Characteristics of the posttraumatic stress disorder traumatic stressor : a study of rural and northern first responders

A diagnosis of posttraumatic stress disorder (PTSD) requires meeting Criterion A, which states that the individual must: 1) experience, witness, or be confronted with an event that involved actual or threatened death, serious injury, or threat to one’s physical integrity (Criterion A1); and 2) experience intense fear, helplessness, or horror during or shortly after the event (Criterion A2). Despite various attempts to define Criterion A, a strong etiological link between the event and resulting PTSD has remained elusive. The overarching purpose of the current study was to examine characteristics of traumatic stressors beyond Criterion A. A cross-sectional, repeated-measures design was used to examine Criterion A1 events under two conditions: when an event was associated with lasting distress (i.e., distressing event) and when an event was not associated with lasting distress (i.e., control event). This research addressed four objectives. First, it identified characteristics of Criterion A1 events that evoked extreme amounts of distress (i.e., PTSD symptoms). Second, it examined whether these characteristics were more relevant for distressing events compared to control events. Third, it tested whether event characteristics added incremental value in predicting PTSD symptoms above meeting Criterion A. Finally, it tested hypothesized relationships between event characteristics and processes implicated in cognitive models, namely peritraumatic dissociation and posttrauma cognitions. The present study surveyed 181 first responders from northern British Columbia. First responders repeatedly experience Criterion A1 events, which allowed them to rate the relevance of event characteristics for both types of events. A principal component analysis of diverse event characteristics revealed that distressing events were characterized by chaos and resource limitations, which were both rated as significantly more descriptive of distressing events compared to control events. As hypothesized, both event characteristics predicted PTSD symptoms above meeting Criterion A, which was not associated with PTSD symptoms. Consistent with cognitive models, the event characteristics influenced peritraumatic dissociation and posttrauma cognitions, which in turn predicted PTSD symptoms. Moreover, the affect of the event on PTSD symptoms was partially mediated by these cognitive variables. Overall, the results of this study are novel because they underscore the importance of examining event characteristics beyond Criterion A.Arts, Faculty ofPsychology, Department ofGraduat