Dissociation and memory fragmentation in post-traumatic stress disorder: an evaluation of the dissociative encoding hypothesis

A systematic review of post-traumatic growth in ambulance personnel: facilitators and prevalence rates

Introduction

Ambulance personnel are exposed to traumatic and stressful situations, which can increase the risk of mental health conditions, such as post-traumatic stress disorder (PTSD). High rates of PTSD have been found in ambulance personnel (Petrie et al., 2018), but no review is available to examine post-traumatic growth (PTG - positive psychological change following a trauma) in this population. This literature review provides an overview of the prevalence rates and facilitators that may contribute to PTG in ambulance personnel.

Methods

A systematic search was conducted on EBSCOhost in January 2024 across the following six databases: Academic Search Ultimate, PsycINFO, PsycARTICLES, MEDLINE, ERIC and Cumulative Index to Nursing and Allied Health Literature (CINAHL) Ultimate.

Results

Eleven papers were identified for this review. Pooled prevalence of PTG was moderate (52%), and facilitators for PTG were grouped into five categories: coping style/strategies, resilience, personality traits, gender and incident characteristics.

Conclusions

Numerous facilitators contributed to the development of PTG, although these did not arise in all papers. The quality of research ranged from satisfactory to excellent. Evidence suggested that adaptive coping style, high levels of resilience, the absence of a personality trait (neuroticism) and being female may facilitate PTG. Further research is needed to support the reliability of findings.

Integrating and fragmenting memories under stress and alcohol

Stress can powerfully influence the way we form memories, particularly the extent to which they are integrated or situated within an underlying spatiotemporal and broader knowledge architecture. These different representations in turn have significant consequences for the way we use these memories to guide later behavior. Puzzlingly, although stress has historically been argued to promote fragmentation, leading to disjoint memory representations, more recent work suggests that stress can also facilitate memory binding and integration. Understanding the circumstances under which stress fosters integration will be key to resolving this discrepancy and unpacking the mechanisms by which stress can shape later behavior. Here, we examine memory integration at multiple levels: linking together the content of an individual experience, threading associations between related but distinct events, and binding an experience into a pre-existing schema or sense of causal structure. We discuss neural and cognitive mechanisms underlying each form of integration as well as findings regarding how stress, aversive learning, and negative affect can modulate each. In this analysis, we uncover that stress can indeed promote each level of integration. We also show how memory integration may apply to understanding effects of alcohol, highlighting extant clinical and preclinical findings and opportunities for further investigation. Finally, we consider the implications of integration and fragmentation for later memory-guided behavior, and the importance of understanding which type of memory representation is potentiated in order to design appropriate interventions.

Exploring intrusions without awareness: A preliminary study of the characteristics and influences of meta-awareness failures

BACKGROUND AND OBJECTIVES

Research shows that people can lack meta-awareness (i.e., being explicitly aware) of their trauma-related thoughts, which impacts our understanding of re-experiencing symptoms, a key symptom type in posttraumatic stress disorder (PTSD), assessed through self-report. This preliminarily study explored differences between (meta-)aware and unaware intrusion characteristics to understand why some intrusions are not immediately apparent to individuals.

METHODS

Trauma-exposed participants (N = 78) were recruited from online crowd-sourcing platforms to complete an online meta-awareness task. During a reading task, participants were intermittently probed to index the occurrence of unreported (i.e., unaware) trauma-related intrusions. Once participants indicated trauma-related intrusions were present, they then completed a questionnaire that indexed intrusion characteristics.

RESULTS

Although unaware intrusions did occur in a subset of the sample, there were no fundamental differences between aware and unaware intrusions in terms of modality of experience (imagery vs. non-imagery), meaningfulness, accessibility, or other characteristics (e.g., vividness).

LIMITATIONS

There was potential for lower participant engagement and attention due to the online delivery of the meta-awareness task, which may have minimized meta-awareness failure. Future research could consider using a continuous measure to index levels of meta-awareness. In addition, recruiting clinical samples (e.g., individuals with PTSD) who typically experience multiple daily intrusions would allow generalizability of the current findings to be tested.

CONCLUSIONS

Our findings from this preliminary study suggest that unaware and aware intrusions show more commonality than not in their characteristics, with further research required to improve our understanding of the mechanisms leading to meta-awareness or lack of in PTSD.

Narrative Review of the Complex Interaction between Pain and Trauma in Children: A Focus on Biological Memory, Preclinical Data, and Epigenetic Processes

The incidence and collective impact of early adverse experiences, trauma, and pain continue to increase. This underscores the urgent need for translational efforts between clinical and preclinical research to better understand the underlying mechanisms and develop effective therapeutic approaches. As our understanding of these issues improves from studies in children and adolescents, we can create more precise preclinical models and ultimately translate our findings back to clinical practice. A multidisciplinary approach is essential for addressing the complex and wide-ranging effects of these experiences on individuals and society. This narrative review aims to (1) define pain and trauma experiences in childhood and adolescents, (2) discuss the relationship between pain and trauma, (3) consider the role of biological memory, (4) decipher the relationship between pain and trauma using preclinical data, and (5) examine the role of the environment by introducing the importance of epigenetic processes. The ultimate scope is to better understand the wide-ranging effects of trauma, abuse, and chronic pain on children and adolescents, how they occur, and how to prevent or mitigate their effects and develop effective treatment strategies that address both the underlying causes and the associated physiological and psychological effects.

