Background: To find differences between early- and late-onset atypical depression (AD). Methods: 211 unipolar/bipolar II AD outpatients, interviewed with DSM-IV Structured Clinical Interview and depression rating scales. Logistic regression was used. Results: Early-onset AD was significantly associated with age, female gender, duration of illness, recurrences, chronicity, MADRS, bipolar II and unipolar. Early-onset bipolar II AD was significantly associated with age, female gender, duration of illness, recurrences and chronicity. Early-onset unipolar AD was significantly associated with age. Limitations: Age at onset recall bias, single interviewer, non-blind, cross-sectional assessment, bipolar II diagnosis reliability. Conclusions: Bipolar II AD is more likely to be chronic if early onset. (C) 2000 Elsevier Science B.V. All rights reserved.