Post-traumatic stress disorder or PTSD is a mental illness caused by severe physical or mental trauma that is typical of military service in a war zone, continued sexual abuse, or severe physical injury typical of natural disasters or structural collapse. Before it was identified as a mental disorder, it often went by the name of battle fatigue or shell shock.
PTSD sufferers have increased awareness, often causing them to lose emotional control in any stressful situation, and to be over-vigilant at almost all times. They almost always have difficulty sleeping due to dreams that cause them to re-live their traumatic experiences.
Treatment is difficult and often unsuccessful. Psychotherapy, although it gives relief in many cases, often results in the patient dwelling more over the experience, increasing their anxiety. Moreover, anti-anxiety medications, although they lessen the symptoms, have adverse side effects and do nothing for the underlying condition. Most patients have extreme difficulty dealing with normal social situations and often find themselves either homeless, isolated, or institutionalized.