Peritraumatic dissociation mediates the relationship between acute panic and chronic posttraumatic stress disorder.

Although peritraumatic dissociation predicts subsequent posttraumatic stress disorder (PTSD), little is understood about the mechanism of this relationship. This study examines the role of panic during trauma in the relationship between peritraumatic dissociation and subsequent PTSD. Randomized eligible admissions to 4 major trauma hospitals across Australia (n=244) were assessed during hospital admission and within one month of trauma exposure for panic, peritraumatic dissociation and PTSD symptoms, and subsequently re-assessed for PTSD three months after the initial assessment (n=208). Twenty (9.6%) patients met criteria for PTSD at 3-months post injury. Structural equation modeling supported the proposition that peritraumatic derealization (a subset of dissociation) mediated the effect of panic reactions during trauma and subsequent PTSD symptoms. The mediation model indicated that panic reactions are linked to severity of subsequent PTSD via derealization, indicating a significant indirect relationship. Whereas peritraumatic derealization is associated with chronic PTSD symptoms, this relationship is influenced by initial acute panic responses.