Antidepressants increase risk of suicidal thinking and behavior in children, adolescents, and young adults (18-24 years of age) with major depressive disorder and other psychiatric disorders. Isocarboxazid is FDA approved for treatment of depression in children ≥16 years of age. May worsen psychosis or precipitate shift to mania or hypomania in bipolar disorder. Isocarboxazid is not FDA approved for treatment of bipolar depression. Hypertensive crisis might occur with foods/supplements high in tyramine, tryptophan, phenylalanine, or tyrosine content. May cause orthostatic hypotension (use with caution in cerebrovascular disease, cardiovascular disease, hypovolemia, or concurrent medication use which may predispose to hypotension/bradycardia). Use with caution in diabetes mellitus. Use with caution in glaucoma. Should not be used in history of liver disease or with abnormal liver function tests. Use with caution in renal impairment. Avoid use in severe impairment. Use with caution in risk of seizures, including patients with history of seizures, head trauma, brain damage, alcoholism, or concurrent therapy with medications which may lower seizure threshold. Use with caution in hyperthyroidism. Do not use with other MAOIs or antidepressants. Avoid products containing sympathomimetic stimulants, dextromethorphan, disulfiram, and meperidine. Concurrent use with antihypertensive agents may lead to exaggeration of hypotensive effects. Use with caution in hyperactive and/or hyperexcitable patients. May increase risks associated with electroconvulsive therapy. Isocarboxazid not indicated for initial therapy, but should be reserved for patients who have not responded to other antidepressants. Discontinue at least 48 hours prior to myelography.