PCSK1N and major depressive disorder: We observed no obvious differences between different MDD patients on different treatment protocols and decreased levels of LINGO1 [61–73], GRIA4 [217–229], CNTNAP4 [886–897], SERPINI1 [287–293], PCSK1N [201–215], NPTXR [234–251], CARTPT [75–90], and NRXN3 [1242–1254] in all MDD subgroups in comparison to the controls (Supplementary Fig. 4).