"prozac, zoloft, paxil, and celexa are some of the more widely used "

Prozac (fluoxetine), Zoloft (sertraline), Paxil (paroxetine), and Celexa (citalopram) are all drugs used as anti-depressants.

They are all marketed as Selective Serotonin Reuptake Inhibitors (SSRIs).

The above drugs are SSRIs, which was the first kind of rationally designed psychotropic medications. These drugs are efficacious and act by affecting only a specific neural site.