Postpartum Depression (PPD) is defined as depression that occurs after childbirth, with intense symptoms that last longer than baby blues. PPD differs greatly from baby blues, a term used to describe the typical sadness, worry and tiredness that women experience after childbirth, which often resolves within a week or two on its own. The symptoms of PPD interfere with many aspects of daily living and can have unhealthy short-term and long-term outcomes, both for the mother and baby. One-third of women in the U.S. with PPD are identified in clinical settings, yet only half of those begin psychotherapy treatment. Unfortunately, mothers whose newborns are in the Neonatal Intensive Care Unit (NICU) are at high risk for developing PPD, necessitating early identification and evidence-based treatment. Cognitive behavioral therapy (CBT) and interpersonal therapy (IPT) are the two most effective psychotherapy treatments for PPD, yet no randomized controlled clinical trials were found that directly compared the two types of treatment or determined whether combining the two approaches is more helpful for PPD than either approach alone. This clinical trial aims to compare the effectiveness of a 4-week intervention of either CBT or IPT for PPD in NICU mothers and to determine whether a sequential 8-week intervention (IPT then CBT, or CBT then IPT) is more beneficial.