Peritraumatic and persistent dissociation in the presumed etiology of PTSD.

OBJECTIVE: Dissociative responses that occur at the time of a trauma (peritraumatic dissociation) have been described as a major risk factor for subsequent posttraumatic stress disorder (PTSD). The current study evaluated peritraumatic dissociation and PTSD from a multivariate perspective, along with a less-investigated phenomenon: trauma-specific dissociation that begins during or after an event and continues until the time of assessment (persistent dissociation).
METHOD: In two studies, 52 local community participants and 386 participants from the general population with histories of exposure to at least one traumatic event were assessed for the presence of PTSD and were administered measures of dissociation and peritraumatic distress.
RESULTS: In both studies, peritraumatic dissociation, persistent dissociation, peritraumatic distress, and generalized dissociative symptoms were associated with PTSD by univariate analyses. However, multivariate analyses in both studies indicated that PTSD status was no longer related to peritraumatic dissociation once other variables (especially persistent and generalized dissociation) were taken into account. In contrast, persistent dissociation was a strong predictor at univariate and multivariate levels.
CONCLUSIONS: Trauma-related persistent dissociation is a substantial predictor of PTSD, whereas peritraumatic dissociation ceases to predict PTSD at the multivariate level. These findings suggest that it is less what happens at the time of a trauma (e.g., disrupted encoding) that predicts PTSD than what occurs thereafter (i.e., persistent avoidance).