The short-term dynamics of posttraumatic stress disorder symptoms during the acute posttrauma period.

Background: The manner in which posttraumatic stress disorder (PTSD) develops remains largely unknown. PTSD is comprised of 20 symptoms across 4 clusters. These clusters were hypothesized to reflect a failure of recovery model in which intrusive symptoms appear first. Intrusive symptoms led to avoidance of trauma-related stimuli, which resulted in sustained arousal. The sustained arousal ultimately led to dysphoria.

Methods: This hypothesized symptom progression was evaluated during the acute posttrauma period (the first 30 days postevent). Participants (N = 80) reported their PTSD symptoms for 30 days via mobile devices. Using a short-term dynamic modeling framework, a temporal and contemporaneous model of PTSD symptoms was obtained.

Results: In the temporal network, a fear-conditioning component was identified that supported the hypothesized set of relations among symptom clusters. The contemporaneous network was classified by two subnetworks. The first corresponded to a fear-conditioning model that included symptoms of intrusions and avoidance. The second included symptoms of dysphoria and arousal.

Conclusions: These findings suggest that, after a trauma, there may be a fear-conditioning process that involves intrusions, avoidance, and arousal symptoms. Dysphoric symptoms were also present but developed as a partially distinct component.