Complex posttraumatic stress disorder (CPTSD) is a diagnostic entity that will be included in the forth-coming edition of the International Classification of Diseases, 11th Revision (ICD-11). It denotes a severe form of PTSD, comprising not only the symptom clusters of PTSD (Diagnostic and Statistical Manual of Mental Disorders,Fourth Edition [DSM-IV-TR]), but also clusters reflecting difficulties in regulating emotions, disturbances in relational capacities, and adversely affected belief systems about oneself, others, or the world.