Can't get it out of my mind: A systematic review of predictors of intrusive memories of distressing events

The relationship between language features and PTSD symptoms: a systematic review and meta-analysis

Objective

The aim of this study is to investigate the relationship between language features and symptoms of Post-Traumatic Stress Disorder (PTSD) to determine if language features can serve as a reliable index for rapid screening and assessing PTSD.

Methods

A comprehensive literature search was performed using Pubmed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Ovid databases, augmented by backward reference tracking, to gather pertinent literature concerning language features and traumatic stress disorders published until August 2024.

Results

Twelve observational studies were included, comprising a cumulative sample size of 5,706 cases. Various language analysis tools, such as Linguistic Inquiry and Word Count (LIWC), manual coding, and machine learning techniques, were employed in the studies. Meta-analysis findings revealed a positive correlation between death-related words and PTSD symptoms (OR 1.32, 95%CI 1.10 to 1.59, I² 79.4%, p = 0.004), as well as significant positive correlations between negative emotion words and PTSD symptoms (OR 1.21, 95%CI 1.11 to 1.32, I² 30.5%, p < 0.001), anger-related words and PTSD symptoms (OR 1.14, 95%CI 1.11 to 1.17, I² 0.0%, p < 0.001), word count and PTSD symptoms (OR 1.20, 95%CI 1.09 to 1.31, I² 11.2%, p < 0.001). Additionally, a positive correlation was observed between body-related words and hyperarousal symptoms of PTSD (OR 1.26, 95%CI 1.15 to 1.37, I² 0.0%, p < 0.001), intrusive symptoms (OR 1.40, 95%CI 1.16 to 1.68, I² 0.0%, p < 0.001), and avoidance symptoms (OR1.29, 95%CI 1.21 to 1.37, I² 0.0%, p < 0.001). Death-related words (OR 1.16, 95% CI 1.08 to 1.25, I² 0.0%, p < 0.001) and word count (OR 1.18, 95% CI 1.10 to 1.27, I² 0.0%, p < 0.001) were observed positive correlations between intrusive symptoms of PTSD. Conversely, no correlation was found between the use of words related to sadness, anxiety, positive emotions, first-person pronouns, sensory, cognitive-related words and PTSD symptoms.

Conclusion

Death-related words, anger-related words, negative emotion words, body-related words and word count in Language features hold promise as a reliable indicator for rapid screening and assessing PTSD; however, further research is warranted to investigate their relationship with PTSD symptoms across various cultural contexts, genders, and types of trauma.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42024528621.

To be aware or not aware: Do intrusions with and without meta-awareness differ?

People sometimes re-experience traumatic events via intrusive memories that spontaneously and unintentionally intrude into consciousness (i.e., intrusions). Such intrusions can be experienced without explicit awareness (i.e., meta-awareness). However, we do not know whether intrusions with and without meta-awareness differ in how people experience them (i.e., characteristics) or react to them via maladaptive responses (i.e., suppression, negative interpretations), and therefore whether they are important to differentiate. To investigate this issue, we asked participants to watch a trauma analogue film and-during a subsequent unrelated reading task-intermittently probed them to capture and assess one film-related intrusion. Intrusion meta-awareness positively correlated with intrusion negativity, re-experiencing, and suppression, but not with how people interpreted the meaning of their intrusion. Our findings suggest intrusions with and without meta-awareness can differ in how they are experienced and associated with thought suppression-highlighting the importance of considering both types of intrusions in theory and practice.

