Objective: To determine the incidence, clinical and demographic correlates, and relationship to treatment outcome of self-reported premenstrual exacerbation of depressive symptoms in premenopausal women with major depressive disorder who are receiving antidepressant medication. Method: This post-hoc analysis used clinical trial data from treatment-seeking, premenopausal, adult female outpatients with major depression who were not using hormonal contraceptives. For this report, citalopram was used as the first treatment step. We also used data from the second step in which one of three new medications were used (bupropion-SR [sustained release], venlafaxine-XR [extended release], or sertraline). Treatmentblinded assessors obtained baseline treatment outcomes data. We hypothesized that those with reported premenstrual depressive symptom exacerbation would have more general medical conditions, longer index depressive episodes, lower response or remission rates, and shorter times-to-relapse with citalopram, and that they would have a better outcome with sertraline than with bupropion-SR. Results: At baseline, 66% (n = 545/821) of women reported premenstrual exacerbation. They had more general medical conditions, more anxious features, longer index episodes, and shorter times-to-relapse (41.3 to 47