Abstract
Posttraumatic stress disorder (PTSD) is a common psychopathological outcome of sexual assault. Peritraumatic tonic immobility (TI; involuntary "freezing") during sexual assault has been linked with worsened PTSD symptoms, yet little research has examined these effects longitudinally. The present study aimed to examine the effects of TI on the severity of PTSD symptoms, negative posttraumatic cognitions (NPC), and dissociative symptoms over 1 year among 112 female survivors of sexual assault aged 16-30 years. Multilevel linear regressions evaluated the effects of time since sexual assault, TI severity, and their interaction on the severity of PTSD symptoms, NPC (total, blame, self, world), and dissociative symptoms. Results indicated that TI severity was associated with increased NPC, β = .22, p = .018, and dissociative symptom severity, β = .65, p = .037, but not PTSD symptom severity, β = .25, p = .116; these associations remained consistent over time. Given the salience of NPCs, individuals seeking care for TI-associated sexual trauma may benefit from interventions that can reduce NPCs (e.g., prolonged exposure, cognitive processing therapy). Further evaluating these treatments' utility in reducing dissociation may be of particular benefit to individuals with a history of TI reactions during trauma. Finally, coercive rape tactics were associated with increased PTSD symptoms, β = .48, p = .002, whereas forcible, β = -.04, p = .805, and drug- or alcohol-facilitated rape tactics, β = .35, p = .285, were not, indicating the importance of assessing verbal coercion in research and clinical work with individuals who have experienced sexual assault.