Major Depressive Disorder Pending FDA approval for treatment of major depressive disorder Mechanism of Action Serotonin (5HT)-1a agonist; activation of 5HT-1a leads to glutamate inhibition; without glutamate activation of GABA interneurons, there is no inhibitory control over dopamine release, thereby, increasing dopamine release No images available for this drug. No images available for this drug.A Patient Handout is not currently available for this monograph.Print