Differences in posttraumatic stress disorder diagnostic rates and symptom severity between Criterion A1 and non-Criterion A1 stressors.

This study addresses the ongoing controversy regarding the definition of DSM-IV posttraumatic stress disorder's (PTSD) traumatic stressor criterion (A1). A sample of 119 college students completed the PTSD Symptom Scale separately in relation to both Criterion A1 and non-Criterion A1 stressful events, using a mixed between-groups (administration order) and within-subjects (stressor type) design. Contrary to what was expected, analyses revealed that non-Criterion A1 events were associated with greater likelihood of "probable" PTSD diagnoses and a greater PTSD symptom frequency than Criterion A1 events. Symptom frequency relationships, however, were moderated by the order in which the measures were administered. The non-Criterion A1 PTSD scores were only higher when non-Criterion A1 measures were presented first in the administration order. Similar patterns of differences in PTSD scores between stressor types were also found across the three PTSD symptom criteria. Implications are discussed as to the ongoing controversy of the PTSD construct.