Exposure to potentially traumatic events is unfortunately the norm in our society. Individuals who have experienced or witnessed physical and sexual assault or abuse, combat, terrorist acts, torture, natural disasters and those of human origin, or other highly aversive events typically experience some symptoms of posttraumatic stress disorder (PTSD) in the days or weeks following exposure. Yet, in the majority of people, most posttraumatic symptoms disappear by 1 to 3 months following the event, and less than 10% of trauma-exposed individuals in the United States meet criteria for PTSD at some point in their lifetime.

The purpose of this entry is to elucidate biochemical processes and neural circuitry implicated in the psychophysiological impact of trauma, including the development of PTSD. We begin with an introduction to ...