MAOI

What an MAOI actually is

MAOI stands for monoamine oxidase inhibitor. These were among the first antidepressants ever developed, dating back to the 1950s. Like other older classes, they can be effective, but they come with cautions that newer medications don’t, which is why you don’t see them prescribed as often today.

The name describes what they do. Monoamine oxidase is an enzyme in the body that breaks down certain chemical messengers in the brain. An MAOI blocks that enzyme, which leaves more of those messengers available.

How it works

The brain uses chemical messengers including serotonin, norepinephrine, and dopamine to send signals between nerve cells. The enzyme monoamine oxidase normally clears these messengers away. By slowing that enzyme down, an MAOI raises the levels of those messengers, which can lift mood over time.

The catch is that this same enzyme also helps break down a substance called tyramine, found in some foods. When an MAOI blocks the enzyme, tyramine can build up and push blood pressure dangerously high. That’s why people on MAOIs are given specific diet guidance.

What to know

Two cautions define this class. First, certain foods high in tyramine, such as aged cheeses, cured meats, and some fermented products, can cause a serious blood pressure spike. Second, MAOIs interact with many other medications, including some other antidepressants, certain pain medicines, and some cold remedies, which can lead to dangerous reactions.

Because of these cautions, MAOIs are usually a later choice, often considered when several other antidepressants haven’t worked. For the right person, under close supervision, they can be genuinely helpful. The diet and interaction rules are strict and specific, and they belong to the prescriber and pharmacist who set up the treatment, not to guesswork.

Related terms you’ll see next

• Antidepressant
• Tricyclic antidepressant
• SSRI
• Serotonin

When to seek professional care

If you’ve tried other antidepressants without enough benefit, ask a prescriber whether an MAOI might fit. Starting one means reviewing every medication and supplement you take and getting clear diet instructions. Never combine an MAOI with another medication without a prescriber’s sign-off, and never stop one suddenly. If you have a sudden severe headache, chest pain, or other alarming symptoms while taking one, treat it as an emergency.

<blockquote>
  <p><strong>MAOI:</strong> MAOI stands for monoamine oxidase inhibitor, one of the oldest classes of antidepressant. They can work well, but they require careful attention to diet and drug interactions, so they're usually reserved for when other treatments fail.</p>
  <p>&mdash; <a href="https://shrinktionary.com/terms/maoi/">Shrinktionary</a>, a plain-English mental health dictionary, medically reviewed by a board certified psychiatrist.</p>
</blockquote>