Monoamine oxidase inhibitors (MAOIs)

Monoamine oxidase inhibitors (MAOIs) are one of the oldest types of antidepressants still in use. Now that there are more alternatives available, MAOIs are not used as often as they used to be.

MAOIs can interact with a lot of other medications, which makes them hard to use alongside other medications. (You generally need to be off an MAOI for about 2 weeks before starting another antidepressant.) They can also trigger allergic reactions to certain foods, so being on them often involves dietary restrictions.

Still, MAOIs can be helpful if other types of antidepressants haven’t worked. They are sometimes used to treat bipolar disorder, or to treat neurological conditions such as Parkinson’s disease.

They can also be helpful with atypical depression, or “depression with atypical features.” In addition to the regular symptoms of depression, these “atypical features” are:

  • Weight gain or increased appetite
  • Sleeping too much
  • A sense of heaviness in the arms and legs (“leaden paralysis”)
  • Being extremely sensitive to social rejection

Other possible symptoms of atypical depression include:

  • Intensely craving attention
  • Panic attacks and anxiety
  • Increased sexual desire

Examples of MAOIs

Generic nameBrand name(s)

EMSAM is unique among MAOIs—and other antidepressants. Instead of a pill, it is taken as a skin patch. There is some evidence that it may be more effective and have fewer side effects than other MAOIs.

How do MAOIs work?

Like other mental health medications, MAOIs work by restoring the balance of the chemicals in your brain. These chemicals are called neurotransmitters. The main neurotransmitters affected by antidepressants are:

  • Serotonin, which affects your mood, energy level, appetite, and sleep
  • Dopamine, which affects motivation and pleasure—sometimes called the “feel good chemical”
  • Norepinephrine, which affects your energy level, focus and attention. Related to adrenaline and has similar effects

Most antidepressants mainly boost serotonin levels. MAOIs boost all three. In fact, MAOIs helped scientists discover how these chemicals are involved in depression in the first place.

Side effects of MAOIs


  • Dizziness and fainting
  • Drowsiness, or trouble sleeping
  • Nausea

Less Common:

  • Weight gain
  • Muscle cramps or involuntary muscle jerks
  • Reduced sexual desire or difficulty reaching orgasm
  • Increased blood pressure
  • Prickling or tingling sensation in the skin (paresthesia)
  • Serotonin syndrome

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