 PPD is similar to major depression, but develops around the time a woman gives birth. Women with PPD often suffer serious physical and emotional impairments. Controversy exists regarding the role of hormone changes in postpartum depression. This study will examine the role of hormone changes in three groups of women: those who recently gave birth and have mild to moderately severe PDD Group 1, women who recently gave birth and do not have PDD Group 2, and those who are currently pregnant and experienced an episode of PDD with a previous birth Group 3. 