This dissertation is a mixed methods analysis investigating postpartum depression as it is experienced by self-reported depressed Mexican American adolescent and adult mothers. The qualitative portion of this study explores pregnancy and motherhood to better understand meanings attached to depression. Six adolescent and six adult mothers, were recruited from the Dallas/Fort-Worth area. Each was interviewed twice, using semi-structured interview guides. The quantitative phase utilizes a national sample of self-reported depressed Hispanic mothers to identify breastfeeding behavior and mothers' perceptions of the physical health of their babies. Specifically, a secondary analysis of the National Survey of Children's Health, 2003 was used to supplement the qualitative data. This study provides a theoretical framework of fragmented identity to explain socio-cultural factors contributing to postpartum depression among Mexican American adolescent and adult mothers. Common themes leading to a fragmented identify were indentified. Contributors to postpartum depression include: unplanned pregnancy, internal struggle between cultures, body image and family conflict. Stigma associated with teen motherhood also contributed to depression among adolescent mothers while the medicalization of childbirth was a contributing factor of depression among the adult mothers. Additionally, the duration of breastfeeding and mothers' perceptions of their babies' physical health were impacted by depression, but breastfeeding initiation was not.