Hotspots in the immediate aftermath of trauma – Mental imagery of worst moments highlighting time, space and motion

A summary review of the development of using a brief imagery-competing task intervention (ICTI) for reducing intrusive memories of psychological trauma: applications in healthcare settings for both staff and patients

Psychological trauma for those utilising and delivering healthcare is common, and in particular the experience of repeated and unwanted intrusive memories (IM) of the trauma can occur. There are several psychological interventions that have been shown to be effective with the full syndrome of Post Traumatic Stress Disorder (PTSD), but researchers have only recently explored targeted interventions for IMs. This review provides a summary of a body of work on a behavioural technique called "Imagery Competing Task Intervention" (ICTI) for intrusive memories after trauma by Holmes and colleagues. The papers presented outline the underlying cognitive science, the historical development of the intervention, and its application to various different populations in healthcare settings including clinical tests of efficacy. Settings and populations include traumatic events experienced by emergency department patients and emergency caesarean section patients, as well as after work-related trauma experienced by intensive care staff and wider healthcare staff. Timing of ICTI intervention delivery has included the same day of trauma, within 72 h and for older memories weeks, months (or years) post-trauma. The intervention has been delivered with a guided session, which in some studies is in person and some remotely via digital health application. There is a brief overview of other related interventions. The ICTI approach shows potential scalability in trauma laden environments such as healthcare, where exposure is unlikely to be limited or managed and symptoms such as subclinical IMs are common. As such the intervention could be used in a preventing-and-treating approach and in subclinical-to-clinical samples who have IMs after exposure to psychological trauma. Future research would be needed to test ICTI as an intervention for the full syndrome of PTSD.

Expanding the toolset of experimental Psychopathology: The Trier Social Stress Test induces a personally relevant emotional memory

Despite the remarkable progress in developing effective psychological interventions for emotional disorders, our understanding of the mechanisms driving therapeutic change remains strikingly limited. To bridge this gap, we need to refine experimental paradigms with high ecological validity and establish their clinical utility. In this study, we replicate and extend previous findings that the Trier Social Stress Test (TSST) can evoke persistent, sensory rich, and personally meaningful emotional memories. One week after the TSST, a student sample (N = 146) reported greater negative valence, arousal, and lack of control in response to TSST-related versus control cues. Participants reported intrusive memories, the content of which reflects the personal relevance, sensory richness, and emotionality of the TSST memory. Re-imagining the TSST through guided imagery evoked heightened emotional responses (skin conductance, heart rate, and self-report) and participants evaluated themselves more negatively due to the TSST. These effects correlated with trait anxiety. However, comparisons to a naïve sample that only experienced the TSST through guided imagery (N = 38) revealed that some findings, including changes in self-image, were not memory-induced. We conclude with concrete examples of how the paradigm can expand our toolset to further unravel mechanistic underpinnings of memory-focused interventions.

Key concepts, methods, findings, and questions about traumatic memories

This article is based on a Lifetime Achievement Award lecture delivered at the 40th Annual Meeting of the International Society for Traumatic Stress Studies in Boston (Massachusetts, United States) in September 2024. Understanding traumatic memory involves integrating clinical observations with a wide range of knowledge from philosophy, cognitive and social psychology, and neuroscience. I present definitions of traumatic memory; distinguish voluntary from involuntary forms, such as flashbacks; and introduce relevant concepts that can situate the clinical symptom within a wider framework. The distinction between flashbacks and standard episodic memory has important implications, and I discuss how the methods used to study traumatic memory can preserve it. Using this same perspective, I then review emerging evidence concerning the nature, neural underpinnings, and origin of traumatic memories. The final section reviews some significant unanswered questions for the future. These include the impact of traumatic memories on the experience of self and the implications of delayed onsets for postulating a family of posttraumatic stress disorders with different underlying mechanisms.

