poor elderly people who experienced moderate or high level of depression reached at approximately 30%, which is higher than that of the prior research including both poverty and non-poverty elderly. The results of this study highlight the importance of focusing on preventive factors identified in this study, namely, self-esteem and family relationship. Furthermore, interventions are necessary targeting those who have the high likelihood of developing depression: these populations consist of the oldest-old persons, living without any spouse, and the poorest elderly. These findings provide important information to target subjects at higher risk in order to prevent the negative depression process, and improve the intervention and prevention to reduce depression symptoms for elderly in poverty.