Which medication is classified as a serotonin reuptake inhibitor?

Citalopram is classified as a selective serotonin reuptake inhibitor (SSRI). This class of medications is primarily used to treat depression and anxiety by increasing the levels of serotonin in the brain. Serotonin is a neurotransmitter that plays a crucial role in mood regulation. By inhibiting the reuptake of serotonin, citalopram ensures that more serotonin remains available in the synaptic cleft, thereby enhancing serotonin signaling and improving mood.

The other options, while also used to treat mood disorders, do not fall under the category of SSRIs. Amitriptyline and nortriptyline are tricyclic antidepressants, which work on various neurotransmitters but are not specialized in serotonin reuptake inhibition the way SSRIs are. Trazodone, although it affects serotonin levels, is primarily classified as a serotonin antagonist and reuptake inhibitor (SARI), which combines features of both SSRIs and other mechanisms. Thus, citalopram stands out as the medication that specifically belongs to the SSRI class.