This article describes the nature of postpartum psychosis (PP), a group of disorders belonging to the bipolar spectrum that share the common features of the presence of psychosis & onset of symptoms during the postpartum period. The author discusses the prognosis of the illness, with special focus on its increased risk of suicide & infanticide. Current best practices in the prevention, clinical management, & acute & long-term treatment of PP are reviewed, & complicating factors are briefly discussed. (46 refs)