Reducing the Number of Intrusive Memories of Work-Related Traumatic Events in Frontline Health Care Staff During the COVID-19 Pandemic: Case Series

BACKGROUND

Frontline health care staff are frequently exposed to traumatic events as part of their work. Although this study commenced before the emergence of COVID-19, levels of exposure were heightened by the pandemic. Many health care staff members report intrusive memories of such events, which can elicit distress, affect functioning, and be associated with posttraumatic stress disorder symptoms in the long term. We need evidence-based interventions that are brief, preventative, nonstigmatizing, suitable for the working lives of frontline health care staff, and effective for repeated trauma exposure. A brief, guided imagery-competing task intervention involving a trauma reminder cue and Tetris gameplay may hold promise in this regard, given evidence that it can prevent and reduce the number of intrusive memories following trauma across various settings.

OBJECTIVE

This case series aims to investigate the impact of a brief imagery-competing task intervention on the number of intrusive memories, general functioning, and symptoms of posttraumatic stress, anxiety, and depression, and examine the feasibility and acceptability of the intervention for UK National Health Service frontline health care staff. The intervention was delivered with guidance from a clinical psychologist.

METHODS

We recruited 12 clinical staff from the UK National Health Service, specifically from emergency departments, the intensive care unit, and the ambulance service. We evaluated the intervention using an AB single-case experimental design, where the baseline (A) was the monitoring-only phase and the postintervention (B) period was the time after the intervention was first administered. Methods were adapted once the COVID-19 pandemic began.

RESULTS

There was a decrease (59%) in the mean number of intrusive memories per day from baseline (mean 1.29, SD 0.94) to postintervention (mean 0.54, SD 0.51). There was a statistically significant reduction in the number of intrusive memories from baseline to postintervention, as shown by an aggregated omnibus analysis with a small effect size (τ-U=-0.38; P<.001). Depression, anxiety, and posttraumatic stress symptoms all significantly reduced from preintervention to postintervention. Participants also reported improvements in functioning based on both quantitative and qualitative measures. The intervention was feasible to deliver and rated as acceptable by participants.

CONCLUSIONS

These preliminary findings suggest that this brief therapist-guided imagery-competing task intervention offers a potential approach to mitigating the impact of work-related traumatic events in frontline health care staff, both during a pandemic and beyond. Randomized controlled trials will be an important next step.

A systematic review and meta-analysis of experimental methods for modulating intrusive memories following lab-analogue trauma exposure in non-clinical populations

Experiencing trauma leads to intrusive memories (IMs), a hallmark symptom of post-traumatic stress disorder (PTSD), which also occurs transdiagnostically. Understanding why IMs increase or decrease is pivotal in developing interventions to support mental health. In this preregistered meta-analysis (PROSPERO: CRD42021224835), we included 134 articles (131 techniques, 606 effect sizes and 12,074 non-clinical participants) to investigate how experimental techniques alter IM frequency, intrusion-related distress and symptoms arising from lab-analogue trauma exposure. Eligible articles were identified by searching eight databases until 12 December 2023. To test potential publication biases, we employed methods including Egger's test and three-parameter selection models. We employed three-level multilevel modelling and meta-regressions to examine whether and how experimental techniques would modulate IM frequency and associated outcomes. Results showed that techniques (behavioural, pharmacological, neuromodulation) significantly reduced intrusion frequency (g = 0.16, 95% confidence interval [0.09, 0.23]). Notably, techniques aimed to reduce IMs also ameliorated intrusion-related distress and symptoms, while techniques that increased IMs exacerbated these related outcomes, thus highlighting IM's centrality in PTSD-like symptoms. Techniques tapping into mental imagery processing (for example, trauma reminder followed by playing Tetris) reduced intrusions when administered immediately after, or at a delayed time after trauma. Although our meta-analysis is limited to symptoms induced by lab-analogue trauma exposure, some lab-based results have now generalized to real-world trauma and IMs, highlighting the promising utility of lab-analogue trauma paradigms for intervention development.

