We included peripheral biomarkers (e.g., thyroid hormone, hemoglobin, white blood cells, platelets, aspartate aminotransferase, and alanine aminotransferase), psychosocial functioning (e.g., EQ-5D), and sociodemographic variables (e.g., age, sex, marital status, educational level, and economic status) to classify depression. The gene discussed is GPT; the disease is major depressive disorder.