MAOIs inhibit the activity of monoamine oxidase, an enzyme responsible for breaking down neurotransmitters such as serotonin, dopamine, and norepinephrine. By inhibiting this enzyme, MAOIs increase the levels of these neurotransmitters in the brain. Common MAOIs include Phenelzine, Tranylcypromine, and Isocarboxazid. They are typically prescribed for severe depression that has not responded to other treatments.
