What is the mechanism of action of SSRIs?

The mechanism of action of selective serotonin reuptake inhibitors (SSRIs) is primarily the inhibition of serotonin reuptake. SSRIs, such as fluoxetine, sertraline, and escitalopram, work by blocking the serotonin transporter (SERT), which leads to increased levels of serotonin in the synaptic cleft. This increased serotonin availability enhances neurotransmission at serotonin receptors, contributing to their antidepressant effects.

Understanding the importance of serotonin in mood regulation illuminates why SSRIs are effective for conditions like depression and anxiety disorders. By preventing its reuptake, SSRIs facilitate a prolonged action of serotonin, which is crucial for mood stabilization. This is fundamental in pharmacologic treatment paradigms involving mental health disorders.

Other mechanisms mentioned in the alternatives, such as dopamine reuptake inhibition and norepinephrine enhancement, do not apply to SSRIs, as these would pertain to different classes of antidepressants, such as atypical antidepressants or norepinephrine-dopamine reuptake inhibitors. Additionally, SSRIs do not stimulate serotonin receptors directly; their primary role is to increase serotonin availability rather than activate the receptors.