Primary objectives: Remission of Major Depression: To determine the efficacy of a flexibly titrated dose of Escitalopram (10mg to 20 mg) in the treatment of women with postpartum depression. The primary outcome measure will be remission of major depression, defined as a score of 12 or less on the Montgomery-Asberg Depression Scale. A score of 7 or less on the Hamilton Depression Scale (21 item) will be used as a secondary measure of remission. The null hypothesis is that flexibly dosed Escitalopram does not lead to remission of major depression based on total MADRS scores after 8 weeks of treatment.