Involuntary autobiographical memories as a transdiagnostic factor in mental disorders

Involuntary autobiographical memories are memories of personal events that come to mind with no preceding retrieval attempts. They have been studied broadly in autobiographical memory for decades and shown to be common and mostly positive in everyday life. Clinical literature has focused on negative intrusive memories of stressful events and tended to neglect other forms of involuntary autobiographical memories. However, recently, there has been an upsurge of research addressing involuntary memories more broadly in clinical disorders, including both stressful and mundane memories, and both real life events and simulated events. We here provide the first integrated and comprehensive review of all studied types of involuntary memories in clinical and subclinical populations. We review their frequencies and characteristics across a broad selection of memory properties. A systematic search of the PsycInfo, PubMed, and Web of Science databases yielded 79 empirical studies, with the majority focusing on depression, post-traumatic stress disorder, and psychosis, and a few addressing attention-deficit/hyperactivity disorder, bipolar disorder, eating disorders, health anxiety, obsessive-compulsive disorder, and social anxiety. Findings show that an increased frequency of involuntary memories-in all forms-is found across disorders, possibly reflecting executive deficits. Additionally, heightened negativity, greater emotional impact, and the use of maladaptive emotion regulation strategies in response to these memories are typically reported among individuals with PTSD and depression, but less consistently for psychotic disorders. Overall, the findings identify involuntary memories with distinct characteristics as a transdiagnostic phenomenon, suggesting a deeper understanding of mental health problems and more targeted treatment approaches.

What makes a trauma 'pathological'? - Perceived peritraumatic threat influences the development of intrusive memories

Intrusions are a hallmark symptom of posttraumatic stress disorder (PTSD). While dysfunctional cognitions are known posttraumatic contributors, peritraumatic processes are less understood. Perceived threat, alongside emotional factors, is theorized as significant, but experimental studies are lacking. Using the trauma film paradigm (TFP), we investigated peritraumatic threat's impact on intrusion development. Healthy participants (N = 93) viewed different distressing film clips (low, medium, high threat). Differences among the experimental groups were examined in the frequency and distress of intrusive memories, as well as distress and expectations. As hypothesized, the frequency of intrusive memories increased with increasing threat load, as did the distress and expectations related to intrusions. Fear elicited by film clips did not mediate this effect. Perceived threat is a crucial peritraumatic factor in intrusive memory formation, suggesting that a trauma perceived as highly threatening increases intrusion likelihood. Understanding traumatic factors influencing posttraumatic symptoms helps in targeting preventive interventions.

People experience similar intrusions about past and future autobiographical negative experiences

We know much about people's problematic reactions-such as distressing intrusions-to negative, stressful, or traumatic past events. But emerging evidence suggests people react similarly to negative and potentially-traumatic future events. Given similar processes underlie remembering the past and imagining the future more generally, we wondered how similar involuntary memories, or intrusions, are for experienced vs. anticipated events. We focused primarily on intrusions because they are a transdiagnostic reaction to traumatic events. We asked subjects to report either a very stressful event they had experienced in the past 6 months, or one they anticipated they could experience in the next 6 months. We measured the frequency of intrusions about these reported events, and intrusions' phenomenological characteristics (such as emotional intensity), negative appraisals about their meaning, and reactions to them more generally. Overall, we found intrusions about experienced vs. anticipated autobiographical events were similarly troubling. This pattern supports the idea that anticipating the future can be aversive and elicit post-traumatic-stress-like symptoms, just as remembering the past can. Our findings have implications for theoretical models of traumatic-stress and treatment of traumatic-stress symptoms.

Targeted memory reactivation during sleep improves emotional memory modulation following imagery rescripting

