Acute Stress Disorder

Between 5 and 20 percent of people exposed to a trauma such as a car accident, assault, or a mass shooting develop Acute Stress Disorder (ASD); and approximately half of these people go on to develop Post-Traumatic Stress Disorder. It is important to understand the potential physical and psychological effects that can occur after a traumatic event.

Although it shares many of the same symptoms as PTSD, ASD is a distinct diagnosis.
A person with ASD experiences psychological distress immediately following a traumatic event. Unlike PTSD, ASD is a temporary condition, and symptoms typically persist for at least 3 to 30 days after the traumatic event (commonly referred to as the acute phase).
If a person experiences symptoms for longer than a month, The ASD diagnosis would no longer apply and a clinician would assess them for PTSD.
According to the DSM-5, a patient is diagnosed with the disorder when he or she has nine or more symptoms.

Intrusion symptoms—involuntary and intrusive distressing memories of the trauma or recurrent distressing dreams
Negative mood symptoms—a persistent inability to experience positive emotions, such as happiness or love
Dissociative symptoms—time slowing, seeing oneself from an outsider's perspective, or being in a daze
Avoidance symptoms—avoidance of memories, thoughts, feelings, people, or places associated with the trauma
Arousal symptoms—difficulty falling or staying asleep, irritable behavior, or problems with concentration

Looks to change cognitions or patterns of thought surrounding the traumatic incident.
Works to alter behaviors in anxiety-provoking situations and attempts to prevent the development of post-traumatic stress disorder.