The psychobiology of posttraumatic stress disorder

This review summarizes the current state of our knowledge of the psychobiology of posttraumatic stress disorder (PTSD). People with PTSD develop an enduring vigilance for and sensitivity to environmental threat. They have difficulty in properly evaluating sensory stimuli and responding with appropriate levels of physiologic and neurohormonal arousal. The inappropriate mobilization of biological emergency responses to innocuous stimuli is mirrored psychologically in an inability to properly integrate memories of the trauma and in a fixation on the past. The biological dysregulation of PTSD can be measured on physiologic, neurohormonal, immunologic, and functional neuroanatomical levels. The developmental level at which the trauma occurs affects the nature and extent of psychobiological disruptions. The availability of neuroimaging for documenting structural and functional abnormalities in PTSD has opened up new ways for understanding the neuronal filters concerned with the interpretation of sensory information in PTSD. These studies have produced a number of unexpected findings, which may alter how we conceptualize PTSD and which may force us to reevaluate appropriate therapeutic interventions.