The first definition of AD as a preferentially monoamine oxidase inhibitor (MAOI)-responsive depression was introduced by West and Dally in 1959. Prior to such description, the term “atypical depression” was used in 1948 for describing depressed patients presenting with agitation, paranoid features, and perplexity, who responded well to electroconvulsive therapy (ECT). In DSM-III, the term was used for depression secondary to schizophrenia, for dysthymic disorder with long periods of well-being, and for brief depression (non-adjustment disorder).
In 1994, the DSM-IV introduced the criteria for “atypical features” as a modifier of major depression and dysthymia. Diagnosis of AD consists of criteria for depression in major depressive disorder (MDD), a major depressive episode of bipolar disorder, or dysthymia, together with the following specifiers of AD: significant mood reactivity (mood brightness in response to actual or potential positive events) and two or more of the following symptoms: significant weight gain, increase in appetite, hypersomnia, leaden paralysis, and a long-standing pattern of interpersonal rejection sensitivity that results in significant social or occupational impairment. In addition, the patient cannot meet the criteria for melancholic or catatonic depression. Surprisingly, no change in DSM-5 in 2013 was introduced, despite substantial remarks presented by some authors many years prior to the introduction of DSM-5.