Section Review: Central & Peripheral Nervous Systems: Selective serotonin reuptake inhibitors in the treatment of depression

Abstract

Selective serotonin reuptake inhibitors (SSRIs) comprise a relatively new class of antidepressants that are believed to act largely by blocking serotonin (5-HT) reuptake into presynaptic nerve terminals in the central nervous system. Widely prescribed throughout the world, SSRIs have a much more favourable side-effect profile than tricyclic antidepressants (TCAs) or monoamine oxidase inhibitors (MAOIs). Their efficacy vs. placebo has been well established and, in general, they exhibit comparable efficacy to tricyclic antidepressants. Controversy still exists as to whether the SSRIs are as efficacious as the TCAs in severe depression including melancholia. Differences do exist between the SSRIs in terms of their pharmacokinetic characteristics, inhibition of various hepatic cytochrome P₄₅₀ isoenzymes, and side-effect profile, though they are better tolerated than TCAs and MAOIs.