selective serotonin reuptake inhibitor selective serotonin reuptake inhibitor selective serotonin reuptake inhibitors (ssris) are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder, anxiety disorders, and other psychological conditions. selective serotonin reuptake inhibitordrug classserotonin, the neurotransmitter that is involved in the mechanism of action of ssris.class identifierssynonymsserotonin-specific reuptake inhibitors, serotonergic antidepressantsusemajor depressive disorder, anxiety disordersatc coden06abbiological targetserotonin transporterclinical datadrugs.comdrug classesconsumer reportsbest buy drugs