The term atypical depression generally indicates either depression accompanied by severe anxiety (type A) or by atypical vegetative symptoms, ie, increased appetite, weight, sleep, or libido (type V). Early age at onset, predominance in women, outpatient status, mild intensity, rarity of attempted suicide, nonbipolarity, nonendogenicity, and minimal psychomotor change are common to both types. Some types of bipolar depression may be considered as atypical if accompanied by reversed vegetative change. Monoamine oxidase inhibitors are more effective than placebo in treating atypical depression, but their reported superiority to tricyclic antidepressants awaits confirmation, for which the development of appropriate operational criteria would be helpful. Atypical depression is a term that covers several types of depressive disorder and can, for the most part, be better defined using the standard nomenclature.