A model for secondary traumatic stress following workplace exposure to traumatic material in analytical staff

Analytical professionals working in criminal justice and in social media companies are exposed to aversive details of traumatic events. Albeit indirect, exposure in these roles is repeated and can be extreme, including exposure to material containing lethal violence, sexual assault, and serious self-harm, leading to post-traumatic stress disorder and Secondary Traumatic Stress reactions. Incorporating relevant empirical research, this article considers the mechanisms that may contribute to post-exposure post-traumatic stress disorder and Secondary Traumatic Stress reactions in these roles. Building on the Ehlers and Clark model, subsequent extensions, and the authors' experience of working as, and conducting research with, law enforcement professionals, a new model is proposed to explain post-exposure post-traumatic stress disorder/Secondary Traumatic Stress reactions.

Reducing intrusive memories after trauma via an imagery-competing task intervention in COVID-19 intensive care staff: a randomised controlled trial

Intrusive memories (IMs) after traumatic events can be distressing and disrupt mental health and functioning. We evaluated the impact of a brief remotely-delivered digital imagery-competing task intervention on the number of IMs for intensive care unit (ICU) staff who faced repeated trauma exposure during the COVID-19 pandemic using a two-arm, parallel-group, single-blind randomised controlled trial, with the comparator arm receiving delayed access to active treatment (crossover). Eligible participants worked clinically in a UK NHS ICU during the pandemic and had at least 3 IMs of work-related traumatic events in the week before recruitment. Participants were randomly assigned (1:1) to immediate (weeks 1-4) or delayed (weeks 5-8) intervention access. Sequential Bayesian analyses to optimise the intervention and increase trial efficiency are reported elsewhere [1]. The primary endpoint for the pre-specified frequentist analysis of the final study population compared the number of IMs experienced in week 4 between the immediate and delayed access arms. Secondary outcomes included clinical symptoms, work functioning and wellbeing. Safety was assessed throughout the trial by scheduled questions and free report. All analyses were undertaken on an intention-to-treat basis (86 randomised participants). There were significantly fewer intrusive memories during week 4 in the immediate (median = 1, IQR = 0-3, n = 43), compared to the comparator delayed arm (median = 10, IQR = 6-17, n = 43), IRR 0.31, 95% CI: 0.20-0.48, p < 0.001. After crossover, the delayed arm also showed a significant reduction in IMs at week 8 compared to week 4. There were convergent findings for symptoms of PTSD, insomnia and anxiety, work engagement and burnout, general functioning and quality of life. The intervention was found safe and acceptable to participants. All adverse events were unrelated to the study. Our study provides the first evidence of a benefit on reducing IMs, improving other clinical symptoms, work functioning and wellbeing, as well as safety of a brief remotely-delivered digital imagery-competing task intervention. An efficacy trial with an active control and longer follow-up is warranted. The trial is registered at ClinicalTrials.gov (NCT04992390).

Treating intrusive memories after trauma in healthcare workers: a Bayesian adaptive randomised trial developing an imagery-competing task intervention

