Subtypes of Depressive Symptoms and Their Relationship to Suicide Ideation Among Korean Older Adults

Purpose: Late-life depression is one of the important health issues in older adults because it is frequently untreated. Untreated late-life depression is a risk factor for suicide among older adults. In addition, research reports gender differences both in patterns of depressive symptoms and their relationships to suicide ideation. However, little is known about subtypes of depressive symptoms and their impacts on suicide ideation among Korean older adults. The purpose of the present study was to (a) identify the underlying subgroups of Korean older adults who had similar patterns of depressive symptoms, (b) explore gender differences in subtypes of depressive symptoms, and (c) examine the relationships between identified subtypes of depressive symptoms and suicide ideation. 

Method: The data used in the present study from the 2015 Korean Welfare Panel study (KOWEPS). A total of 4,823 older adults aged 65 and over (1,796 males and 3,027 females) were included in the analysis. To examine the subtypes of depressive symptoms, the 11-item Center for Epidemiologic Studies Depression (CES-D) were utilized. Latent Class Analysis (LCA) was conducted to explore the underlying patterns of depressive symptoms among Korean older adults. A multigroup-LCA was also performed to examine measurement invariance across gender. Lastly, a series of logistic regression was employed to examine the relationships between subtypes of depressive symptoms and suicide ideation among Korean older adults after adjusting for socio-demographic characteristics (e.g., age, gender, education). The model fit was evaluated by the Bayesian Information Criteria, the size of the smallest group, solution stability, and the interpretability for practical purposes. All analyses were conducted using SAS 9.4 and Mplus 7.4, after adjusting for sampling weights.

Results: Six distinct subtypes of older adults were found: (1) no depressive symptoms (43.3%), (2) all depressive symptoms (6.1%), (3) most depressive symptoms without interpersonal symptoms (16.5%), (4) depressive affect and somatic symptoms (13.6%), (5) negative affect and somatic symptoms (9.8%), and (6) somatic symptoms only (10.8%). A multigroup-LCA shows that measurement invariance holds across gender. However, the prevalence of latent classes was different across gender. Women were more likely to belong to groups with depressive symptoms compared to men. Lastly, an interaction effect between gender and subtypes of depressive symptoms on suicide ideation was found that men with negative affect and somatic symptoms were more likely to have suicide ideation in the past year than their counterparts.

Conclusion and Implications: Findings highlight six distinctive subgroups of Korean older adults who had similar patterns of depressive symptoms and their relationships to suicide ideation. Findings also found that male older adults with specific depressive symptoms were more likely to have suicide ideation in the past year than their female counterparts. These findings may suggest that some depressed male older adults are more vulnerable to suicide than depressed female older adults. Identifying subtypes of depressive symptoms may be useful to understand older adults who are more vulnerable and to develop tailored interventions.