Linking Physical Activity to Depression Management in Primary Care: Evidence from Korea

The 2023 Korea Community Health Survey found an inverse association between the frequency of moderate-to-vigorous physical activity and depressive symptoms in adults—supporting consideration of activity frequency when assessing depressive risk and integrating brief activity questions into depression workflows.

In this cross-sectional analysis of 228,249 adults aged ≥19 years, item-level PHQ-9 responses (0–3 per item; total 0–27) quantified depressive symptom burden. Physical activity was measured as days per week (0–7) of moderate and vigorous activity per KCHS definitions; primary outcomes were weighted mean PHQ-9 item scores and group differences across PA-frequency categories (0, 1–2, 3–4, 5–7 days).

Descriptive results showed lower PHQ-9 item scores with higher activity frequency: those active 5–7 days/week had the lowest mean item scores (1.12–1.34) versus 0 days (1.25–1.48). Mean differences across PA categories were small (≈0.02–0.12 points on the 0–3 item scale; η2 < 0.06) but statistically significant (p < 0.001). Analyses were descriptive and unadjusted; adjusted estimates were not reported, limiting causal inference.

Sociodemographic gradients were evident: women, adults aged ≥60 years, bereaved individuals, and those with lower educational attainment reported higher depressive symptoms and lower activity (all p < 0.001). Effect sizes for sex (η2 = 0.02–0.06) and age (η2 = 0.03–0.08) were noted. Men reported about 0.36 and 0.45 more mean days/week of moderate and vigorous activity, respectively. These patterns identify priority populations for intensified screening and low-cost activity supports.

The survey captured frequency but not session duration; higher frequency—especially 5–7 days/week—aligned with the lowest symptom scores, so the data support frequency-based recommendations but do not speak to short versus long sessions. This distinction allows counseling that emphasizes brief, regular activity breaks rather than prescribing specific session lengths, while acknowledging measurement limits.

For primary care, a single-item days-per-week activity question added to the PHQ-9 can efficiently flag patients with low activity for brief counseling or referral. Implementation options include embedding the item in intake forms, using a short script to link activity to mood, and providing printed or digital lists of local walking groups and online programs. A simple behavioral approach—assess frequency, set an achievable target (for example, increase to 3 days/week), and arrange follow-up—fits routine workflows and local referral resources.