Acute stress disorder (ASD) is characterized by acute stress reactions that may occur in the initial month after a person is exposed to a traumatic event. The disorder includes dissociative, reexperiencing, avoidance, and arousal symptoms. Some patients who experience ASD go on to experience posttraumatic stress disorder (PTSD), which is diagnosed only after four weeks following exposure to trauma.
Treatment for ASD, which is principally trauma-focused cognitive-behavioral therapy, is aimed at curtailing symptoms of acute stress responses and preventing their development into PTSD.
The epidemiology, pathogenesis, clinical manifestations, course, diagnosis, and treatment of ASD are described here. The treatment of ASD is discussed separately. The epidemiology, pathogenesis, clinical manifestations, course, diagnosis, and treatment of PTSD are also discussed separately. Dissociation associated with PTSD, and substance abuse associated with PTSD are also discussed separately. (See "Posttraumatic stress disorder: Epidemiology, pathophysiology, clinical manifestations, and diagnosis" and "Pharmacotherapy for posttraumatic stress disorder" and "Psychotherapy for posttraumatic stress disorder" and "Dissociative aspects of posttraumatic stress disorder: Epidemiology, clinical manifestations, and diagnosis" and "Co-occurring anxiety disorders and substance use disorders: Epidemiology, clinical manifestations, and diagnosis", section on 'Posttraumatic stress disorder'.)
Prevalence — The point prevalence of acute stress disorder (ASD) following trauma exposure has been estimated at between five and twenty percent, depending on the nature and severity of trauma and the instrument used to identify the disorder. Rates of ASD following specific types of trauma include:
- Motor vehicle accident: 13 percent , 21 percent 
- Mild traumatic brain injury: 14 percent 
- Assault: 16 percent , 19 percent 
- Burn: 10 percent 
- Industrial accident: 6 percent , 12 percent 
- Witnessing a mass shooting: 33 percent