In the logistic regression analysis, serum magnesium levels were related to lower ORs of depression in those with CRP levels ≥ 5 mg/L (OR = 0.11; 95% CI = 0.02, 0.69; p = 0.018), but its association to lower ORs of depression was not statistically significant in those with CRP levels < 5 mg/L (OR = 0.51; 95% CI = 0.19, 1.39; p = 0.186). The gene discussed is CRP; the disease is depressive symptom measurement.