Individuals with a retrospective diagnosis of MDD (n = 633 vs. 10,916 controls), or more broadly, at least two weeks of sustained self-reported depressive symptoms (broad depression, n = 18,494 vs. 18,847 controls) prior to the baseline blood sample confirmed a relationship between depression and glycoprotein acetylation, platelet count, pyruvate, Vitamin D, and RBC levels (Supplementary Fig. S2 and Table S9). Here, ART4 is linked to major depressive disorder.