Peri-Traumatic Dissociation and Tonic Immobility as Severity Predictors of Posttraumatic Stress Disorder After Rape

Some individuals show abnormal reactions to extreme fear and life-threatening situations, including tonic immobility (TI) and peri-traumatic dissociation (PTD). We aimed to investigate the association of TI and PTD with posttraumatic stress disorder (PTSD) in women who experienced sexual violence and the risk factors for PTD occurrence. We compared PTSD severity in 86 young adult women with PTSD after a sexual violence exposure grouped according to the presence of PTD and TI. In addition, we investigated whether PTD is associated with depression and anxiety symptoms and assessed potential risk factors for PTD reaction. We found a significant positive correlation between PTSD severity and PTD occurrence (R² = .132; p = .001). PTD was also positively correlated with all clusters of PTSD symptoms except the Clinician-Administered PTSD Scale avoidance cluster (p = .058). PTD was strongly correlated with anxiety (R² = .619; p < .001) and depressive symptoms (R² = .547; p < .001). Multiple logistic regression showed that history of physical abuse (odds ratio [OR]: 1.386; p = .011) and sexual abuse (OR: 1.947; p = .004) during childhood were associated with PTD occurrence. Other risk factors for PTD were having less years of study (OR: 0.216; p = .016) and lower income (OR: 7.403; p = .028). TI measures were available for a subsample of 29 women. We found no association between TI and PTSD severity. PTD, but not TI, is significantly associated with more severe PTSD, depressive, and anxiety symptoms. Less-educated women with a history of childhood abuse and a lower income are at risk of PTD occurrence during a sexual violence episode.

Breaking the cycles of violence with narrative exposure: Development and feasibility of NETfacts, a community-based intervention for populations living under continuous threat

BACKGROUND

Interpersonal violence damages mental health and frequently leads to aggressive defence strategies. If survivors are subsequently blamed for the events, both consequences worsen. Stigma flourishes, especially when survivors are silenced so that details of the trauma remain unknown. Breaking the secrecy both at the individual and collective level is key to enable the healing and reconciliation of individuals and communities living under continuous threat.

METHOD

The NETfacts health system is a stepped care model with three components: (1) Narrative Exposure Therapy (NET), an evidence-based trauma therapy that includes survivor testimony (2) NET for Forensic Offender Rehabilitation (FORNET) acknowledges that perpetrators are frequently also victims and assists in reducing aggression and the attraction to violence, and (3) a community intervention disseminating and discussing Facts derived from NET treatment (NETfacts) to challenge the collective avoidance of atrocities and other traumatic material. The intervention was piloted in a community with 497 adult residents in Eastern Democratic Republic of Congo. The willingness of clients to consent to sharing their anonymised testimonies (with a focus on sexual violence survivors and ex-combatants) was investigated, together with other components of feasibility including security and clinical safety, extent of support of respected local authorities and participation rates. As secondary outcomes, clinical and social measures were assessed before and post NETfacts among 200 village residents of whom 160 self-enrolled and 40 had not participated in any form of treatment.

RESULTS

Implementation was feasible with 248 clients from a partner project giving consent to use their testimonies and high support of respected local authorities and participation rates (56% of residents self-enrolled in NETfacts). Immediate beneficial effects were shown for posttraumatic stress and rejection of rape myths among NETfacts participants who experienced multiple traumatic events in their own past. Attitudes towards ex-combatants improved and the perceived lack of social acknowledgement after trauma increased independent from participation. No significant change was observed for depressive symptoms.

CONCLUSION

NETfacts is a feasible and promising approach to challenge the culture of secrecy surrounding trauma, suppression and social exclusion. Long term effectiveness requires further evaluation.

Disclosure among Youth Stopped by the Police: Repercussions for Mental Health

Police contact is a common and consequential experience disproportionately endured by youth of color living in heavily surveilled neighborhoods. Disclosing police contact to others (including parents, siblings, or friends) may buffer against the harmful mental health repercussions of police contact, but little is known about the relationship between disclosure of police contact and mental health. We use data from the Fragile Families and Child Wellbeing Study, a cohort of urban children born around the turn of the 21st century and followed through age 15, to examine the relationship between disclosure of police contact and mental health among youth. Results suggest three conclusions. First, youth who experience police contact (regardless of whether they disclose this contact) report more depressive symptoms and anxiety than youth who do not experience police contact. Second, among youth who experience police contact, disclosure is associated with significantly less anxiety (but is not significantly associated with depressive symptoms). Third, this protective nature of disclosure is concentrated among Black youth and boys. Taken together, these findings suggest that disclosing police contact, particularly for groups most likely to experience it, may ameliorate some of the harmful mental health repercussions of this contact for youth.

Psychiatric reaction of an intensive care unit survivor in the context of coronavirus disease 2019: a case report

Background

The coronavirus disease 2019 pandemic has had a serious impact on global mental health, particularly in intensive care unit survivors. Given the lethal potential and unpredictability of coronavirus disease 2019, a high risk of posttraumatic stress disorder was identified in the beginning of the crisis. There are insufficient details in current literature and no official guidelines available for the treatment and follow-up of acute stress disorder and the prevention of posttraumatic stress disorder for intensive care unit survivors in the context of coronavirus disease 2019.

