Dissociation, Hardiness, and Performance in Military Cadets Participating in Survival Training

Military Medicine, May 2006 by Eid, Jarle, Morgan, Charles A III

The present study examined the relationship between peritraumatic dissociation, hardiness, and military performance in Norwegian Navy officer cadets (N = 80) after a simulated prisoner of war (POW) exercise. The cadets reported symptoms of peritraumatic amnesia, depersonalization, and derealization in response to a mild stress experience (time point 1) and exhibited a significant increase in such symptoms when subsequently exposed to a highly stressful experience of being placed in a mock POW camp (time point 2). Symptoms of peritraumatic dissociation were significantly and negatively related to performance, and predicted between 16 and 26% of the variance between subjects. A subscale of the personality hardiness measure (i.e., the subdimension of challenge) was negatively associated with peritraumatic dissociation in response to both the mild stress situation and the more stressful POW exercise in study subjects. Hardiness was not significantly associated with military performance scores. The present data indicate that individual differences in attribution style and in a propensity to dissociate significantly affect military performance during exposure to high stress situations.

Introduction

Studies of civilian populations have provided evidence that psychological symptoms of dissociation frequently occur among trauma victims.1"3 These symptoms, which are often referred to as symptoms of "peritraumatic dissociation," have also been thought by a number of clinicians and investigators to be associated with an increased risk for the subsequent development of post-traumatic stress disorder (PTSD).4-7

Until recently, much of the supporting data about the link between peritraumatic symptoms of dissociation and the subsequent development of PTSD has been largely retrospective in nature, which has limited our understanding about the actual frequency and intensity of such symptoms in healthy and clinical populations. Recent retrospective and prospective investigations of healthy subjects exposed to highly stressful events has provided evidence that symptoms of dissociation are common in law enforcement officers involved in critical shooting incidents8 and in military personnel exposed to the acute stress of survival training.9'11 The data from these recent studies suggest that under extremely stressful events all individuals may experience symptoms of dissociation. In the studies of U.S. military personnel exposed to survival training Morgan et al.9,11 found that dissociation was negatively related to performance. Furthermore, a previous history of traumatic stress exposure has also been associated with acute stress reactions and how much dissociation one experienced during stress.9,12 Although the previous studies have demonstrated that dissociation symptoms may be relatively common and somewhat related to one's history of trauma, little is known about the degree to which personality dimensions such as hardiness might be related to symptoms of peritraumatic dissociation.

Personality hardiness is a personality trait or cognitive style marked by increased levels of commitment, control, and challenge,13 which has been associated with good health and high performance under a variety of stressful conditions in both civilian and military samples.14-16 Personality hardiness has been found to serve as a moderator between combat exposure and PTSD.17 It has been proposed that individuals higher in personality hardiness tend to believe that they can control or influence events and that they have a commitment to activities and their interpersonal relationships and to self, in that they recognize their own distinctive values, goals, and priorities in life. People higher in hardiness also tend to interpret stressful events in positive and constructive ways, and construe such events as a challenge and valuable learning opportunity.18 If hardiness encourages individuals to interpret stressful events in positive terms, then hardiness might well lead to increased resilience and adaptability in a highly stressful situation such as survival training. However, the relationship between personality hardiness and stress-induced symptoms of dissociation has not been fully explored.

Thus, the present study was designed to examine the relationship between stress-induced symptoms of dissociation and personality hardiness in healthy subjects. Furthermore, the present study was also designed to explore whether dissociation and hardiness would be significantly related to military performance during exposure to survival training stress. In this study, we had several a priori hypotheses that were based on the findings of our previous investigations: 1) that exposure to acute stress of the prisoner of war (POW) camp experience would elicit symptoms of dissociation; 2) that there would be a negative relationship between symptoms of dissociation and performance; and 3) that personal hardiness would be associated with fewer symptoms of dissociation.

Methods