Does tonic immobility mediate the effects of psychological violence on PTSD and complex PTSD?

Background: Tonic Immobility (TI) is a peri-traumatic response that appear to play a vital role in the development of posttraumatic stress disorder (PTSD). TI is characterized by a strong motoric inhibition, a paralysis of movement, thought, emotion, and vocalization, and has primarily been studied in association with rape and childhood sexual assault. Aim: The present study examines the role of TI in developing ICD-11 PTSD and disturbances in self-organization (DSO) following different types of Intimate partner violence (IPV), i.e., physical, sexual, and psychological violence, in a clinical sample of N = 150 women. Methods: A measurement model for ICD-11 PTSD and DSO was constructed using confirmatory factor analysis and three models were computed to test whether the different subtypes of IPV were directly related to symptom severity, or whether they were partly or fully mediated by TI. Results: Controlling for other types of violence, psychological violence was the only type of violence directly and indirectly related to ICD-11 PTSD and DSO. While most of the relationship consisted of a direct effect, TI acted as a partial mediator of the relationship between psychological violence and PTSD and DSO. Discussion: Results are discussed regarding our understanding of trauma and how psychologically threatening events can elicit a peri-traumatic response of TI, which has previously been associated primarily with threats to life or physical integrity.