Defining the boundaries of atypical depression.

Psychopharacologist have had a longstanding interest in identifying a depressive subtype which selectively benefits from monoamine oxidase inhibitors (MAOIs). A superior rate of improvement with MAOI treatment might help delineate a depressive subgroup with pathophysiology different from other depressive syndromes. Research is described which indicates that patients with reactivity of mood, as well as two of four associated features (hypersomnia, overeating, lethargy, and rejection sensitivity), may have a preferential response to phenelzine as compared with imipramine or placebo. Preliminary data are presented to suggest that patients with reactive mood and only one associated feature may have a preferential response rate to phenelzine compared to imipramine and placebo. Data on patients with reactive mood but no associated features are insufficient at this point to draw any conclusions.