opiod system
Spotlight: Antidepressants and the endogenous opioid system (Fricker, et al, 2025)
"A growing body of evidence links the opioid system w/ major depressive disorder... two different widely used antidepressants, tianeptine & ketamine, both interact with MOR; tianeptine as a full agonist, ketamine as a positive allosteric modulator. Both produce antidepressant effects within days."