Psychotraumatology: a two-factor formulation of posttraumatic stress.

Other than the "sudden death" phenomenon, posttraumatic stress represents the most severe and incapacitating form of human stress (Everly, 1989). Posttraumatic stress is directly associated with three DSM-III-R, Axis I disorders: Posttraumatic Stress Disorder (PTSD), Multiple Personality Disorder, and Brief Reactive Psychosis (APA, 1987). It is similarly associated with the Axis II personality disorder Borderline Personality Disorder (Herman and van der Kolk, 1987). Posttraumatic stress may be indirectly related to various forms of mood disorders, substance abuse syndromes, and phobic disorders. Regarding the prevalence of posttraumatic stress, Helzer et al. (1987) found the lifetime prevalence of PTSD at around 1% in the general population. Breslau et al. (1991) found the prevalence of PTSD to be 9% in a cohort of young adults in an urban setting. They further found a prevalence of 24% in young adults who had been exposed to traumatic events. Norman and Getek (1988) have estimated that nearly one-half of all patients admitted to urban trauma centers are likely to suffer from PTSD in addition to their physical traumatization, while another 31% may suffer from a milder variant of posttraumatic stress. These data argue compellingly for the potential severity of the threat that posttraumatic stress poses to society. Yet, no one clear-cut therapy for posttraumatic stress has emerged, nor has a generally agreed-upon phenomenology emerged upon which to base such a therapy. The purpose of this paper is to present a comprehensive formulation of posttraumatic stress based upon an integration of biological and psychological evidence.