MonoAmine Oxidase Inhibitors or MAOIs are a class of pharmaceutical used in the treatment of clinical depression and many other forms of mental illness. They are particularly effective in atypical cases. However, because of the high risk of drug interactions, they are usually saved as a drug of last resort when other anti-depressants are ineffective.
Like many other anti-depressants, MAOIs work by indirectly affecting neurotransmitters, in this case, serotonin, melatonin, adrenaline and norepinephrine.
However, the same chemical reaction that give MAOIs a therapeutic effect also affects how the body processes many nutrients, including those in cheese and poultry. Patients taking MAOIs must avoid yeast and meat extracts entirely. MAOIs also interact with many other pharmaceuticals, including stimulants.
MAOIs also result in physical dependence and withdrawal can be a problem. If the drug must be discontinued, it has to be done over a period of several weeks with progressively lower doses.