Targeted Memory Reactivation (TMR) during sleep benefits memory integration and consolidation. In this pre-registered study, we investigated the effects of TMR applied during non-rapid eye movement (NREM) sleep following modulation and updating of aversive autobiographical memories using imagery rescripting (ImR). During 2-5 nights postImR, 80 healthy participants were repeatedly presented with either idiosyncratic words from an ImR updated memory during sleep (experimental group) or with no or neutral words (control groups) using a wearable EEG device (Mobile Health Systems Lab-Sleepband, MHSL-SB) [1] implementing a close-loop cueing procedure. Multivariate analysis were conducted to assess change score trajectories in five key emotional memory characteristics (positive and negative valence, emotional distress, arousal, and vividness) across assessments (timepoints, t) and between the study groups (TMR condition). While ImR showed significant effects on all memory characteristics (d = 0.76-1.66), there were significant additional improvements in the experimental group. Memories were significantly less vivid and afflicted with less emotional distress and arousal following ImR-words cueing. TMR during sleep in individuals' homes was feasible and further improved some ImR's adaptive memory effects. If replicated in clinical samples, TMR may be utilized to augment the effects of ImR and other clinical memory modulation procedures and create personalized treatment options. Such advances in emotional memory treatments are direly needed, as aversive memories are a salient feature across mental disorders, such as post-traumatic stress disorder (PTSD).

Convergence of real-time and retrospective assessments: A systematic investigation of naturally occurring and experimentally induced intrusions

BACKGROUND AND OBJECTIVES

Ecological momentary assessment is a popular method for monitoring symptoms in real-time. Especially for fleeting experiences, such as intrusions, real-time assessments may be more accurate than retrospective estimates. However, there are concerns regarding reactivity effects associated with real-time assessments and, conversely, the reliance on bias-prone retrospective assessments in clinical science and practice. In this study we used a between-groups design to examine whether real-time intrusion assessments influence retrospective reports (aim 1). Then, we investigated whether real-time and retrospective assessments systematically differed within individuals (aim 2).

METHODS

Over two weeks, 150 non-clinical individuals provided weekly retrospective intrusion assessments, while the majority (n = 102) additionally reported their intrusions in real-time, via smartphones. We examined both naturally occurring intrusions, which individuals experience in their everyday lives, and intrusions related to a standardized stressor (i.e., Trier Social Stress Test), taking place halfway.

RESULTS

Using Bayesian statistics, we found that assessing intrusions in real-time did not convincingly affect retrospective reports, and there was no strong evidence that real-time and retrospective intrusion assessments differed. However, the evidence of absence was inconclusive for some measures. Real-time and retrospectively reported intrusion frequencies and distress were strongly associated with one another.

LIMITATIONS

Future research is advised to replicate these findings with larger samples, for other types of stressors, in clinical populations, and over extended assessment periods.

CONCLUSIONS

The general agreement between real-time and retrospective assessments of intrusions is encouraging, tentatively suggesting that researchers and clinicians can flexibly select the assessment method that best suits their objectives.

Does enhanced memory of disgust vs. fear images extend to involuntary memory?

People remember disgusting stimuli better than fearful stimuli, but do disgust's memory-enhancing effects extend to involuntary memory? This question is important because disgust reactions occur following trauma, and trauma-related involuntary memories are a hallmark of Posttraumatic Stress Disorder (PTSD) symptoms. In two experiments, we presented participants (n = 88 Experiment 1; n = 106 Experiment 2) with disgust, fear, and neutral images during an attention-monitoring task. Participants then completed an undemanding vigilance task, responding any time an image involuntarily came to mind. We measured the frequency and characteristics of these involuntary memories (e.g. emotional intensity) immediately after encoding and over a 24-hour delay (Experiment 2 only). Our main findings were mixed: participants experienced similarly frequent (Experiment 2) - or more (Experiment 1) - disgust as fear involuntary memories. Therefore, when controlling for memory-enhancing confounds (e.g. distinctiveness), in-laboratory disgust memory enhancement does not extend to involuntary memory. Disgust memories were more emotionally intense than fear memories over the 24-hour delay- but not immediately after encoding - suggesting disgust elicits additional consolidation processes to fear. Participants paid more attention towards the disgust images, but the attention did not account for the memory of disgust. In sum, disgust and fear have both similar and distinct cognitive effects.

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.

