Partial validation of the atypical features subtype of major depressive disorder

Background: Symptoms of the atypical features subtype of major depressive disorder include mood reactivity, hypersomnia, hyperphagia, leaden paralysis, and rejection sensitivity. This subtype was introduced into the mood disorders section of the DSM-IV following a series of antidepressant trials showing that such patients responded preferentially to monoamine oxidase inhibitors. Studies aimed at validating the atypical features subtype have yielded inconsistent results. Our study sought to reevaluate the validity of atypical depression by examining the demographic and clinical features of a large cohort of depressed patients who met DSM-IV criteria for atypical features. Methods: We evaluated 579 psychiatric outpatients with a current diagnosis of major depressive disorder for the presence of atypical features. Detailed demographic and clinical information was obtained for each patient through semistructured interviews. Using the available literature, we made a series of a priori hypotheses regarding how depressed patients with atypical features (n= 130) would differ from those without atypical features (n=449). In addition, we tested the strength of the associations between each Of the 5 atypical symptoms. Results: Although many of the predicted hypotheses were substantiated, an equal number were not. Correlation analyses revealed modest associations between several of the atypical symptoms, but mood reactivity was not associated with any of the other symptom criteria. Conclusion: Our results provide partial support for the validity of the atypical features subtype of major depressive disorder.