Peritraumatic tonic immobility is associated with PTSD symptom severity in Brazilian police officers: a prospective study

Abstract

Objective: Peritraumatic reactions feature prominently among the main predictors for development of posttraumatic stress disorder (PTSD). Peritraumatic tonic immobility (PTI), a less investigated but equally important type of peritraumatic response, has been recently attracting the attention of researchers and clinicians for its close association with traumatic reactions and PTSD. Our objective was to investigate the role of PTI, peritraumatic panic, and dissociation as predictors of PTSD symptoms in a cohort of police recruits (n=132). Methods: Participants were asked to complete the following questionnaires during academy training and after the first year of work: Posttraumatic Stress Disorder Checklist -Civilian Version (PCL-C), Physical Reactions Subscale (PRS), Peritraumatic Dissociative Experiences Questionnaire (PDEQ), Tonic Immobility Scale (TIS), and Critical Incident History Questionnaire. Results: Employing a zero-inflated negative binomial regression model, we found that each additional point in the TIS was associated with a 9% increment in PCL-C mean scores (RM = 1.09), whereas for PRS, the increment was 7% (RM = 1.07). As the severity of peritraumatic dissociation increased one point in the PDEQ, the chance of having at least one symptom in the PCL-C increased 22% (OR = 1.22). Conclusions: Our findings highlight the need to expand investigation on the incidence and impact of PTI on the mental health of police officers.

The role of tonic immobility and control in the development of intrusive memories after experimental trauma

“…Our results regarding spontaneous TI are in line with several retrospective cross-sectional studies in which TI was found to be associated with PTSD development (Bovin et al, 2008;Hagenaars, 2016;Heidt et al, 2005;Humphreys, Sauder, Martin, & Marx, 2010). Together with the findings of one prospective study (Maia et al, 2015) and replicating one experimental study (Hagenaars & Putman, 2011), our findings suggest that spontaneous TI during (analogue) trauma contributes to the development of intrusive trauma memories and PTSD. Moreover, the overall association between TI and intrusion frequency in our study was similar to the correlation reported by Hagenaars and Putman (2011).…”

Fear and the Defense Cascade

“…Tonic immobility is also sometimes—but not always—included within the construct of peritraumatic reactions (which include symptoms of panic, dissociation, and sometimes tonic immobility). 107 – 109 Because tonic immobility includes a subjective experience of derealization and depersonalization, it has sometimes been conceptualized as a subtype of dissociation (see Supplemental Text Box 4, http://links.lww.com/HRP/A11 ). Lanius (2014) 110 hypothesizes that symptoms of derealization and depersonalization during tonic immobility and other dissociative states may be mediated by kappa opioids—also known as dynorphins—because their activation has been documented in experiments of tonic immobility in animals 111 – 113 and because they are known to cause disturbances in the perception of space and time, abnormal visual experiences, disturbances in body-image perception, and depersonalization and derealization in humans.…”

The effects of trauma on brain and body: A unifying role for the midbrain periaqueductal gray

“…The inescapable nature of the experience, coupled with the overwhelming threat, is thought to promote dissociation as an adaptive coping strategy in humans (Krause‐Utz, Frost, Winter, & Elzinga, ; Nijenhuis, Vanderlinden, et al, ; Spiegel & Cardeña, ; Vermetten & Spiegel, ). Here, dissociation may evoke a subjective detachment (i.e., depersonalization, derealization, emotional numbing) from the trauma experience by dampening emotional reactivity and altering conscious arousal (Maia et al, ; Popova, Barykina, Plyusnina, Alekhina, & Kolpakov, ; for a review, see Scaer, ; Schauer & Elbert, ).…”