Selective Serotonin Reuptake Inhibitor (SSRI)
A selective serotonin reuptake inhibitor (SSRI) is a type of antidepressant drug that blocks or slows the removal of serotonin from synapses, preventing it from being absorbed by nerve cells that make it. Serotonin is a neurotransmitter thought to be responsible for many functions including appetite and mood. By blocking the uptake of serotonin, SSRIs can help regulate mood.