Posttraumatic Stress Disorder

This article reviews concepts that help synthesize the data on posttraumatic stress disorder(PTSD), a very complex condition in terms of its etiology, psychobiology, epidemiology, comorbidity,and treatment. At least four neurobiologic systems are involved in PTSD: the catecholamine, thehypothalamic-pituitary-adrenocortical, the thyroid, and the endogenous opioid systems. Six other systemsare probably or possibly implicated as well. The avoidance and hyperarousal of PTSD distort thepatient’s appraisal of the world. The symptoms of PTSD can be understood through models of learningand memory, which form the basis of behavioral treatments. The concepts of tonic and phasic alterationand of allostasis versus homeostasis also shed light on PTSD. In addition to PTSD, there maybe other identifiable posttraumatic syndromes that might be diagnosed separately, such as "complex"PTSD. Cross-cultural issues may also affect clinical phenomenology and thereby confuse the diagnosis.Comorbid disorders may actually be clues to subtypes of PTSD. The fact that victims of PTSD arealso more vulnerable to medical illnesses makes a closer relationship with primary care providers andother specialists mandatory. New approaches to prevention, treatment of chronic PTSD, psychotherapy,pharmacotherapy, and research hold promise of an improved prognosis for patients withPTSD.