Intensive care unit (ICU) staff continue to face recurrent work-related traumatic events throughout the COVID-19 pandemic. Intrusive memories (IMs) of such traumatic events comprise sensory image-based memories. Harnessing research on preventing IMs with a novel behavioural intervention on the day of trauma, here we take critical next steps in developing this approach as a treatment for ICU staff who are already experiencing IMs days, weeks, or months post-trauma. To address the urgent need to develop novel mental health interventions, we used Bayesian statistical approaches to optimise a brief imagery-competing task intervention to reduce the number of IMs. We evaluated a digitised version of the intervention for remote, scalable delivery. We conducted a two-arm, parallel-group, randomised, adaptive Bayesian optimisation trial. Eligible participants worked clinically in a UK NHS ICU during the pandemic, experienced at least one work-related traumatic event, and at least three IMs in the week prior to recruitment. Participants were randomised to receive immediate or delayed (after 4 weeks) access to the intervention. Primary outcome was the number of IMs of trauma during week 4, controlling for baseline week. Analyses were conducted on an intention-to-treat basis as a between-group comparison. Prior to final analysis, sequential Bayesian analyses were conducted (n = 20, 23, 29, 37, 41, 45) to inform early stopping of the trial prior to the planned maximum recruitment (n = 150). Final analysis (n = 75) showed strong evidence for a positive treatment effect (Bayes factor, BF = 1.25 × 106): the immediate arm reported fewer IMs (median = 1, IQR = 0-3) than the delayed arm (median = 10, IQR = 6-16.5). With further digital enhancements, the intervention (n = 28) also showed a positive treatment effect (BF = 7.31). Sequential Bayesian analyses provided evidence for reducing IMs of work-related trauma for healthcare workers. This methodology also allowed us to rule out negative effects early, reduced the planned maximum sample size, and allowed evaluation of enhancements. Trial Registration NCT04992390 ( www.clinicaltrials.gov ).

A systematic review and meta-analysis of the effect of cognitive interventions to prevent intrusive memories using the trauma film paradigm

There is an unmet need for effective early interventions that can relieve initial trauma symptoms and reduce symptoms of posttraumatic stress disorder (PTSD). We evaluated the efficacy of cognitive interventions compared to control in reducing intrusion frequency and PTSD symptoms in healthy individuals using the trauma film paradigm, in which participants view a film with aversive content as an experimental analogue of trauma exposure. A systematic literature search identified 41 experiments of different cognitive interventions targeting intrusions. In the meta-analysis, the pooled effect size of 52 comparisons comparing cognitive interventions to no-intervention controls on intrusions was moderate (g = -0.46, 95% CI [-0.61 to -0.32], p < .001). The pooled effect size of 16 comparisons on PTSD symptoms was also moderate (g = -0.31, 95% CI [-0.46 to -0.17], p < .001). Both visuospatial interference and imagery rescripting tasks were associated with significantly fewer intrusions than controls, whereas verbal interference and meta-cognitive processing tasks showed nonsignificant effect sizes. Interventions administered after viewing the trauma film showed significantly fewer intrusions than controls, whereas interventions administered during film viewing did not. No experiments had low risk of bias (ROB), 37 experiments had some concerns of ROB, while the remaining four experiments had high ROB. To the best of our knowledge, this is the first meta-analysis investigating the efficacy of cognitive interventions targeting intrusions in non-clinical samples. Results seem to be in favour of visuospatial interference tasks rather than verbal tasks. More research is needed to develop an evidence base on the efficacy of various cognitive interventions and test their clinical translation to reduce intrusive memories of real trauma.

Qualitative analysis of hotspots and intrusive memories after viewing an aversive film highlights their sensory and spatial features

Intrusive memories of trauma are recurrent distressing sensory-perceptual impressions of the traumatic event that enter consciousness spontaneously and unwanted. They often contain the worst moment/s ('hotspots') of the trauma memory and have primarily been studied in clinical populations after real trauma. Intrusive memories can also be studied using analogue trauma as an 'experimental psychology model'. Little is known about the features of analogue trauma hotspots. Here we report an ancillary analysis of data from a randomized controlled trial. Seventy non-clinical participants viewed a trauma film containing COVID-19 related footage. Features of hotspots/intrusive memories of the film were explored using linguistic analysis and qualitative content coding. Participants reported on average five hotspots (M = 9.5 words/hotspot). Akin to hotspots soon after real trauma, analogue hotspots/intrusions primarily contained words related to space. Most contained sensory features, yet few cognitions and emotions. Results indicate that features of analogue trauma hotspots mirror those of hotspots soon after real trauma, speaking to the clinical validity of this 'experimental psychology model'.ClinicalTrials.gov ID: NCT04608097, registered on 29/10/2020.