[Post-traumatic stress: the mechanisms of trauma]

Since the first description of stress syndrome, by Hans Selye in 1936, much has been investigated concerning the etiological mechanisms of stress. In recent years the intense research in the field of the neurobiology of stress, namely in Post-Traumatic Stress Disorder (PTSD), revealed some of the mechanisms and neurological structures involved with stress. A systematic research of literature published until December of 2006 was made, through the MEDLINE using as keywords neurobiology, stress, post traumatic stress disorder, neuroendocrine, neurochemical, neuroimmunological, neuroimaging. Of a total of 70 found articles, 39 were selected by its adequacy and acquired for the accomplishment of this revision. Also, reference books were consulted for the areas of theoretical concepts of stress and phenomenology of trauma. The authors intend to review the way cerebral structures, multiple neuronal and hormonal ways form a complex mechanism of reaction to stress. It is intended with this article to demonstrate the relation between psychopathological events, namely in PTSD, the phenomenology of the trauma and neurobiological changes.