Given the incidence of encountering with traumatic life events and mental illnesses that are developing after trauma in the community, importance of the diagnosis of trauma-related disorders is emerging. Therefore, it is necessary to follow the changes in current diagnostic manuals. A number of diagnostic criteria have been changed with the publication of DSM-5 in May 2013. Specific diagnostic criteria have been defined for young children. While trauma-related diseases have been defined within anxiety disorders in DSM-IV, they are now being defined as a new individual set of diagnosis in DSM-V. The number of symptoms described in trauma related disorders was increased to 20 by the introduction of DSM 5. The number of symptom clusters defined for posttraumatic stress disorder (PTSD) has increased to four from three. The criteria of experiencing intense fear, anxiety and helplessness after the trauma and the acute and chronic markers (definitions) have been removed. Preschool and dissociative subtypes have been identified. In addition, unexpected loss of family members and relatives of the person due to natural causes have been removed from being a diagnostic criterion. Moreover, presence of at least one avoidance symptom has been set as a requirement for the diagnosis. All these changes in the diagnostic criteria are being estimated to reduce the rates of PTSD. On the other hand, it was noted that the redefined concept of PTSD by DSM- 5 have more overlap with complex PTSD diagnosis, which is a quite acceptable concept in trauma psychology.