Noticeable demographic changes have taken place in South Korea, with the general marriage rate decreasing and the average first age at marriage and general divorce rate increasing. The shown trends have contributed to intergenerational discordance in the perception of familial values, which is important in addressing the psychological well-being of parents. This study aimed to investigate the association between the marital status of offspring aged 40 years and over and the depression levels of parents.

Data were from the Korean Longitudinal Study of Aging (KLoSA), 2006–2012. A total of 2,540 individuals with at least two offspring aged 40 years and over were included. Association between offspring marital status and parental depression scores, measured using the Center for Epidemiological Studies and Depression (CES-D 10) scale, was investigated using the generalized estimating equation (GEE) model. Subgroup analysis was performed based on offspring education level.

When parents with only married offspring were set as reference, parents with never married offspring (β: 0.27, p = 0.02), parents with separated offspring (β: 0.52, p = 0.03), and parents with never married offspring and separated offspring (β: 0.38, p < 0.001) showed increases in depression scores. In the subgroup analysis, these higher depression score effects were largely limited to parents with high school graduate offspring.

It is important to monitor the mental health status of parents with never married, separated, or both never married and separated offspring as this group may be comparatively vulnerable to depressive symptoms.