Self-reported sensibility to bodily signals predicts individual differences in autobiographical memory: an exploratory study

Recent theoretical perspectives have advanced that autobiographical memory processes are supported by interoception, the perception of internal bodily sensations. Yet, this relationship remains largely underexplored. The present study addressed this critical gap in the literature by systematically investigating the association between self-reported Interoceptive Sensibility and various individual differences measures of autobiographical memory. In Study 1, using a correlational approach in a large sample of participants (N = 247), we identified significant correlations between standardised measures of interoception and the general experience of autobiographical memory and the frequency of involuntary mental time travel. These associations remained significant even after controlling for potential confounding factors in terms of age, gender, and trait affectivity, underscoring their robustness. Study 2 replicated and extended the associations identified in Study 1 in another large participant sample (N = 257), further validating them by accounting for the potential confounding effect of well-being. Our findings demonstrate that individuals' ability to perceive and understand bodily signals robustly relates to how they experience autobiographical memories. By adopting an exploratory approach based on individual differences, our results provide novel and concrete insights into the association between interoception and autobiographical memory, providing a strong foundation for future investigations into the causal mechanisms connecting these two constructs.

Cumulative Trauma Exposure and Post-Traumatic Stress Symptoms among Older Adults in South Africa: Does Post-Traumatic Growth Moderate this Link?

The study explored the interplay between PTG and PTSS in older South African adults exposed to trauma. A quantitative cross-sectional design was employed. 195 participants from a low-resourced setting in South Africa were interviewed using the UCLA Life Adversities Screener, the PTSD Checklist (DSM-5), and the PTG-Inventory. Hayes Model SPSS Macro PROCESS for moderation was used. Overall, the relationship between cumulative trauma exposure and PTSS was moderated by the PTG level (b = -0.09, SE = 0.04, p = .0113). The findings suggest that cumulative trauma exposure is a significant predictor of PTSS, and the relationship is moderated by the threshold level of PTG. Higher levels of PTG mitigated the effect of cumulative trauma exposure on PTSS.

Neural signatures of default mode network subsystems in first-episode, drug-naive patients with major depressive disorder after 6-week thought induction psychotherapy treatment

Evidence indicates that the default mode network (DMN) plays a crucial role in the neuropathology of major depressive disorder (MDD). However, the neural signatures of DMN subsystems in MDD after low resistance Thought Induction Psychotherapy (TIP) remain incompletely understood. We collected functional magnetic resonance imaging data from 20 first-episode, drug-naive MDD and 20 healthy controls (HCs). The DMN was segmented into three subsystems and seed-based functional connectivity (FC) was computed. After 6-week treatment, the significantly reduced FCs with the medial temporal lobe memory subsystem in MDD at baseline were enhanced and were comparable to that in HCs. Changed Hamilton Depression Rating Scale scores were significantly related with changed FC between the posterior cingulate cortex (PCC) and the right precuneus (PCUN). Further, changed serotonin 5-hydroxytryptamine levels were significantly correlated with changed FCs between the PCC and the left PCUN, between the posterior inferior parietal lobule and the left inferior temporal gyrus, and between the retrosplenial cortex and the right inferior frontal gyrus, opercular part. Finally, the support vector machine obtained an accuracy of 67.5% to distinguish between MDD at baseline and HCs. These findings may deepen our understanding of the neural basis of the effects of TIP on DMN subsystems in MDD.

From pregnancy to the postpartum: Unraveling the complexities of symptom profiles among trauma-exposed women

BACKGROUND

Many women experience new onset or worsening of existing posttraumatic stress disorder (PTSD) symptoms during pregnancy and the early postpartum period. However, perinatal PTSD symptom profiles and their predictors are not well understood.

METHODS

Participants (N = 614 community adults) completed self-report measures across three methodologically similar longitudinal studies. Mixture modeling was used to identify latent subgroups of trauma-exposed women with distinct patterns of symptoms at pregnancy, 1-month, and 3-month postpartum.

