Post traumatic stress disorder (PTSD) is long-term psychological trauma following a life-threatening incident, the degree of which seems to be independent of the extent of physical injury. It can be a natural disasters, disastrous events or accidents, bombing, torture or death camps. Whilst the later distress is triggered by the incident, it may be delayed for months or years. It produces a wide range of symptoms in men and women who have experienced a traumatic event that provoked intense fear, helplessness or horror. The events are sometimes re-experienced later through intrusive memories, nightmares, hallucinations or flashbacks, usually triggered by anything that symbolizes or resembles the trauma. Troubled sleep, irritability, anger, poor concentration, hypervigilance and exaggerated responses are often symptoms. Individuals may feel depression, detachment or estrangement, guilt, intense anxiety and panic and other negative emotions. The person may also tries to avoid thoughts or feelings about the trauma and may even lose the ability to recall some important aspects of it.
The early pattern of distress that points to long-term problems is poorly known. This means PTSD is often under-diagnosed or missed in a medical or surgical outpatient setting, or crisis relief station. Probable early signals of PTSD are depression; recurring memories or flashbacks of the event; patterns of agitation and anxiety, or disordered arousal, such as difficulty falling or staying asleep, panic attacks, irritability or outbursts of anger or hypervigilance; and the extent of disassociation (a psychological method of coping) during the accident. Also common is that soon after the traumatic event the person starts suffering from "emotional anaesthesia"—decreased ability to have affectionate feelings towards others.
Generally, only 15% of trauma victims suffer longterm PTSD symptoms. Research conducted in Australia found that twenty percent of people involved in traumatic accidents develop PTSD. Three years after suffering a traumatic injury, 19% of 551 adults were worse off psychologically. Of a group of 24 patients involved in serious motor accidents, nine were found to have PTSD to varying degrees one month after the accident; however, when followed up six months later none had been officially diagnosed or received treatment by medical authorities.
In South Africa in 1993 violence has become an integral part of every day life due to the plethora of political killings, revenge slayings and murder by criminals. A form of continuous traumatic stress has been described.
Humanitarian agencies report many new cases of cancer, multiple sclerosis and diabetes in Bosnia, which were possibly provoked by the trauma of war. Nearly one third of the population are judges to be suffering from post-traumatic stress disorder.
A study showed that Vietnam veterans and survivors of childhood abuse with PTSD performed 40% worse on verbal memory tests than veterans of the same age and educational background who did not suffer the disorder. There is however no deficiency in overall IQ scores or in other kinds of memory.