Case presentation

We hereby describe a 67-year-old Swiss patient presenting a psychiatric reaction in the context of coronavirus disease 2019. He was admitted to the intensive care unit due to severe acute respiratory distress syndrome from severe acute respiratory syndrome coronavirus 2 and intubated for 13 days. Afterwards, there was a severe worsening of acute renal failure prompting hemodialysis, and he developed delirium. Psychiatric liaison was requested 4 days post-intubation because the patient presented residual symptoms of delirium, false memories about the real context of his medical care, and ideas of persecution toward medical caregivers. He suffered from a very strong peritraumatic reaction, then developed an acute stress disorder linked with his care on the intensive care unit. We looked for strategies to prevent progression from acute stress disorder to posttraumatic stress disorder. We proceeded to the following therapeutic interventions: intensive psychiatric follow-up, intensive care unit diary, and low-dose antipsychotic treatment. The aim of our psychotherapeutic approach was to allow him to increase his feeling of security and to cope with the reality of his traumatic experience. He showed clinical improvement in his mental state after 3 months, despite several predictive factors of evolution to post-intensive care unit posttraumatic stress disorder.

Conclusion

This case report illustrates how a delusional clinical presentation after intensive care in the context of coronavirus disease 2019 can hide psychotraumatic symptoms. It is important to highlight that the intensive care unit diary completed by the intensive care team and the follow-up by the psychiatric liaison team helped the patient reconstruct an appropriate and coherent account. Further studies are needed to determine the psychiatric effects of coronavirus disease 2019 and to assess early and appropriate psychiatric intervention for patients hospitalized for coronavirus disease 2019 to prevent posttraumatic stress disorder.

Dissociation and false memory: the moderating role of trauma and cognitive ability

The term dissociation is often used to refer to a diverse range of psychological symptoms, including perceptual impairments, emotional detachment, and memory fragmentation. In the present study, we examined whether there was a relation between participants' self-reports of dissociative experiences and their memory performance in the Deese-Roediger-McDermott (DRM) paradigm-a laboratory-based procedure that is frequently used to investigate false memory. University students (N = 298) completed the Dissociative Experiences Scale (DES) and the Traumatic Life Events Questionnaire (TLEQ). Participants were also administered a standardised intelligence test (Shipley-2), and they were tested in the DRM paradigm. Overall, experiencing trauma and dissociation, as well as lower levels of cognitive ability, were associated with higher false memory. These findings are discussed in the context of the activation monitoring theory of DRM false memory.

Impact of peritraumatic dissociation in hospitalized patients with COVID-19 pneumonia: A longitudinal study

OBJECTIVE

Psychiatric impact of COVID-19 is still explored and previous data suggest potential risks of anxiety, depression and PTSD related to COVID-19. We aimed to explore the predictive value of risk factors during hospitalization (T0) for COVID-19 for anxiety, depression and PTSD and at three months (T1) because they could differ over these two time points.

METHODS

We performed a screening of mental suffering in hospitalized patients for COVID-19, as well as specialized care and three months longitudinal follow-up. We evaluated at T0 and at T1 the prevalence of anxiety, depression and PTSD in survivors who benefited from early detection and treatment, and assessed possible risk factors in adults surviving COVID-19 between the 30th March and the 1^st of July 2020.

RESULTS

109 patients were screened at T0 and 61 of these were reassessed at T1. At T0, we found 44.9% pathological score on peritraumatic dissociation experiences questionnaire (PDEQ), 85.4% of post-traumatic stress disorder symptoms (PTSS), 14.6% of pathological rate of post-traumatic stress disorder scale 5 (PCL5) and at T1, 86.9% of PTSS, 10.6% of pathological rate of PCL5. Finally, PDEQ score at T0 during hospitalization was positively correlated to PCL-5 score at T1 (β = 0.26, p = 0.01) and that was confirmed in multivariate analysis (β = 0.04, p = 0.02 for the log of PCL-5 per point on the PDEQ).

CONCLUSION

Screening of psychiatric symptoms during hospitalization for COVID-19 should be systematic, especially peritraumatic dissociation to offer an early treatment and prevent PTSD, which seemed frequent for hospitalized patients for COVID-19 at three months.

The Relationship Between Experiential Avoidance and Posttraumatic Stress Symptoms: A Moderated Mediation Model Involving Dissociation, Guilt, and Gender

Experiential avoidance, dissociation, and guilt have been shown to be associated with trauma exposure and to play an important role in explaining the development and maintenance of posttraumatic stress symptoms. However, there is a lack of studies that simultaneously address the relationship between these variables, which has never been studied within the framework of emotional processing theory. Furthermore, gender differences in traumatic victimization, posttraumatic stress symptoms, experiential avoidance, dissociation, and guilt have also been reported. Therefore, this study had a double aim: a) to assess the mediating roles of dissociation and guilt in the relationship between experiential avoidance and posttraumatic stress symptoms; and b) to investigate whether gender moderates any such relationship. The final sample comprised 683 undergraduate students (150 men and 533 women) with a history of exposure to traumatic events and with posttraumatic stress symptoms. Mediation and moderated mediation analyses were conducted. Dissociation and guilt independently mediated the association between experiential avoidance and posttraumatic stress symptoms: however, this mediation effect was not moderated by gender. The findings suggest that interventions aimed at controlling psychological variables linked to PTSD (i.e. experiential avoidance, dissociation, and guilt) may be of help to both men and women.

