Psychobiology of the Trauma Response

Abstract

When Kardiner first described the full syndrome of what is now called posttraumatic stress disorder (PTSD)¹ in 1941 he called it a “physioneurosis,” a mental disorder with both psychological and physiological components. People with PTSD continue to suffer from “enduring vigilance for and sensitivity to environmental threat.” The response to trauma is consistent across traumatic stimuli: The central nervous system has a limited and rather consistent response to terrifying experiences. After a traumatic event most victims go through a period of phasic reliving, with intrusive reexperiences, such as visual images and physiological arousal, alternating with denial and numbing of responsiveness to the environment. In many people the condition becomes chronic, with various degrees of residual symptoms, for example physiological hyperreactivity, a subjective sense of loss of control, chronic passivity alternating with uncontrolled violence against the self or others, sleep disturbances, and reenactments of traumatic events.² Often symptoms become evident only during later periods of life stress, when current stressful events can be experienced as a partial reliving of earlier trauma. The degree to which traumatic experiences become interwoven in the totality of a person’s characterological responses depends on (a) the psychobiological maturation of the victim, (b) the severity of the stressor, (c) the presence of prior traumatizing experiences, and (d) the quality of social support.³ We hypothesize that the emotional and behavioral responses to trauma are driven by neurobiological alterations and propose the following specific postulates.