 Controversy exists regarding the relevance of changes in gonadal steroids for postpartum-onset depressions. The purpose of this protocol is to allow for the careful screening of patients and healthy volunteers for participation in research protocols that examine the role of gonadal steroids in postpartum-onset depressions PPD and for the collection of natural history data. Women in this protocol will undergo an evaluation which may include: a psychiatric interview; a diagnostic interview; rating scales; a medical history; a physical exam; blood and urine laboratory evaluation; and a request for medical records. The data collected may also be linked with data from other PPD protocols e.g., DNA, psychophysiology tests, treatment studies, etc. for the purposes of better understanding the diagnosis, pathophysiology, and treatment response of women with PPD. Upon conclusion of the screening process, subjects will either be offered participation in a research protocol and will sign the appropriate informed consent, or will be considered not appropriate for participation in research and will be referred back into the community. The second purpose of this protocol is to permit the identification of pregnant women who are at risk for developing postpartum depression PPD, and who are followed longitudinally through the postpartum in an effort to confirm the association of depression onset with change in reproductive endocrine function. This protocol, then, serves as a screening and evaluation protocol to recruit subjects who are characterized with standard measures in this protocol and then offered participation in related studies. 