Prevalence and clinical features of atypical depression in depressed outpatients: a 467-case study.

The prevalence of DSM-IV atypical depression and differences between atypical versus non-atypical depression were investigated in 467 unipolar and bipolar depressed outpatients in private practice. Consecutive outpatients presenting for treatment of a major depressive episode were assessed with the Comprehensive Assessment of Symptoms and History following DSM-IV criteria, the Montgomery-Asberg Depression Rating Scale, and the Global Assessment of Functioning Scale. The prevalence of atypical depression was 38.1%. Of the variables investigated (unipolar and bipolar diagnoses, age at onset, gender, psychosis, comorbidity, chronicity, duration of illness, recurrences, and severity), age at onset was significantly lower, and female gender, comorbidity, and bipolar II disorder were significantly more common in atypical than nonatypical depression. Comparisons between bipolar II atypical depression and unipolar atypical depression did not show significant differences, apart from age at onset. Findings suggest that there are important clinical differences between atypical and non-atypical depression in private practice outpatients.