BackgroundAdolescent childbirth continues as a public health concern, and investigation of postpartum posttraumatic stress symptoms (PTSS) and depression is important to inform future research and practice. Longitudinal studies exploring PTSS alone or in combination with depression are non-existent for postpartum adolescent populations. This study aimed to identify stress/PTSS and depression symptoms at 72 hours and three, six, and nine months postpartum, and determine if symptoms at each time point predicted later symptoms.MethodsA convenience sample of 303 adolescents 13–19 years of age were recruited from two postpartum units of one, large, public hospital. The Impact of Event Scale and the Edinburgh Postpartum Depression Inventory provided a screen of symptoms for stress/PTSS and depression at all time points. A lagged autoregressive model was developed to assess the predictive power of symptoms at each time point to the next across the extended postpartum period.ResultsAbout 30% of adolescents displayed early symptoms; 20% showed symptoms at the final time point. Early symptoms did not predict symptoms at 3 months; yet, symptoms at 3 months predicted symptoms at 6–9 months.LimitationsAttrition at final time points necessitated pooled data. Adolescents were primarily older, Hispanics, and recruited from one public hospital decreasing demographic representation. Use of screening tools prevented diagnostic outcomes. Unknown stressors occurring before and after pregnancy or birth may have influenced final outcomes.ConclusionsEarly symptoms were common and 3 month symptoms predicted later symptoms. For at risk adolescents, a plan for follow-up beyond hospital discharge is recommended.