Domain-specific physical activity and its association with depression severity in older Korean adults: insights from the 2022 Korea national health and nutrition examination survey

[Purpose] Depression is a growing mental health issue among older adults in South Korea, where rapid population aging has intensified the need for effective preventive strategies. Although physical activity is recognized as a protective factor against depression, limited research has examined how specific physical activity domains relate to depression among older Korean adults. This study investigated the associations between occupational, recreational, and commuting-related physical activity and depression severity and evaluated the effects of activity intensity and sociodemographic factors.[Methods] Data were drawn from the 2022 Korea National Health and Nutrition Examination Survey and included 1,331 adults aged 65 or older. Depression severity was assessed using Patient Health Questionnaire-9 (PHQ-9). Physical activity levels were quantified using metabolic equivalent (MET-minute) thresholds. Data were statistically analyzed using descriptive statistics, chi-square tests, and ordinal logistic regression.[Results] Of the participants, 85.27% reported no depression, while 14.73% experienced mild to severe symptoms. Chi-square analysis showed that vigorous-intensity occupational activity and moderate-intensity recreational activity were significantly associated with depression severity (<i>p</i> < 0.05). However, in the ordinal logistic regression model adjusting for covariates, only vigorous occupational activity remained statistically significant (<i>β</i> = 1.651, OR = 5.21, <i>p</i> = 0.013). Gender, household income, and education were significant predictors, whereas self-rated health and commuting activity were not. The positive regression coefficient indicated that the participants engaging in vigorous-intensity occupational activity had higher odds of belonging to more severe depression categories.[Conclusion] These findings highlight the importance of designing tailored interventions for vulnerable subgroups, including older women individuals with a low socioeconomic status.