SSRIs, or selective serotonin reuptake inhibitors, generally work by preventing the neurotransmitter serotonin from being re-absorbed by a neuron. That means the serotonin can stay in the synapse (space between neurons) longer, enabling signaling between neurons. A main difference among the SSRIs is how potently they block serotonin reuptake.
SSRIs also have slight differences in characteristics - such as how quickly they are eliminated from the body, side effects, and how they interact with other medications. Your doctor should work with you to help select the best SSRI for you to use in your individual circumstances.
-Liisa Hantsoo, Ph.D., May 28, 2020