Few longitudinal studies have analyzed how traumatic experiences (e.g. home removal, violence exposure) influence both depressive and Post-Traumatic Stress (PTS) symptoms in children involved with Child Protective Services (CPS). This study investigated the change trajectories of both depressive and PTS symptomatology as well as their associations over time, focusing on the effect of complex trauma. Data were obtained from the National Survey of Child and Adolescent Well-Being (1999textendash 2007), a nationally representative study of children and adolescents who were referred to child protective services for alleged maltreatment. The Children’s Depression Inventory (CDI) scale measured depressive symptoms and the Post Traumatic Stress Disorder section of a version of the Trauma Symptom Checklist for Children (TSCC) provided the measure of current traumarelated symptoms or distress. Analyses were conducted using a parallel process growth curve model. The participants' initial levels of depressive and PTS symptomatology were significantly and positively related; furthermore, any changes in these two outcomes were also correlated longitudinally. The initial assessment of PTS symptoms significantly contributed to the advancement of more severe depressive symptoms over time. No significant differences were found between youth who remained in the home and those removed from the home. However, violence exposure, sexual abuse, gender and age were significant predictors of level and rate of change in both PTS and depressive symptoms. PTS growth factors mediated the longitudinal relationship between witnessing severe violence and depressive symptoms. The findings suggest a complex developmental association between depressive and PTS symptomatology among CPS-involved youth that is rooted in early childhood experiences with complex trauma.