RESULTS

Mixture modeling demonstrated two classes of women with relatively homogenous profiles (i.e., low vs. high symptoms) during pregnancy (n = 237). At 1-month postpartum (n = 391), results suggested a five-class solution: low symptoms, PTSD only, depression with primary appetite loss, depression, and comorbid PTSD and depression. At 3-months postpartum (n = 488), three classes were identified: low symptoms, elevated symptoms, and primary PTSD. Greater degree of exposure to interpersonal trauma and reproductive trauma, younger age, and minoritized racial/ethnic identity were associated with increased risk for elevated symptoms across the perinatal period.

LIMITATIONS

Only a subset of potential predictors of PTSD symptoms were examined. Replication with a larger and more racially and ethnically diverse sample of pregnant women is needed.

CONCLUSIONS

Results highlight limitations of current perinatal mental health screening practices, which could overlook women with elevations in symptoms (e.g., intrusions) that are not routinely assessed relative to others (e.g., depressed mood), and identify important risk factors for perinatal PTSD symptoms to inform screening and referral.

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.

Using experience sampling methodology (ESM) to improve our understanding of day-to-day intrusion frequency and related distress in survivors of trauma

BACKGROUND AND OBJECTIVES

Cognitive models of posttraumatic stress disorder (PTSD) suggest that appraisals of traumatic sequelae and subsequent distress drive the development and maintenance of PTSD. Posttraumatic research has relied heavily on macro-longitudinal designs, with weeks or months between assessments of trauma-related cognitions and symptoms. The present study uses experience sampling methodology (ESM) better understand the day-to-day experiences of trauma exposed individuals.

METHODS

One-hundred trauma exposed adults reported their posttraumatic symptoms, interpretations, and behaviours four times a day over a 10-day ESM period.

RESULTS

As anticipated, within-person fluctuations in negative appraisals of intrusions and maladaptive coping strategies (e.g., thought suppression) were significantly positively associated with intrusion frequency and related distress. In all cases, the associations for negative appraisals and maladaptive coping were stronger with intrusion related distress than intrusion frequency.

LIMITATIONS

The observed contemporaneous associations only demonstrate that variables reliably fluctuated together and cannot indicate causality.

CONCLUSIONS

The findings demonstrate that day-to-day fluctuations in trauma related perceptions and sequelae are significant and should be explored alongside broader individual differences to advance our understanding of the development, maintenance, and treatment of PTSD.

Mental threat rehearsal increases fear generalization

BACKGROUND AND OBJECTIVES

Fear generalization to harmless stimuli characterizes anxiety-related disorders, but much remains unknown about its determinants. Based on studies showing that mental imagery of threat can increase conditioned fear responding, we tested whether it also facilitates fear generalization, and whether threat inflation moderates this effect.

METHODS

In a fear conditioning study, 120 participants first completed an acquisition phase, in which one of two pictures was followed by an aversive sound (human scream). Then, the sound was presented 11 times at an increasing (threat inflation) or constant volume (no threat inflation). Finally, a generalization stimulus was presented, and some participants were asked to imagine the last sound (threat rehearsal) and others were not (no threat rehearsal).

RESULTS

Bayesian informative hypotheses tests indicated that imagery-based threat rehearsal increased generalization of threat expectancy, and, combined with threat inflation, it also resulted in stronger generalized distress.

LIMITATIONS

due to the absence of a test phase, it is unclear whether our effects would transfer to other GSs and whether they would persist beyond the manipulation phase.

CONCLUSIONS

Mental imagery of threat may put individuals at risk for fear generalization. Future studies should examine whether modulating imagery may prevent clinical anxiety.

