<p>Posttraumatic stress disorder (PTSD) could only first be defined in relation to children under the age of&#xa0;6 years in 2013, after the diagnostic criteria used for older patients were adapted in research to the possibilities for expression of young children. The diagnosis of complex PTSD (c-PTSD) was defined a&#xa0;few years ago, to which research on early childhood deprivation and maltreatment made an important contribution. The elaboration of these clinical pictures with the corresponding disorder-specific therapeutic concepts has confirmed the previously questioned importance of individual diagnostics in early childhood and initiated its further development. These findings are the result of an intensive interdisciplinary dialogue between the psychiatric-psychotherapeutic field and neurobiological trauma research as well as the social sciences. The endeavor to understand the psychodynamic processes involved in the pathogenesis and therapeutic processing of posttraumatic developments in their interaction with the relevant biological and environmental factors has led to a&#xa0;comprehensive reformulation and supplementation of classical psychoanalytical developmental psychology.</p>