ssri meaning
Medical Definition of Selective serotonin reuptake inhibitor Selective serotonin reuptake inhibitor: A selective serotonin reuptake inhibitor (SSRI) is one of the commonly prescribed drugs for treating depression. SSRIs affect the chemicals that nerves in the brain use to send messages to one another. These chemical messengers, called neurotransmitters, are released by one nerve and taken up by other nerves.