# Monoamine Oxidase Inhibitor (MAOI) type of [[Antidepressant]] [Mayo Clinic](https://www.mayoclinic.org/diseases-conditions/depression/in-depth/maois/art-20043992) An enzyme called monoamine oxidase is involved in removing the neurotransmitters [[Norepinephrine]], [[serotonin]] and [[Dopamine]] from the brain. MAOIs prevent this from happening, which makes more of these brain chemicals available to effect changes in both cells and circuits that have been impacted by [[Depression]].