Acute Stress Disorder is characterized by the development of severe anxiety, dissociative, and other symptoms that occurs within one month after exposure to an extreme traumatic stressor (e.g., witnessing a death or serious accident). As a response to the traumatic event, the individual develops dissociative symptoms. Individuals with Acute Stress Disorder have a decrease in emotional responsiveness, often finding it difficult or impossible to experience pleasure in previously enjoyable activities, and frequently feel guilty about pursuing usual life tasks.
A person with Acute Stress Disorder may experience difficulty concentrating, feel detached from their bodies, experience the world as unreal or dreamlike, or have increasing difficulty recalling specific details of the traumatic event (dissociative amnesia).
In addition, at least one symptom from each of the symptom clusters required for Post-traumatic Stress Disorder is present. First, the traumatic event is persistently re-experienced (e.g., recurrent recollections, images, thoughts, dreams, illusions, flashback episodes, a sense of reliving the event, or distress on exposure to reminders of the event). Second, reminders of the trauma (e.g., places, people, activities) are avoided. Finally, hyperarousal in response to stimuli reminiscent of the trauma is present (e.g., difficulty sleeping, irritability, poor concentration, hypervigilance, an exaggerated startle response, and motor restlessness).