MMP9 and major depressive disorder: The expression of autophagy‐related genes (Atg5, Atg7, Atg12, Becn1, Mmp9, Fkbp5, and Map1lc3b), which are reported to be upregulated in the brains of MDD patients [25, 26, 27], were examined in the hippocampus and midbrain of control and depression model mice.