This could be any event perceived as life threatening. These include accidents, rapes, muggings, combat and natural disasters.

The therapeutic significance of the diagnosis is its capacity to predict, fairly accurately, the potential for the more chronic condition of Posttraumatic Stress Disorder (PTSD).

With this diagnostic tool vulnerable individuals are able to receive appropriate therapeutic assistance more immediately thereby improving the chances of a more favorable prognosis.

Symptoms of Acute stress disorder appear at the time of the traumatic event or shortly after. The dominant theme is the state of dissociation in its various forms. This detachment of the mind from the emotional state, or even the body, is a critical feature of the illness.

The Library of the National Medical Society lists these primary symptoms:

1. The subjective sense of numbing detachment. An absence of emotional responsiveness.
2. A reduction of awareness.
3. Derealization.
4. Depersonalization.

The above symptoms are coupled with other secondary problems like a heightened generalized anxiety -- a kind of hyper-vigilance that exhausts the sufferer.

These symptoms must be apparent for at least two days to a maximum of four weeks, all within the first month following the traumatic event. If the symptoms persist beyond this time period the diagnosis will be changed to that of the more chronic PTSD.

Individuals diagnosed with Acute Stress Disorder suffer the persistent re-experience of the traumatic event in the shape of dreams and flashbacks that can occur at any time without warning. These intrusive recollections, together with the persistent avoidance of situations or stimuli that are reminders of the event, place unbearable restrictions on the functioning of the sufferer.