The focus of this study is the role played by chronic dysregulation of affect in the presentation and treatment of severely abused and neglected children. The study used narrative story stems to assess children at a therapeutic residential school at two time points, two years apart. The method of analysis was the Child Attachment and Play Assessment (CAPA) which uses three constructs: attachment strategy, trauma and loss, and affect regulation. As well as demographic information, data were collected on DSM-V diagnoses and adverse childhood experiences (ACEs). The results lead to consideration of the importance of understanding the role of affect regulation in developmental trauma. Viewing the children’s difficulties in terms of chronic dysregulation of affect may be a more productive way of trying to understand children’s presenting problems than ACEs or psychiatric diagnoses. The findings have important implications for the medical model of child assessment using DSM-V diagnoses. A clinical implication of this research is that defences against such levels of early trauma need time and investment.