Neural correlates of acute post-traumatic dissociation: a functional neuroimaging script-driven imagery study

Abstract

Background Current neurobiological models of post-traumatic stress disorder (PTSD) assume excessive medial frontal activation and hypoactivation of cortico-limbic regions as neural markers of post-traumatic dissociation. Script-driven imagery is an established experimental paradigm that is used to study acute dissociative reactions during trauma exposure. However, there is a scarcity of experimental research investigating neural markers of dissociation; findings from existing script-driven neuroimaging studies are inconsistent and based on small sample sizes. Aims The current aim was to identify the neural correlates of acute post-traumatic dissociation by employing the script-driven imagery paradigm in combination with functional magnetic resonance imaging. Method Functional neuroimaging data was acquired in 51 female patients with PTSD with a history of interpersonal childhood trauma. Blood-oxygen-level-dependent response during the traumatic (versus neutral) autobiographical memory recall was analysed, and the derived activation clusters were correlated with dissociation measures. Results During trauma recall, enhanced activation in the cerebellum, occipital gyri, supramarginal gyrus and amygdala was identified. None of the derived clusters correlated significantly with dissociative symptoms, although patients reported increased levels of acute dissociation following the paradigm. Conclusions The present study is one of the largest functional magnetic resonance imaging investigations of dissociative neural biomarkers in patients with PTSD undergoing experimentally induced trauma confrontation to elicit symptom-specific brain reactivity. In light of the current reproducibility crisis prominent in neuroimaging research owing to costly and time-consuming data acquisition, the current (null) findings highlight the difficulty of extracting reliable neurobiological biomarkers for complex subjective experiences such as dissociation.

Trauma-related dissociation and the autonomic nervous system: a systematic literature review of psychophysiological correlates of dissociative experiencing in PTSD patients

“…Although analyses on resting-state brain activation tentatively support the idea of an overmodulated fear network (see defense cascade and shutdown models) through reports of altered functional connectivity between prefrontal and subcortical areas in dissociative PTSD patients (Nicholson et al, 2017;Nicholson et al, 2019;Rabellino et al, 2018), experimental studies are lacking. The few experimental neuroimaging studies to date (Daniels et al, 2012;Felmingham et al, 2008;Mertens et al, 2022) either report inconsistent brain regions associated with traumarelated dissociation or fail to present any associated neural regions at all. Ultimately, this undermines the proposed neurobiological basis (e.g.…”

Altered brain activity and functional connectivity after MDMA-assisted therapy for post-traumatic stress disorder

“…They were screened for additional neuroimaging related eligibility criteria and were excluded for any conditions that could render MRI unsafe. A script-driven autobiographical memory paradigm was used to assess brain activity during symptom provocation (66)(67)(68). Following baseline CAPS-IV assessment in the parent study, sub-study participants worked with investigators to create two scripts: one describing a personally traumatic event and one reflecting their typical morning routine at home.…”

“…A script-driven autobiographical memory paradigm was used to assess brain activity during symptom provocation (66)(67)(68). We compared whole-brain, script-driven activations (trauma > neutral) at baseline and follow-up (Figure 4).…”

Experimental Induction of Peritraumatic Dissociation: The Role of Negative Affect and Pain and Their Psychophysiological and Neural Correlates

“…Many individuals with Posttraumatic Stress Disorder (PTSD) suffer from dissociative symptoms like depersonalization and derealization (White et al, 2022), which has prompted the introduction of a dissociative PTSD subtype in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 2013). However, while considerable effort has been undertaken to understand psychological and neurobiological processes underlying posttraumatic dissociative states Lanius et al, 2010Lanius et al, , 2018Lebois, Harnett, et al, 2022;Lebois, Kumar, et al, 2022;Mertens et al, 2022;Nicholson et al, 2020;Roydeva & Reinders, 2021;Wolf et al, 2022), little is known about the circumstances under which trauma-related dissociation initially arises, i.e., the causes of and mechanisms behind peritraumatic dissociation.…”