• Hamilton Depression Rating Scale (HAM-D) [ Time Frame: Measured at baseline; Weeks 4, 8, and 12 of treatment; and Months 3 and 6 of follow-up ] [ Designated as safety issue: No ]
  

• Depression illness severity based on Beck Depression Inventory (BDI) and Edinburgh Postnatal Depression Scale (EPDS) [ Time Frame: Measured at baseline; Weeks 4, 8, and 12 of treatment; and Months 3 and 6 of follow-up ] [ Designated as safety issue: No ]
  
• General illness severity based on Clinical Global Impression (CGI) scale [ Time Frame: Measured at baseline; Weeks 4, 8, and 12 of treatment; and Months 3 and 6 of follow-up ] [ Designated as safety issue: No ]
  
• Social functioning based on Postpartum Adjustment Questionnaire (PPAQ) [ Time Frame: Measured at baseline; Weeks 4, 8, and 12 of treatment; and Months 3 and 6 of follow-up ] [ Designated as safety issue: No ]
  
• Anxiety based on Beck Anxiety Inventory (BAI) [ Time Frame: Measured at baseline; Weeks 4, 8, and 12 of treatment; and Months 3 and 6 of follow-up ] [ Designated as safety issue: No ]
  

Postpartum depression (PPD) occurs in approximately 13% of postpartum women. The impact of PPD is significant, including emotional distress for the woman as well as disturbances in infant development. Common signs of depression after childbirth may include anxiety, irritability, low energy, and lack of concern for self or infant. If left untreated, PPD may last for more than 1 year, causing strain on family life and the mother's relationship with her infant. Infants of depressed mothers are also at a higher risk for developmental delays, behavioral problems, and difficulty eating and sleeping. Despite the public health significance of PPD, relatively little research has been done to determine the most effective treatments. Specifically, there is a lack of research concerning the use of antidepressant medication for treating PPD. Interpersonal psychotherapy (IPT), which focuses on interpersonal issues related to depression, has been more thoroughly studied for the treatment for PPD, but it has not been compared to the other treatment. This study will evaluate the effectiveness of antidepressant medication alone and IPT alone in treating women with PPD.

Participation in this double-blind study will last 9 months. Participants will first undergo initial assessments, which include interviews about depressive symptoms, self-report forms about medical history, blood tests, and a pregnancy test. Participants will then be randomly assigned to one of three treatments: sertraline, placebo, or IPT. All three treatments will be administered over 12 weeks. Participants assigned to take sertraline or placebo will attend eight 30-minute sessions over the 12-week treatment period. During these sessions, participants will be administered the study medication and will be assisted with parenting issues and skills by a psychiatrist. Participants receiving IPT will attend weekly 45-minute sessions over the 12-week treatment period. These sessions will focus on improving relationships with others, setting goals, and increasing coping skills. All participants will also complete interviews and questionnaires about their depression once a month. Following the 12 weeks of treatment, participants will undergo follow-up visits occurring at Weeks 1 or 2 and Months 3 and 6 post-treatment. Follow-up assessments will repeat initial interviews and questionnaires and will include a form about the infant's nature.