"The human response to psychological trauma is one of the most important public health problems in the world. Traumatic events confront people with such horror and threat that it may temporarily or permanently alter their capacity to cope, their biological threat perception, and their concepts of themselves. Traumatised individuals frequently develop post traumatic stress disorder (PTSD), a disorder in which the memory of the traumatic event comes to dominate the victims' consciousness, depleting their lives of meaning and pleasure. Recent developments in neuro-imaging and other fields of the neurosciences have highlighted the complex interrelationships between the psychological, psychiatric, biological, and neuroanatomical components of the disorder.
"The diagnosis of PTSD is characterised by three major elements:
• The repeated reliving of memories of the traumatic experience. These tend to involve intense sensory and visual memories of the event, which are often accompanied by extreme physiological and psychological distress.
• Avoidance of reminders of the trauma. Detatchment and emotional blunting coexist with intrusive recollections. This is associated with an inability to experience joy and pleasure, and with a general withdrawal from engagement with life.
• A pattern of increased arousal is the third element of PTSD. This is expressed by hypervigilance, irritability, memory and concentration problems, sleep disturbances, and an exaggerated startle response. Hyperarousal causes traumatized people to become easily distressed by unexpected stimuli. Their tendency to be triggered into reliving traumatic memories illustrates how their perceptions become excessively focused on the involuntary seeking out of the similarities between the present and their traumatic past. As a consequence, many neutral experiences become reinterpreted as being associated with the traumatic past."