Disentangling boredom from depression using the phenomenology and content of involuntary autobiographical memories

Recurrent involuntary autobiographical memories (IAMs) are memories retrieved unintentionally and repetitively. We examined whether the phenomenology and content of recurrent IAMs could differentiate boredom and depression, both of which are characterized by affective dysregulation and spontaneous thought. Participants (n = 2484) described their most frequent IAM and rated its phenomenological properties (e.g., valence). Structural topic modeling, a method of unsupervised machine learning, identified coherent content within the described memories. Boredom proneness was positively correlated with depressive symptoms, and both boredom proneness and depressive symptoms were correlated with more negative recurrent IAMs. Boredom proneness predicted less vivid recurrent IAMs, whereas depressive symptoms predicted more vivid, negative, and emotionally intense ones. Memory content also diverged: topics such as relationship conflicts were positively predicted by depressive symptoms, but negatively predicted by boredom proneness. Phenomenology and content in recurrent IAMs can effectively disambiguate boredom proneness from depressive symptoms in a large sample of undergraduate students from a racially diverse university.

An investigation of the mechanisms underlying the link between abstract reasoning and intrusive memories: A trauma analogue study

Potentially traumatic events elicit intrusive memories to which some individuals are more vulnerable than others. Lower abstract reasoning capacity has been related to more intrusive memories. A more perceptual processing style when encoding the event may mediate this link. Another potential mechanism is lower attentional control, resulting in greater attentional bias toward trauma-related content. We examined both of these possibilities using a trauma-analogue paradigm. One hundred and twenty participants completed abstract reasoning tasks. Then, 90 participants watched a negative video, and 30 participants watched a neutral video. The level of perceptual processing (P1) and attentional bias (RT) towards trauma-related stimuli were measured with a pictorial Stroop task while recording EEG. Intrusive memories were recorded for 5 days. Abstract reasoning was not associated with intrusive memories. However, lower abstract reasoning tended to be associated with more perceptual processing (greater P1 amplitude) following the negative video. More perceptual processing also tended to be related to more intrusive memories for younger participants. A more pronounced attentional bias was related to more intrusive memories, but only for women. Unexpectedly, also for women, better verbal reasoning was linked to a more pronounced attentional bias. Results are compared to existing studies and future implications are discussed.

Examining the role of trait anxiety and attentional bias to negative information in intrusion vulnerability following an emotionally negative event

BACKGROUND AND OBJECTIVES

Research shows that individuals with heightened trait anxiety are more likely to experience intrusions; however, the mechanism that accounts for this relationship is unclear. Two alternative hypotheses were tested to determine the nature of the associations between trait anxiety, attentional bias to negative information, and intrusion vulnerability.

METHODS

Intrusions were elicited using the trauma film paradigm, and post-event attentional bias to negative information was assessed using the dot-probe task. Participants then completed a week-long intrusions diary.

RESULTS

Results showed that attentional bias to negative information mediated the effect of heightened trait anxiety on elevated intrusion frequency. It was also revealed that heightened trait anxiety was associated with elevated intrusion-related distress, though attentional bias to negative information did not mediate this relationship.

LIMITATIONS

Our sample was comprised of undergraduate students who were not selected based on a previous pathology. Replication in clinical samples is warranted.

CONCLUSIONS

These findings provide new insight regarding individual differences in the experience of intrusions and suggest that both the frequency and distress associated with intrusions could represent clinical targets.

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-based autobiographical memory interventions for PTSD: a meta-analysis of randomized controlled trials

Introduction

The aim of this systematic review and meta-analysis is to evaluate the efficacy of narrative-based interventions (NBIs) for individuals with post-traumatic stress disorder (PTSD). Investigating the efficacy of NBIs should yield insight on autobiographical memory (AM) phenomena implicated in PTSD onset and recovery, leading to improved intervention protocols. Furthermore, by analyzing how NBIs influence maladaptive AM distortions, we hope to shed light on the theorized narrative architecture of AM more generally.

Methods

A systematic literature search was conducted according to PRISMA and Cochrane guidelines in MEDLINE, EMBASE, PsychINFO, and PubMed. Additional studies were then also identified from the reference lists of other relevant literature and considered for inclusion. Studies were then evaluated for adherence to the inclusion/exclusion criteria and assessed for risk of bias. Various meta-analyses were performed on included studies to understand how NBIs may or may not influence the overall effect size of treatment.

