 - Be receiving monotherapy treatment for depressive symptoms with 1 of the following selective serotonin reuptake inhibitor SSRIserotonin-norepinephrine reuptake inhibitor SNRI antidepressants, in any formulation: citalopram, duloxetine, escitalopram, fluvoxamine, fluoxetine, milnacipran, levomilnacipran, paroxetine, sertraline, venlafaxine, desvenlafaxine, vilazodone, or vortioxetine at at least the minimum therapeutic dose for at least 4 weeks, and for no greater than 12 months, at screening. Modification of an effective preexisting therapy should not be made for the explicit purpose of entering a participant into the study 