Depression is a common and serious health problem that occurs twice as often in women as in men. The lifetime prevalence of major depression in women is estimated to be as high as 21%. Although less severe and less common, mild depression and dysthymia (chronic mild depression) can cause functional disability and require treatment. Regardless of severity or duration, depression can be difficult to recognize because it frequently is masked by complaints that accompany other common obstetric and gynecologic illnesses and events. This article reviews the various depressive disorders in women with a focus on presentations that occur in obstetric and gynecologic practice.