The Pregnancy Depression Scale (PDS): a screening tool for depression in pregnancy.

Depression in pregnancy can be underdiagnosed as a consequence of the symptoms being misattributed to "normal pregnancy." There are currently no validated clinician-rated scales that assess for depression specifically during pregnancy. We sought to develop a brief, convenient screening tool to identify depression in pregnant women in the community setting. Prospective mood data using the 28-item Hamilton Depression Rating Scale (HDRS) were collected monthly in 196 pregnant women with a history of a major depressive disorder. These data were analyzed to delineate those HDRS items associated (elevated) with normal pregnancy vs. those indicative of a pregnant woman meeting diagnostic criteria for a major depressive episode. Endorsement of symptoms on seven items of the HDRS were highly predictive of having a major depressive episode during pregnancy. We present a well-validated, brief scale to screen pregnant women for clinical depression. Whether this study will generalize to women who do not have a history of major depression remains to be studied.