Visit 1: 4 Months Post-Partum - Adult Attachment Interview (AAI). During this visit, each enrolled woman will participate in a modified version of the Adult Attachment Interview (AAI), a semi-structured 1½-2 hour-long interview involving specified questions and follow-up inquiries relating to childhood relationships with attachment figures. The attachment classifications will be revealed only to a third party group which will balance the order in which oxytocin or placebo is administered, based on attachment group. The investigators will also collect sociodemographic, breastfeeding data, and screening information for depression. The EPDS will be repeated during subsequent visits in order to calculate mean scores.