The effects of childhood abuse are diverse, and although pathology is not the only outcome, psychiatric illness, including posttraumatic stress disorder (PTSD), can develop. However, adult PTSD is less common among those who experienced single-event traumas as children than it is among those who experienced childhood abuse. In addition, PTSD is more common among adults than children who experienced childhood abuse. Such evidence raises doubt about the direct, causal link between childhood trauma and adult PTSD. The experience of childhood trauma, and in particular abuse, has been identified as a risk factor for subsequent development of PTSD following exposure to adult trauma, and a substantial literature identifies revictimization as a factor that plays a pivotal role in this trajectory. The literature on the developmental effects of childhood abuse and pathways to revictimization, when considered in tandem with the biological effects of early stress in animal models, may provide some explanations for this. Specifically, it seems possible that permanent sensitization of the hypothalamic–pituitary–adrenal axis and behavioral outcomes are a consequence of childhood abuse, and these combine with the impact of retraumatization to sustain, perpetuate, and amplify symptomatology of those exposed to maltreatment in childhood.