NETfacts: a community intervention integrating trauma treatment at the individual and collective level

The aim of this article is to present a research-based rationale for NETfacts, a newly developed integrated approach at the individual and the community level in order to mitigate the mental and social sequelae of war and crisis. To this end, we provide a selective review of relevant literature from neuroscience, clinical psychology, and social science. In psychotraumatology, individual avoidance describes the effort to prevent exposure to trauma reminders. Among patients with post-traumatic stress disorder (PTSD), this becomes pathological, exacerbating distress and preventing recovery. This silence resonates in traumatized communities and consequently taboo builds - ultimately to the advantage of the perpetrators. The resulting collective avoidance leads to a fragmented collective memory about trauma or human rights violations in the community so that a shared account of the group's history becomes impossible. The deficient collective memory promotes ambiguous truths and anxiety, enabling a reactive construction of safety based on selective information that leads to an endorsement of extreme opinions. Ongoing insecurity, violence and crime lead to increasing anxiety and fear. The self-interest of the perpetrators and the abnormal behaviour of survivors leads to an escalation in stigma and social exclusion resulting in the prevention or limitation of community exposure to traumatic material, i.e., to reduce tension and protect the construction of safety. The exposure to and recognition of traumatic facts subject to avoidance is key to a coherent collective memory and sense of communion, and to prevent further cycles of violence. The NETfacts health system combines individual and community-based intervention to treat the structure of memory at both the individual and collective levels. Abbreviations: NET: narrative exposure therapy; FORNET: narrative exposure therapy for forensic offender rehabilitation; NETfacts: facts derived from narrative exposure therapy.

Negative item memory and associative memory: Influences of working memory capacity, anxiety sensitivity, and looming cognition

BACKGROUND AND OBJECTIVES

Traumatic or negative stimuli facilitate item memory but impair associated context memory. Vulnerability factors related to the maintenance and onset of posttraumatic stress disorder (PTSD), such as anxiety sensitivity, looming cognitive style, dissociation, and low working memory capacity, have been identified. However, little is known about how these factors influence negative item or associative memory.

METHODS

Eighty-five undergraduates completed self-report questionnaires, the operation span with words (OSPAN) task, and an item and associative memory task in which incidental encoding of negative and neutral items and context information (Day 1) was followed by an unexpected retrieval test (Day 2).

RESULTS

The results showed greater Hit rates and False Alarms on item memory and lower accuracy on context memory with negative stimuli than with neutral stimuli, replicating previous findings. Low working memory capacity and high dissociation were correlated with low negative item memory. Under low working memory capacity, high levels of anxiety sensitivity and looming cognitive style predicted high dissociation levels and low accuracy for negative item memory. There were no individual differences involving associative memory.

LIMITATIONS

A nonclinical sample was used, which limits the generalizability of our results to clinical samples.

CONCLUSIONS

Dissociation could be a coping strategy for reducing negative item memory. Anxiety sensitivity and looming cognitive style facilitate dissociative coping; however, working memory capacity buffers against these vulnerabilities.

Emotional conflict adaptation predicts intrusive memories

Why do some individuals experience intrusive emotional memories following stressful or traumatic events whereas others do not? Attentional control may contribute to the development of such memories by shielding attention to ongoing tasks from affective reactions to task-irrelevant emotional stimuli. The present study investigated whether individual differences in theability to exert cognitive control are associated with experiencing intrusive emotional memories after laboratory trauma. Sixty-one healthy women provided self-reported and experimentally derived measures of attentional control. They then viewed a trauma film in the laboratory and recorded intrusive memories for one week using a diary. Gaze avoidance during trauma film exposure was associated with more intrusive memories. Greater attentional control over emotion prior to film viewing, as assessed with the experimental task, predicted fewer intrusive memories while self-reported attentional control was unrelated to intrusive memories. Preexisting capacity to shield information processing from distraction may protect individuals from developing intrusive emotional memories following exposure to stress or trauma. These findings provide important clues for prevention and intervention science.

Exploring memory function in earthquake trauma survivors with resting-state fMRI and machine learning

BACKGROUND

Traumatized earthquake survivors may develop poor memory function. Resting-state functional magnetic resonance imaging (rs-fMRI) and machine learning techniques may one day aid the clinical assessment of individual psychiatric patients. This study aims to use machine learning with Rs-fMRI from the perspectives of neurophysiology and neuroimaging to explore the association between it and the individual memory function of trauma survivors.

METHODS

Rs-fMRI data was acquired for eighty-nine survivors (male (33%), average age (SD):45.18(6.31) years) of Wenchuan earthquakes in 2008 each of whom was screened by experienced psychiatrists based on the clinician-administered post-traumatic stress disorder (PTSD) scale (CAPS), and their memory function scores were determined by the Wechsler Memory Scale-IV (WMS-IV). We explored which memory function scores were significantly associated with CAPS scores. Using simple multiple kernel learning (MKL), Rs-fMRI was used to predict the memory function scores that were associated with CAPS scores. A support vector machine (SVM) was also used to make classifications in trauma survivors with or without PTSD.

RESULTS

Spatial addition (SA), which is defined by spatial working memory function, was negatively correlated with the total CAPS score (r = - 0.22, P = 0.04). The use of simple MKL allowed quantitative association of SA scores with statistically significant accuracy (correlation = 0.28, P = 0.03; mean squared error = 8.36; P = 0.04). The left middle frontal gyrus and the left precuneus contributed the largest proportion to the simple MKL association frame. The SVM could not make a quantitative classification of diagnosis with statistically significant accuracy.

LIMITATIONS

The use of the cross-sectional study design after exposure to an earthquake and the leave-one-out cross-validation (LOOCV) increases the risk of overfitting.

