Journal of Consulting and Clinical Psychology 2000. Vol. 68, No. I 290-295 Copyright 2000 by the American Psychological Association, Inc. 0022-006X/OW5.00 DOI: 10.1037»0022-OOnX.68 2.290 Similarity of Prior Trauma Exposure as a Determinant of Chronic Stress Responding to an Airline Disaster Angela Liegey Dougall and Holly B. Herberman University of Pittsburgh Douglas L. Delahanty Kent State University Sabra S. Inslicht and Andrew Baum University of Pittsburgh The cumulative effects of trauma were examined in 108 workers at the site of a major air disaster at 4 time points over a year following the crash. The influence of trauma history on chronic distress and physiological arousal associated with the crash were examined. Stress levels were expected to differ on the basis of the similarity of prior trauma exposure to work at the crash site. Prior traumatic exposure that was "dissimilar" to this type of work was associated with greater vulnerability to crash-related stress, that is, more distress and crash-related intrusions during the year following the crash. Accumulation of a variety of different traumatic experiences appeared to sensitize workers to the new stressor and to perpetuate chronic stress. Understanding the role of trauma history is important for improving interven- tion efforts aimed at alleviating stress following a trauma. Exposure to a traumatic event may result in a variety of psy- chological and physiological sequelae, with some individuals be- ing more resilient and others being more vulnerable to its effects. One factor that may determine the quality and severity of stress experienced in the wake of psychological trauma is one's prior history of traumatic experiences. However, it is not clear whether a history of trauma increases or reduces posttraumatic stress and studies have reported both outcomes (e.g., Andrykowski & Cor- dova, 1998; Burgess & Holmstrom, 1979; Cohen, 1953; Koopman, Classen, & Spiegel, 1994; Morris & Murrell, 1988; Peretz, Haider, Ever-Hadani, & De-Nour, 1994; Resnick, Yehuda, Pitman, & Foy, 1995). One explanation for these variable findings is failure to consider the degree of similarity of prior experiences with the current, or index, trauma. There is some evidence that exposure to stressors that resemble each other may inoculate people and reduce the impact of these stressors, but exposure to different types of traumas may be harmful (e.g., Follette, Polusny, Bechtle, & Naugle, 1996; Morris & Murrell, 1988). The present study inves- tigated this hypothesis, examining trauma histories and stress responses of rescue workers at an airline crash site. Angela Liegey Dougall, Holly B. Herberman, Sabra S. Inslicht, and Andrew Baum, Cancer Institute, Department of Behavioral Medicine and Oncology, University of Pittsburgh; Douglas L. Delahanty, Department of Psychology, Kent State University. This research was supported by Grant MH 54697-01 from the National Institute of Mental Health. Correspondence concerning this article should be addressed to An- drew Baum, Cancer Institute, Department of Behavioral Medicine and Oncology, University of Pittsburgh, 3600 Forbes Avenue, Suite 405, Pittsburgh, Pennsylvania 15213. Electronic mail may be sent to Baum @pcicirs.pci.pitt.edu. Evaluation of trauma history as a risk factor for subsequent distress bridges a significant gap in research on resilience and vulnerability in stress and trauma. The stress vulnerability or sensitization hypothesis suggests that repeated trauma exposure increases the likelihood of a pathological response (e.g., Peretz et al., 1994; van der Kolk & Greenberg, 1987). Recurrent assaults on the victim accumulate, wear down one's resistance, and are asso- ciated with greater impairment. Studies of victims of a variety of traumatic events who have experienced prior traumas support this hypothesis, finding more substantial impact on those with prior histories (e.g., Andrykowski & Cordova, 1998; Koopman et al., 1994; Moran & Britton, 1994; Peretz et al., 1994). In contrast, other studies suggest that prior trauma exposure is beneficial and it has been hypothesized that it fortifies the indi- vidual for future stressful events (e.g., Bolin, 1985; Burgess & Holmstrom, 1979; Cohen, 1953; Morris & Murrell, 1988; Quaran- telli, 1985; Warheit, 1985). Victims habituate to repeated trauma and become toughened and more resilient to subsequent experi- ences. Repeated exposure to a stressful event may serve to nor- malize perceived threat and make the circumstances of unusual events more understandable (Anderson, 1968). Traumatic events, which are often incongruous to a person's prior experience and worldview, must be integrated through reexperiencing the event and cognitive processing. Repeated exposure to trauma may op- erate by lowering one's expectations of safety and security, alert- ing people to the possibility that they will be victimized, and preparing them to more readily process and cope with threatening experiences. Evidence supporting habituation of stressful re- sponses to repeated traumatization (i.e., greater levels of reported positive adjustment and fewer anxiety symptoms) has been found in several victim groups (Antonovsky, Maoz, Dowty, & Wijsen- beek, 1971; Bell, Kara, & Batterson, 1978; Morris & Murrell, 1988). 290 This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.