What is "selective serotonin reuptake inhibitor"

n. (context pharmacology English) Any of a class of drugs, such as fluoxetine or sertraline, that inhibit the uptake of serotonin in the central nervous system and are often used to treat certain mental illnesses, such as depression.

' Selective serotonin re-uptake inhibitors' or serotonin-specific reuptake inhibitors (SSRIs) are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder and anxiety disorders.

The exact mechanism of SSRIs is unknown. SSRIs are believed to increase the extracellular level of the neurotransmitter serotonin by limiting its reabsorption into the presynaptic cell, increasing the level of serotonin in the synaptic cleft available to bind to the postsynaptic receptor. They have varying degrees of selectivity for the other monoamine transporters, with pure SSRIs having only weak affinity for the norepinephrine and dopamine transporters.

SSRIs are the most widely prescribed antidepressants in many countries. The efficacy of SSRIs in mild or moderate cases of depression has been disputed.