It may help to explain what PTSD is.

Without wanting to go into too much detail, PTSD is a diagnosis of anxiety, hyper-arousal or depression brought about by either an overwhelming traumatic event, (rape, severe crashes, bereavement, etc.), or by longer periods of trauma, (such as childhood sexual abuse or neglect).
To simplify issues, this page will deal with the first of these; one-off traumas. We will discuss these as PTSD.
Longer term traumas, and one-off traumas when experienced by people who have suffered significant traumas in the past, give rise to deeper forms of traumatic affect. These are termed Complex PTSD, and please go here for our page on C-PTSD.

In the face of such traumas, most people will experience ongoing effects, naturally, and this seems to be a way of the mind recovering from the effect of the trauma. This will drop off in time, and gradually many people will stop suffering. The body has naturally processed the trauma, recovering organically and naturally.

A significant minority, though, will continue to suffer from symptoms as a result of the trauma, and the amount of suffering will be effected by the amount of trauma in the first place, their ability to find support, how young they were when the trauma happened, and how well they process stress related to their personal history and possibly genetic influences.

This is termed Post-Traumatic Stress Disorder, or PTSD.

* Peter Levine, renowned trauma therapist, has proposed that PTSD be replaced bu PTSI - Post-traumatic Stress Injury, ie. a temporarily unresolved coping state. We agree.