Monoamine Oxidase Inhibitors

Monoamine oxidase inhibitors (MAOIs) were the first antidepressants to be discovered, and they remain potent medications utilized in treatment-resistant depression. Their discovery occurred serendipitously when iproniazid, a drug initially used to treat tuberculosis, was found to have antidepressant properties. This led to additional drug development, and from the 1950s to the 1970s, the MAOIs were the sole pharmacologic treatment for depression. However, with the emergence of tricyclic antidepressants (TCAs), and eventually selective serotonin reuptake inhibitors and serotonin-norepinepherine reuptake inhibitors, the MAOI class was relegated to a second- and now third-line role. The lowered priority is not due to lack of efficacy, as MAOIs are still the most efficacious pharmacologic treatment for atypical depression and social anxiety disorder. Instead, it is due to the stepwise improvement ...