GPT and major depressive disorder: Adjusted models demonstrated that each 1-unit increase in ALT/AST ratio was associated with a 106% higher risk of depression (OR = 2.06, 95% CI: 1.41–3.01; P < 0.001), whereas each 1-unit increase in BUN and BUN/Cr ratio corresponded to 16% (OR = 0.84, 95% CI: 0.79–0.89) and 4% (OR = 0.96, 95% CI: 0.94–0.98) decreased risks, respectively (P < 0.001).