Results

The results of the meta-analysis of 35 studies, involving 2,596 participants, suggest that NBIs are a viable and effective treatment option for PTSD, yielding a statistically significant within-group effect size and decrease in PTSD symptomatology at both post-treatment [g = 1.73, 95% CI (1.23-2.22)] and 3-9 month follow-up assessments [g = 2.33, 95% CI (1.41-3.26)]. Furthermore, the difference in effect sizes between NBIs compared to active and waitlist controls was statistically significant, suggesting that NBIs are superior. Sub-analyses showed that NET provided a stronger effect size than FORNET, which may be due to the nature of the traumatic event itself and not the treatment protocol. While evidence of small study and publication bias was present, a weight-function model and trim-and-fill method suggested it was not influencing the overall results.

Discussion

This meta-analysis presents strong evidence supporting the use of NBIs in the treatment of PTSD. Clear similarities can be identified between NBIs included in this analysis that make them distinct from non-NBI interventions, which are reviewed in the discussion. Controlled comparisons between NBIs and non-NBIs would help to further understand AM mechanisms of action implicated in recovery and how various interventions facilitate them. Future research should also aim to elucidate the full range of AM impairment in individuals with PTSD to gain insight on how other memory capabilities, such as the ability to mentally simulate the future, are implicated in the pathogenesis of PTSD.

Exposure to continuous political violence: rational and experiential thinking styles, coping styles and post traumatic stress symptoms

Cognitive style is considered an important determinant of individual behavior. The aim of the present study was to examine the relations between rational and experiential thinking styles, coping styles and Post Traumatic Stress (PTS) symptoms among civilians exposed to continuous and ongoing exposure to political violence. Three-hundred and thirty-two Israeli adult citizens living in the south region of Israel reported on their experiences of exposure to political violence as well as level of PTS, coping styles, and preference toward rational and experiential processing style. Results showed that low rational thinking was related with elevated PTS, both directly and indirectly through the mediation of high emotion-focused coping. The findings suggest that rational thinking may serve as a protective factor against stress related to chronic exposure to political violence; conversely, a preference for low rationality may be a risk factor.

Investigating features that contribute to evaluations of intrusiveness for thoughts and memories

What makes a thought feel intrusive? One possibility is that traumatic experiences are the primary cause of intrusive thoughts and memories. Another possibility is that experiences of intrusiveness arise from the features involved with re-experiencing. We investigated several features that may lead a thought to feel intrusive: task-congruence, repetition, and affective content. In Experiment 1, participants listened to popular song clips expected to become stuck in one's head. In Experiment 2, participants were cued to recall their own autobiographical memories. We found that both songs and autobiographical memories replaying mentally felt more intrusive when they were incongruent with the current task, cued repeatedly, and had negative emotional content. Additionally, even liked songs and positive autobiographical memories were evaluated as highly intrusive under some conditions. Based on these findings, we argue that intrusiveness is not limited to traumatic thoughts, but rather is a context-dependent evaluation influenced by a variety of features.

Disgust and fear reactions uniquely affect intrusions and posttraumatic stress symptoms

