DPP4 and type 2 diabetes mellitus: The glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-IV (DPP-IV) inhibitors showed anti-inflammatory properties in humans and exerted a reduction in the depressive symptoms of newly diagnosed type 2 diabetic patients with major depression, suggesting that a reduction in inflammation might provide antidepressant effects [60].