CRP and major depressive disorder: After adjusting for age, sex, educational levels, income levels, smoking status, alcohol use, physical activity status, hypertension, diabetes mellitus, kidney disease, c-reactive protein, and total energy intake (per 1000 kcal), the result showed a protective effect against depression (OR = 0.378, 95% CI 0.155 to 0.924) and inferiority (OR = 0.305, 95% CI 0.102 to 0.912).