IntroductionThis study briefly reviews complex trauma and discusses how it manifests in adolescents with a history of abuse and neglect during childhood. A history of childhood abuse and neglect often leads to long-term emotional, behavioral, and physical dysregulation that does not always meet diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR). American Psychiatric Association for post-traumatic stress disorder (PTSD). ). This has led to the proposal of a separate but related diagnosis called traumatic developmental disorder (Cook, Blaustein, Spinazzola, & van der Kolk, 2003; van der Kolk, 2005; Najjar, Weller, Weisbrot, & Weller, 2008). This diagnosis is based on an evaluation of the literature on complex trauma and its long-term consequences on mental and physical health. In this study, we will examine the following: 1) the scope of complex trauma in terms of its general impact on individuals and society; 2) a description of the phenomenology of complex trauma; 3) the developmental impact of complex trauma on adolescents; and 4) the diagnosis, treatment and prevention of complex trauma in adolescents. Complex trauma refers to both exposures and the developmental impact of long-term exposure to traumatic events during childhood and adolescence. Traumatic exposures are typically interpersonal in nature, including childhood physical, sexual, and emotional abuse and neglect. Traumatic exposures may also include repeated surgeries, chemotherapy, or other adverse events during childhood. Complex trauma has a significant impact on development across the lifespan. In a large epidemiological survey, the Adverse Childhood Experiences (ACE) study, conducted among more than 17,000 adults in the general population...... middle of article.... ..icine, 14, 245 -258.Gabowitz, D., Zucker, M. and Cook, A. (2008) Neuropsychological assessment in clinical assessment of children and adolescents with complex trauma. Journal of Child and Adolescent Trauma, 1, 163-178. Najjar, F., Weller, RA Weisbrot, J. and Weller, EB (2008). Posttraumatic stress disorder and treatment in children and adolescents. Current Psychiatry Reports, 40, 104-108. Perrin, S., Smith, P. and Yule, W. (2000). Practitioner review: The assessment and treatment of posttraumatic stress disorder in children and adolescents. Journal of Child Psychology and Psychiatry, 41, 227-280. Van der Kolk, BA (2005). Traumatic developmental disorder. Psychiatric Times, 35, 401-408. Weiss, D., S. (2004). The Event Impact Scale – Revised. In JP Wilson & TM Keane (Eds.), Assessment of psychological trauma and PTSD. New York: Guilford.