Symptoms of dissociation in humans experiencing acute, uncontrollable stress: a prospective investigation

Peritraumatic dissociation has been associated with subsequent development of posttraumatic stress disorder, but supporting data have been largely retrospective. The current study was designed to assess the nature and prevalence of dissociative symptoms in healthy humans experiencing acute, uncontrollable stress during U.S. Army survival training.

In study 1, 94 subjects completed the Clinician-Administered Dissociative States Scale after exposure to the stress of survival training. In study 2, 59 subjects completed the Brief Trauma Questionnaire before acute stress and the dissociative states scale before and after acute stress. A randomly selected group of subjects in study 2 completed a health problems questionnaire after acute stress.

In study 1, 96% of subjects reported dissociative symptoms in response to acute stress. Total scores, as well as individual item scores, on the dissociation scale were significantly lower in Special Forces soldiers compared to general infantry troops. In study 2, 42% of subjects reported dissociative symptoms before stress and 96% reported them after acute stress. Dissociative symptoms before and after stress were significantly higher in individuals who reported a perceived threat to life in the past. Forty-one percent of the variance in reported health problems was accounted for by poststress dissociation scores.

Symptoms of dissociation were prevalent in healthy subjects exposed to high stress. Stress-hardy individuals (Special Forces soldiers) experienced fewer symptoms of dissociation, compared to individuals who were less hardy. These data support the idea that the nature of response to previously experienced threatening events significantly determines the nature of psychological and somatic response to subsequent stress.