Heterogeneity of depressive symptoms and associated factors in Korean adults: a latent class analysis using a...

This study aimed to identify latent classes of depressive symptoms among Korean adults and to examine the sociodemographic and biobehavioral factors associated with each subgroup.

This secondary analysis used data from 4,646 adults who participated in the 2022 Korea National Health and Nutrition Examination Survey. Latent class analysis was applied to the 9 items of the Patient Health Questionnaire-9 to identify distinct subgroups. Multinomial logistic regression was then performed to determine the factors associated with class membership.

Three distinct latent classes were identified: the low-risk group (61.1%), the somatic symptom group (31.0%), and the global depression group (7.9%). The somatic symptom group, which comprised the largest proportion of symptomatic individuals, was characterized predominantly by physical complaints. In contrast, the global depression group showed high probabilities across all symptom domains. Female sex and shorter sleep duration emerged as shared risk factors for both depressive classes. However, unhealthy lifestyle behaviors, including high-risk drinking and obesity, were associated exclusively with the global depression group, compared with the low-risk group, and were not associated with the somatic symptom group.

These findings confirm the heterogeneity of depressive symptoms among Korean adults. Notably, unhealthy lifestyle behaviors such as high-risk drinking and obesity were associated with the most severe global manifestation of depression rather than with the somatic subtype. These results support the need for stratified interventions. Although sleep hygiene education may serve as a universal preventive strategy, targeted lifestyle modifications may be particularly important for individuals in the high-risk global depression group.