The Psychobiology of Posttraumatic Stress Disorder

Article Abstract

This review summarizes the current state of our knowledge of the psychobiology of posttraumaticstress disorder (PTSD). People with PTSD develop an enduring vigilance for and sensitivity to environmentalthreat. They have difficulty in properly evaluating sensory stimuli and responding with appropriatelevels of physiologic and neurohormonal arousal. The inappropriate mobilization of biologicalemergency responses to innocuous stimuli is mirrored psychologically in an inability to properlyintegrate memories of the trauma and in a fixation on the past. The biological dysregulation of PTSDcan be measured on physiologic, neurohormonal, immunologic, and functional neuroanatomical levels.The developmental level at which the trauma occurs affects the nature and extent of psychobiologicaldisruptions. The availability of neuroimaging for documenting structural and functional abnormalitiesin PTSD has opened up new ways for understanding the neuronal filters concerned with theinterpretation of sensory information in PTSD. These studies have produced a number of unexpectedfindings, which may alter how we conceptualize PTSD and which may force us to reevaluate appropriatetherapeutic interventions.