Unlike most psychiatric disorders both Acute Stress Disorder and Post-Traumatic Stress Disorder are triggered by a specific event. Acute Stress Disorder refers to a reaction occurring within 4 weeks and lasting from 2 days to 4 weeks after an individual was exposed to a trauma. The person responded with intense fear, helplessness or horror to an event or events that involved actual or threatened death or serious injury, or a threat to the one’s physical integrity. Examples are rape, mugging, combat, natural disasters, etc. Acute stress disorder is a diagnostic category introduced in 1994 to differentiate time-limited reactions to trauma from post-traumatic stress disorder (PTSD). Not all individuals exposed to trauma will experience a disorder. The impact of a traumatic event on a child, depends on the severity of the event and the child’s previous level of functioning.