The μ-Opioid System and Antidepressant ResponseByHolly A. Garriock, PhD,Steven P. Hamilton, MD, PhDApril 16th 2008This article discusses the role of µ-opioid receptors (MORs) in antidepressant treatment and major depressive disorder (MDD). Specifically, it focuses on how the endogenous opioid system affects response to pharmaceuticals.