What is the mechanism of action of SSRIs?

Selective serotonin reuptake inhibitors (SSRIs) primarily function by inhibiting the reuptake of serotonin in the brain's synapses. This action results in an increased availability of serotonin in the synaptic cleft, thereby enhancing neurotransmission related to mood regulation. The elevated levels of serotonin contribute to the antidepressant effects of SSRIs, making them effective in treating conditions such as major depressive disorder and anxiety disorders. By preventing serotonin from being reabsorbed into the presynaptic neuron, SSRIs help to prolong the action of serotonin in the brain, which is crucial for mood improvement and emotional balance.