Patterns of Physical Activity and Depressive Symptoms Among Korean Adults: A Descriptive Cross-Sectional Analysis of the 2023 Korea Community Health Survey

<b>Background/Objectives:</b> Depression has increased substantially in Korea following the COVID-19 pandemic, with prevalence reaching 7.3% in 2023, the highest level in a decade, raising urgent concerns about widening mental health disparities. Although physical activity (PA) is associated with reduced depressive symptoms, nationally representative post-pandemic evidence from Korean adults remains limited. This study descriptively examined patterns of PA participation and depressive symptoms across key sociodemographic groups using 2023 Korea Community Health Survey (KCHS) data. <b>Methods:</b> We analyzed cross-sectional data from 228,249 adults aged ≥19 years in the 2023 KCHS. Depressive symptoms were measured using nine PHQ-9 items (1-4 on Likert scale). PA was assessed as the number of days per week (0-7) of moderate (MPA) and vigorous (VPA) physical activity according to KCHS operational definitions. All analyses incorporated complex survey features (strata, clusters, weights). Group differences were examined using design-corrected <i>t</i>-tests and ANOVA. <b>Results:</b> Women, adults aged 60 years or older, bereaved individuals, and those with lower educational attainment reported higher depressive symptom levels (<i>p</i> < 0.001). PA participation was higher among men, younger adults, married individuals, and those with higher education. Depressive symptom scores decreased with increasing PA frequency, with the lowest levels observed among adults active 5-7 days per week. Although mean differences were modest (0.02-0.12 points on the four-point scale; η² < 0.06), these steady population-level gradients provide meaningful baseline information for understanding post-pandemic mental health patterns in Korea. <b>Conclusions:</b> Although individual-level differences were small (η² < 0.06), the population-level gradients are important for monitoring mental health disparities in post-pandemic Korea. Women, older adults, bereaved individuals, and lower-education groups represent key high-burden populations. Future studies should employ longitudinal designs, objective PA measures, and confounder-adjusted models to clarify mechanisms and directionality, and evaluate the effectiveness of community-based PA interventions.