The essential feature of post-traumatic stress disorder (PTSD) is the development of symptoms following exposure to one or more traumatic events. The presentation of PTSD varies. In some individuals, fear-based reexperiencing, emotional, and behavioral symptoms may predominate. Anhedonic (reduced ability to experience pleasure) or dysphoric mood states and negative thoughts may be most prominent in others. Of course, some individuals experience combinations of these symptom patterns.
A traumatic event that qualifies for a diagnosis includes actual or threatened death, serious injury, or sexual violence. This can be through directly experiencing the traumatic event, witnessing the event occur, learning that the event happened to a family member or friend, or indirect exposure during occupational duties.
The disorder may be especially severe or long-lasting when the stressor is interpersonal and intentional (e.g., torture, sexual violence).