GAST and major depressive disorder: A correlation analysis was performed on the predictive variables of our model, which included gender, age, level of education, marital status, obesity, hypertension, depression, frailty, alcohol consumption, smoking, diabetes, dyslipidemia, family history, HP infection, glucose, cholesterol, pepsinogen I, pepsinogen II, gastrin 17, AFP, CEA, CA125, CA199, D-dimer, Kimura–Takemoto classification, and bile reflux.