CONCLUSION

Spontaneous brain activity of the left middle frontal gyrus and the left precuneus acquired by rs-fMRI may be a brain mechanism of visual working memory that is related to PTSD symptoms. Machine learning may be a useful tool in the identification of brain mechanisms of memory impairment in trauma survivors.

Exploring evidence of a dissociative subtype in PTSD: Baseline symptom structure, etiology, and treatment efficacy for those who dissociate

OBJECTIVE

With the inclusion of a dissociative subtype, recent changes to the DSM-5 diagnosis of posttraumatic stress disorder (PTSD) have emphasized the role of dissociation in the experience and treatment of the disorder. However, there is a lack of research exploring the clinical impact for highly dissociative groups receiving treatment for PTSD. The current study examined the presence and clinical impact of a dissociative subtype in a sample of individuals receiving treatment for chronic PTSD.

METHOD

This study used latent transition analyses (LTA), an expanded form of latent profile analyses (LPA), to examine latent profiles of PTSD and dissociation symptoms before and after treatment for individuals (N = 200) receiving prolonged exposure (PE) or sertraline treatment for chronic PTSD.

RESULTS

The best fitting LTA model was one with a 4-class solution at both pretreatment and posttreatment. There was a latent class at pretreatment with higher levels of dissociative symptoms. However, this class was also marked by higher reexperiencing symptoms, and membership was not predicted by chronic child abuse. Further, although those in the class were less likely to transition to the responder class overall, this was not the case for exposure-based treatment specifically.

CONCLUSION

These findings are not in line with the dissociative-subtype theoretical literature that proposes those who dissociate represent a clinically distinct group that may respond worse to exposure-based treatments for PTSD. (PsycINFO Database Record

Impact of stress response systems on forced choice recognition in an experimental trauma film paradigm

INTRODUCTION

Traumatic events are often followed by memory impairments of key features of the trauma. Stress hormones are involved in emotional memory formation. However, little is known about their influence during trauma on subsequent recognition memory.

MATERIAL AND METHODS

A pooled analysis of two double-blind, placebo-controlled studies (N = 175) was performed to assess the influence of the noradrenergic system and the hypothalamus-pituitaryadrenal (HPA) axis on intrusion formation. Participants received either 10 mg yohimbine (stimulating noradrenergic activity), 0.15 mg clonidine (inhibiting noradrenergic activity), or placebo (noradrenergic manipulation study) or 20 mg hydrocortisone or placebo (hydrocortisone manipulation study), each 60 min before watching a distressing film depicting severe sexual and physical violence. After seven days, the participants performed a 24-item forced choice recognition test. Memory was assessed for pre-, peri-, and post-trauma film scenes.

RESULTS

A significant film scene by intervention interaction indicated a differential influence of drug intervention on the number of correct pre-, peri-, and post-trauma film scene memories one week after the distressing film. Post hoc tests revealed that clonidine led to significantly fewer correct peri-trauma film scene memories compared to placebo and, on a trend level, to yohimbine.

DISCUSSION

Pharmacological inhibition of noradrenaline during a distressing film leads to impaired emotional recognition memory for the peri-trauma film scene.

The Human Interface of Biomedical Informatics

Biomedical informatics is the science of information, where information is defined as data with meaning. This definition identifies a fundamental challenge for informaticians: connecting with the healthcare team by enabling the acquisition, retrieval, and processing of information within the cognitive capabilities of the human brain. Informaticians can become aware of the constraints involved with cognitive processing and with workplace factors that impact how information is acquired and used to facilitate an improved user interface providing information to healthcare teams. Constraints affecting persons in the work environment include as follows: (1) cognitive processing of information; (2) cognitive load and memory capacity; (3) stress-affecting cognition; (4) cognitive distraction, attention, and multitasking; (5) cognitive bias and flexibility; (6) communication barriers; and (7) workplace environment. The human brain has a finite cognitive load capacity for processing new information. Short-term memory has limited throughput for processing of new informational items, while long-term memory supplies immediate simultaneous access to multiple informational items. Visual long-term memories can be extensive and detailed. Attention may be task dependent and highly variable among persons and requires maintaining control over distracting information. Multitasking reduces the effectiveness of working memory applied to each task. Transfer of information from person to person, or machine to person, is subject to cognitive bias and environmental stressors. High-stress levels increase emotional arousal to reduce memory formation and retrieval. The workplace environment can impact cognitive processes and stress, so maintaining civility augments cognitive abilities. Examples of human-computer interfaces employing principles of cognitive informatics inform design of systems to enhance the user interface.

The effects of state anxiety on analogue peritraumatic encoding and event memory: introducing the stressful event segmentation paradigm

Cognitive theories of PTSD argue that poor recall of trauma memories results from a stress-induced shift toward perceptual processing during encoding. The present study assessed the extent to which self-reported state anxiety affects event segmentation and its subsequent impact on memory performance (recall and recognition). Event segmentation is the cognitive process of condensing continuous streams of spatiotemporal information into discrete elements. In this study, undergraduates without PTSD used a computer programme to segment a stressful film and a non-stressful film and then they completed memory tasks for each film. For the stressful film, low memory performance was associated with high segmentation performance. A meditational analysis revealed high segmentation performance mediated a negative relationship between state anxiety and memory performance. Additionally, ad-hoc analyses suggest perceptual processing primarily drives segmentation of the stressful film and conceptual processing primarily drives segmentation of the non-stressful film.

