Monoamine Oxidase (MAO) is an enzyme found in the body that plays a crucial role in breaking down neurotransmitters, which are chemicals that transmit signals in the brain. It primarily targets monoamines, such as serotonin, dopamine, and norepinephrine, helping to regulate mood, emotions, and various bodily functions. There are two main types of MAO: MAO-A and MAO-B. MAO-A primarily breaks down serotonin and norepinephrine, while MAO-B mainly targets dopamine. Inhibitors of these enzymes, known as MAO inhibitors, are used in the treatment of certain mental health conditions, including depression and anxiety, by increasing the levels of these neurotransmitters in the brain.