The depression and non-depression groups differed significantly in relation to age, educational level, per capita monthly household income, current work status, current smoking status, current drinking status, regular physical activity, duration of diabetes, hypertension, chronic kidney disease, stroke, fatty liver, diabetic nephropathy, diabetic retinopathy, insulin use, HbA1c, and social support (P < 0.05). The gene discussed is INS; the disease is diabetic retinopathy.