Hypothesis: The Psychedelic Ayahuasca Heals Traumatic Memories via a Sigma 1 Receptor-Mediated Epigenetic-Mnemonic Process

Ayahuasca ingestion modulates brain activity, neurotransmission, gene expression and epigenetic regulation. N,N-Dimethyltryptamine (DMT, one of the alkaloids in Ayahuasca) activates sigma 1 receptor (SIGMAR1) and others. SIGMAR1 is a multi-faceted stress-responsive receptor which promotes cell survival, neuroprotection, neuroplasticity, and neuroimmunomodulation. Simultaneously, monoamine oxidase inhibitors (MAOIs) also present in Ayahuasca prevent the degradation of DMT. One peculiarity of SIGMAR1 activation and MAOI activity is the reversal of mnemonic deficits in pre-clinical models. Since traumatic memories in post-traumatic stress disorder (PTSD) are often characterised by “repression” and PTSD patients ingesting Ayahuasca report the retrieval of such memories, it cannot be excluded that DMT-mediated SIGMAR1 activation and the concomitant MAOIs effects during Ayahuasca ingestion might mediate such “anti-amnesic” process. Here I hypothesise that Ayahuasca, via hyperactivation of trauma and emotional memory-related centres, and via its concomitant SIGMAR1- and MAOIs- induced anti-amnesic effects, facilitates the retrieval of traumatic memories, in turn making them labile (destabilised). As Ayahuasca alkaloids enhance synaptic plasticity, increase neurogenesis and boost dopaminergic neurotransmission, and those processes are involved in memory reconsolidation and fear extinction, the fear response triggered by the memory can be reprogramed and/or extinguished. Subsequently, the memory is stored with this updated significance. To date, it is unclear if new memories replace, co-exist with or bypass old ones. Although the mechanisms involved in memory are still debated, they seem to require the involvement of cellular and molecular events, such as reorganisation of homo and heteroreceptor complexes at the synapse, synaptic plasticity, and epigenetic re-modulation of gene expression. Since SIGMAR1 mobilises synaptic receptor, boosts synaptic plasticity and modulates epigenetic processes, such effects might be involved in the reported healing of traumatic memories in PTSD patients. If this theory proves to be true, Ayahuasca could come to represent the only standing pharmacological treatment which targets traumatic memories in PTSD. Lastly, since SIGMAR1 activation triggers both epigenetic and immunomodulatory programmes, the mechanism here presented could help understanding and treating other conditions in which the cellular memory is dysregulated, such as cancer, diabetes, autoimmune and neurodegenerative pathologies and substance addiction.

The relationship between processing style, trauma memory processes, and the development of posttraumatic stress symptoms in children and adolescents

BACKGROUND AND OBJECTIVES

Data-driven processing, peri-event fear, and trauma memory characteristics are hypothesised to play a core role in the development of Posttraumatic Stress Disorder. We assessed the relationships between these characteristics and Posttraumatic Stress (PTS) symptoms in a sample of youth.

METHODS

Study 1 (N = 36, 7-16 years), involved a sample of children who had undergone a stressful orthopaedic procedure. One week later they answered a series of probed recall questions about the trauma (assessed for accuracy by comparison to a video) and reported on their PTS symptoms. They also rated confidence in their probed recall answers to assess meta-cognitive monitoring of their memory for the trauma. In Study 2, a sample of injured children (N = 57, 7-16 years) were assessed within 1-month of a visit to an Emergency Department, and then at 3-month follow-up. They answered probed recall questions, made confidence ratings, and completed measures of data-driven processing, peri-event fear, PTS and associated psychopathology. Memories were verified using witness accounts.

RESULTS

Studies 1 and 2 did not find an association between PTS symptoms and trauma memory accuracy or confidence. In Studies 1 and 2 data-driven processing predicted PTS symptoms.

LIMITATIONS

The studies had modest samples sizes and there were ceiling effects for some accuracy and confidence items.

CONCLUSIONS

Data-driven processing at the time of a trauma was associated with PTS symptoms after accounting for fear at the time of the trauma. Accuracy of recall for trauma memories was not significantly related to PTS symptoms. No decisive conclusion could be drawn regarding the relation between confidence in trauma memories and PTS symptoms.

Narrative fragmentation in child sexual abuse: The role of age and post-traumatic stress disorder

The present study aimed to assess the effects of age and PTSD on the narrative fragmentation in memories for child sexual abuse. Lexical complexity, cohesion and coherence were analyzed within a group of 86 allegations of children (M=10years; SD=3.7; range: 4-17) who were victims of sexual abuse. Results illustrated that age played an important role in establishing narrative coherence and predicted the level of orientation, the sequence of events and the level of evaluation of the event. Instead, PTSD was related to narrative coherence and cohesion. Therefore, in children, the narrative fragmentation could be an effective diagnostic tool for understanding the effects of PTSD. Moreover in a legal setting the traumatic effects of PTSD on the narrative coherence and cohesion could be significant indices in the evaluation of child testimony.

