How does Monoamine oxidase inhibitors (MAOIs) work?
Once the brain’s three neurotransmitters, known as monoamines (serotonin, norepinephrine, and dopamine), have played their part in sending messages in the brain, they get burned up by a protein in the brain called monoamine oxidase, a liver and brain enzyme. Antidepressants known as monoamine oxidase inhibitors work by blocking this cleanup activity. When the excess neurotransmitters don’t get destroyed, they start piling up in the brain. And since depression is associated with low levels of these monoamines, it’s not surprising that increasing the monoamines ease depressive symptoms.