Background: Although epidemiologic research consistently reports greater prevalence of major depressive disorder in women, small sample sizes in many studies do not allow for full elaboration of illness characteristics. This article examines sex differences in terms of illness attributes in a cohort of 2541 outpatients from across the United States who enrolled in the Sequenced Treatment Alternatives to Relieve Depression study.

Methods: Confirmatory analyses were performed in 2541 outpatients comparing men and women with regard to sociodemographic features, comorbid Axis I and Axis III conditions, and illness characteristics. Results were compared with those of our previous report on the initial population of the first 1500 individuals enrolled in Sequenced Treatment Alternatives to Relieve Depression study.

Results: In both samples, nearly two thirds of the sample (62.5%) were women. Women had greater symptom severity, but men had more episodes of major depression, despite no difference in the length of illness. No differences in age of onset emerged. As in the first cohort, women showed greater rates of an anxiety disorder, bulimia, and somatoform disorder, as well as more past suicide attempts, whereas men showed more alcohol and substance abuse. Women reported more appetite, weight, hypersomnia, interpersonal sensitivity, gastrointestinal and pain complaints, and less suicidal ideation. Irritability was equally common in men and women.

Conclusion: This large analysis confirmed most of the clinical features and comorbidities found to be more prevalent in the first cohort of women. In addition, this analysis corroborated previous research suggesting higher rates of atypical and anxious depression in women but refuted the notion of an "irritable depression" found in men. The report confirmed the 1.7:1 ratio for depression seen across sexes in the National Comorbidity Survey.