An empirical review of potential mediators and mechanisms of prolonged exposure therapy

Prolonged exposure (PE) is an empirically-supported treatment for posttraumatic stress disorder (PTSD), but the precise mechanism(s) by which PE promotes symptom change are not well established. Understanding how PE works is critical to improving clinical outcomes, advancing dissemination efforts, and enhancing transdiagnostic models of psychopathology. However, mechanisms research conducted in clinical treatment settings is complex, and findings may be difficult to interpret without appropriate context. This is the first review of potential mechanisms of PE to provide such context, by rigorously evaluating empirical findings in line with essential criteria for effective research on mechanisms (or mediators). We begin by describing six putative mechanisms identified by emotional processing theory and contemporary models of fear extinction, before thoroughly reviewing empirical findings from clinical research on PE and similar PTSD treatments. We provide a detailed description of each study and mechanism test, as well as ratings of strength of evidence and quality of evaluation based on a novel rating scheme. We highlight variables with strong evidence (belief change and between-session habituation), intermediate evidence (inhibitory learning and emotional engagement), and minimal support (narrative organization and within-session habituation). After discussing limitations of the extant literature and this review, we summarize specific challenges for research on PE mechanisms and highlight directions for future study based on clinical and research implications.

Experiences of therapeutic relationships on hospital wards, dissociation, and making connections

An interpretive phenomenological analysis sought to explore how people reporting moderate to high levels of dissociation experienced relationships with multidisciplinary hospital ward staff. Three superordinate themes were developed. First, the theme "multiple me and multiple them" explores the instability experienced by the participants as they managed their dissociative experiences alongside many inconsistencies. Second, "recognizing, meeting, or neglecting interpersonal and care needs" reflects on participants' needs within therapeutic relationships. Third, "between the needs of the internal system: navigating between 'better on my own' and 'someone to talk to'" discusses the confusion and understanding around dissociation and the importance of working with parts, not around them. Findings suggested that the current culture of some hospital wards directly influenced participants' distress, which could lead to further dissociation as a means of coping with perceived threats. Reflections on relational complexities and developing ward-based treatment are discussed.

Peritraumatic dissociation predicts posttraumatic stress disorder symptoms via dysfunctional trauma-related memory among war-affected children

Background: Among adults there is strong evidence about peritraumatic dissociation (PD) predicting posttraumatic stress disorder (PTSD), yet evidence among children is very limited. It has been suggested that disturbances in memory functioning might explain the association between PD and PTSD, but this has not yet been empirically tested. Objective: We aimed to test the hypotheses that greater PD would be associated with more posttraumatic stress disorder (PTSD) symptoms, and that some of this association would be mediated by disorganized and non-verbal memories about the traumatic event. Method: The sample included 197 Palestinian children (10-12-years) living in the Gaza Strip, participating in the aftermath of the 2008/9 war. Self-report questionnaires were used to measure PD (Peritraumatic Dissociative Experiences Questionnaire) three months post-war, as well as trauma-related memory (Trauma Memory Quality Questionnaire) and PTSD symptoms (Children's Revised Impact of Event Scale) six months later. Exposure to war trauma was assessed by a checklist. Structural equation modelling was used to examine direct and indirect paths from PD to posttraumatic PTSS, controlling for number of traumatic war events. Results: Structural equation modelling results showed that greater self-reported PD predicted higher levels of PTSS nine months post-war, and that a significant part, but not all, of this relationship was mediated via the quality of trauma-related memories. Conclusions: This study provided empirical evidence that, among war-affected children, greater PD during traumatic events is linked with higher levels of PTSD symptoms several months later, even when accounting for their personal exposure to war trauma. Further, the study supported the idea that the detrimental effects of dissociation during a traumatic event may be due to dysfunctional memories characterized by disorganization and lack of access to verbal and coherence. Further tests of these hypotheses with larger samples and more points of measurement are called for.

Post-traumatic stress symptoms in children and adolescents with chronic pain: A topical review of the literature and a proposed framework for future research

BACKGROUND AND OBJECTIVE

The co-occurrence of chronic pain and post-traumatic stress symptoms (PTSS) and post-traumatic stress disorder (PTSD) has gained increasing research attention. Studies on associations among pain and PTSS or PTSD in youth have largely been conducted in the context of acute injury or trauma. Less is known about the risk for co-occurrence with paediatric chronic pain. In this review, we (1) propose a conceptual framework to outline factors salient during childhood that may be associated with symptom severity, co-occurrence and mutual maintenance, (2) present relevant literature on PTSS in youth with acute and chronic pain and identify research gaps and (3) provide recommendations to guide paediatric research examining shared symptomatology.

DATABASES AND DATA TREATMENT

Electronic databases (PubMed and Google Scholar) were used to identify relevant articles using the search terms 'child, adolescent, paediatric, chronic pain, acute pain, post-traumatic stress symptoms and post-traumatic stress disorder'. Studies were retrieved and reviewed based on relevance to the topic.

RESULTS

Our findings revealed that existing biobehavioural and ecological models of paediatric chronic pain lack attention to traumatic events or the potential development of PTSS. Paediatric studies are also limited by lack of a conceptual framework for understanding the prevalence, risk and trajectories of PTSS in youth with chronic pain.

CONCLUSIONS

Our new developmentally informed framework highlights individual symptoms and shared contextual factors that are important when examining potential associations among paediatric chronic pain and PTSS. Future studies should consider bidirectional and mutually maintaining associations, which will be aided by prospective, longitudinal designs. WHAT DOES THIS REVIEW ADD?: This review presents relevant literature on pain and PTSS in youth and proposes a conceptual framework to examine factors salient during childhood that may be associated with symptom severity, comorbidity and mutual maintenance of chronic pain and PTSS in paediatric populations. We highlight dynamic factors that may change across children's development and provide recommendations to guide paediatric research examining potential associations among PTSS and chronic pain.

