what is monoamine oxidase inhibitor
MAOIs were the first type of antidepressant developed, and became widely used in the 1950s. A monoamine oxidase inhibitor, or MAOI, is a type of antidepressant drug. MAOIs balance the level of certain chemicals in the brain by inhibiting the enzyme known as monoamine oxidase. MAOIs were the first type of antidepressant developed, and became widely used in the 1950s. A monoamine oxidase inhibitor, or MAOI, is a type of antidepressant drug. In addition to treating depression, MAOIs are sometimes used to treat such conditions as: 1  Bipolar disorder.  Panic disorder.