Sleep loss increases dissociation and affects memory for emotional stimuli

BACKGROUND AND OBJECTIVES

Because of their dreamlike character, authors have speculated about the role that the sleep-wake cycle plays in dissociative symptoms. We investigated whether sleep loss fuels dissociative symptoms and undermines cognitive efficiency, particularly memory functioning.

METHODS

Fifty-six healthy undergraduate students were randomly assigned to an experimental group (n = 28) and a control group (n = 28). The experimental group was deprived of sleep for 36 h in a sleep laboratory; the control group had a regular night of sleep. Sleepiness, mood, and dissociative symptoms were assessed 6 times in the experimental group (control group: 4 times). Several cognitive tasks were administered.

RESULTS

Sleep deprivation led to an increase in dissociative symptoms, which was mediated by levels of general distress. Feelings of sleepiness preceded an increase of dissociative symptoms and deterioration of mood. Finally, sleep loss also undermined memory of emotional material, especially in highly dissociative individuals.

LIMITATIONS

Limitations included moderate reliability of the mood scale, limited generalizability due to student sample, and a relatively short period of intensive sleep deprivation rather than lengthy but intermittent sleep loss, representative of a clinical population.

CONCLUSIONS

We found that sleep deprivation had significant effects on dissociation, sleepiness, and mood. Specifically, sleepiness and dissociation increased during the night, while mood deteriorated. Our findings stress the importance of sleep deficiencies in the development of dissociative symptoms. They support the view that sleep disruptions fuel distress, but also degrade memory and attentional control. It is against this background that dissociative symptoms may arise.

The DSM-5 dissociative-PTSD subtype: can levels of depression, anxiety, hostility, and sleeping difficulties differentiate between dissociative-PTSD and PTSD in rape and sexual assault victims?

The DSM-5 currently includes a dissociative-PTSD subtype within its nomenclature. Several studies have confirmed the dissociative-PTSD subtype in both American Veteran and American civilian samples. Studies have begun to assess specific factors which differentiate between dissociative vs. non-dissociative PTSD. The current study takes a novel approach to investigating the presence of a dissociative-PTSD subtype in its use of European victims of sexual assault and rape (N=351). Utilizing Latent Profile Analyses, we hypothesized that a discrete group of individuals would represent a dissociative-PTSD subtype. We additionally hypothesized that levels of depression, anger, hostility, and sleeping difficulties would differentiate dissociative-PTSD from a similarly severe form of PTSD in the absence of dissociation. Results concluded that there were four discrete groups termed baseline, moderate PTSD, high PTSD, and dissociative-PTSD. The dissociative-PTSD group encompassed 13.1% of the sample and evidenced significantly higher mean scores on measures of depression, anxiety, hostility, and sleeping difficulties. Implications are discussed in relation to both treatment planning and the newly published DSM-5.

Current status on behavioral and biological markers of PTSD: a search for clarity in a conflicting literature

Extensive research has identified stereotypic behavioral and biological abnormalities in post-traumatic stress disorder (PTSD), such as heightened autonomic activity, an exaggerated startle response, reduced basal cortisol levels and cognitive impairments. We have reviewed primary research in this area, noting that factors involved in the susceptibility and expression of PTSD symptoms are more complex and heterogeneous than is commonly stated, with extensive findings which are inconsistent with the stereotypic behavioral and biological profile of the PTSD patient. A thorough assessment of the literature indicates that interactions among myriad susceptibility factors, including social support, early life stress, sex, age, peri- and post-traumatic dissociation, cognitive appraisal of trauma, neuroendocrine abnormalities and gene polymorphisms, in conjunction with the inconsistent expression of the disorder across studies, confounds attempts to characterize PTSD as a monolithic disorder. Overall, our assessment of the literature addresses the great challenge in developing a behavioral and biomarker-based diagnosis of PTSD.

Dissociative mental states are canonically associated with decreased temporal theta activity on spectral analysis of EEG

Quantitative electroencephalographic (QEEG) changes relating to dissociative experiences have only rarely been demonstrated, and dissociative states were not quantified in those studies. The aim of this study was to explore concurrent associations between quantified dissociative states and QEEG spectral parameters, in particular theta activity, in psychiatric patients. Fifty psychiatric patients completed the State Scale of Dissociation (SSD) immediately after a 15-min EEG recording. The EEG was assessed by conventional clinical visual analysis as well as by quantitative (QEEG) spectral analysis. Canonical analysis was performed between the set of SSD subscale scores and the following QEEG parameters: alpha-theta magnitude ratios, and relative as well as absolute theta magnitude obtained from right and left mid- to posterior-temporal and parieto-occipital derivations. The SSD transferred well to the present data in terms of reliability and internal criterion-related validity. The SSD and Dissociative Experiences Scale (DES) correlated significantly (r = .73, p < .001). Conventional EEG analysis identified 29 EEGs (58%) as abnormal. The main abnormality in 23 EEGs was slowing, maximal temporally in half of these cases. Canonical analyses confirmed a statistically significant relationship between the dissociation variables (especially conversion and depersonalization symptoms) and the QEEG variables (especially relative theta magnitude in the temporal regions; R = .72, p = .03, for SSD-QEEG; and R = .66, p = .04, for DES-QEEG). Quantified dissociative mental states are positively canonically associated with decreased temporal theta activity and increased alpha-theta ratios on QEEG in psychiatric patients with a high tendency to dissociate. The potential implications of the dissociation-theta-alpha relationship for understanding normal attentional processes need to be studied further.