Disgust reactions commonly occur during/following trauma and predict posttraumatic stress (PTS) symptoms. Yet, disgust is not mentioned in DSM-5 PTSD criteria. To investigate disgust's clinical significance in PTSD, we measured the relationship between disgust (and fear) reactions to a personal trauma, and problematic intrusion characteristics (e.g., distress) and intrusion symptom severity. We focused on intrusions because they are a transdiagnostic PTSD symptom, though we also measured overall PTS symptoms to replicate prior work. Participants (N = 471) recalled their most traumatic/stressful event from the past six months. They then rated disgust and fear reactions to this event and completed the Posttraumatic Stress Disorder Checklist-5. Participants who had experienced intrusions about their event in the past month (n = 261) rated these intrusions on several characteristics (e.g., distress, vividness). We found stronger traumatic event-related disgust reactions were associated with more problematic intrusion characteristics, higher intrusion symptom severity, and higher overall PTS symptom severity. Notably, disgust reactions uniquely predicted these variables after statistically controlling for fear reactions. We conclude disgust reactions to trauma may be similarly pathological to fear reactions for intrusion and broader PTS symptoms. Therefore, PTSD diagnostic manuals and treatments should recognize disgust as a trauma-relevant emotion.

Posttraumatic Stress Symptoms and its Association with Rumination, Thought Suppression and Experiential Avoidance: a Systematic Review and Meta-Analysis

Posttraumatic stress disorder (PTSD) is a severe mental disorder causing high individual and societal costs. The use of maladaptive emotion regulation (ER) strategies has been identified as a potential contributing factor. This meta-analysis aimed to quantify the associations between PTSD symptoms and rumination, thought suppression and experiential avoidance. The systematic literature search resulted in 5574 studies, 75 of which were included in the analysis. From those eligible studies 189 effect sizes were obtained. For symptoms of posttraumatic stress, large effects were found for associations with rumination (r = .52) and experiential avoidance (r = .48), whereas a medium effect size was found for thought suppression (r = .29). With respect to different PTSD symptom clusters, associations ranged between r = .35 and r = .41 for associations with intrusive re-experiencing, between r = .39 and r = .41 for associations with avoidance, between r = .50 and r = .53 for associations with alterations in cognitions and mood and between r = .41 and r = .45 for associations with alterations in arousal and activity. Few available studies provide some evidence that associations might be somewhat reduced but still substantial in longitudinal compared to cross-sectional studies. These findings provide valuable targets for future investigations with the long-term goal of improving targeted interventions for the prevention and treatment of PTSD symptoms.

Oxytocin vs. placebo effects on intrusive memory consolidation using a trauma film paradigm: a randomized, controlled experimental study in healthy women

Oxytocin administration during a trauma analogue has been shown to increase intrusive memories, which are a core symptom of post-traumatic stress disorder (PTSD). However, it is unknown whether oxytocin influences the acquisition or the consolidation of the trauma. The current study investigates the effect of the activation of the oxytocin system during the consolidation of an analogue trauma on the formation of intrusive memories over four consecutive days and whether this effect is influenced by individual neurobiological, genetic, or psychological factors. We conducted a randomized double-blind placebo-controlled study in 217 healthy women. They received either a single dose of intranasal oxytocin (24 IU) or placebo after exposure to a trauma film paradigm, which reliably induces intrusive memories. We used a general random forest to examine a potential heterogeneous treatment effect of oxytocin on the consolidation of intrusive memories. Furthermore, we used a poisson regression to examine whether salivary alpha amylase activity (sAA) as a marker of noradrenergic activity and cortisol response to the film, polygenic risk score (PRS) for psychiatric disorders, and psychological factors influence the number of intrusive memories. We found no significant effect of oxytocin on the formation of intrusive memories (F(2, 543.16) = 0.75, p = 0.51, ηp2 = 0.00) and identified no heterogeneous treatment effect. We replicated previous associations of the PRS for PTSD, sAA and the cortisol response on intrusive memories. We further found a positive association between high trait anxiety and intrusive memories, and a negative association between the emotion regulation strategy reappraisal and intrusive memories. Data of the present study suggest that the consolidation of intrusive memories in women is modulated by genetic, neurobiological and psychological factors, but is not influenced by oxytocin. Trial registration: NCT03875391.

Effects of comorbid posttraumatic stress disorder on cognitive dysfunction in Chinese male methamphetamine patients

OBJECTIVES

Cognitive dysfunction and posttraumatic stress disorder (PTSD) are common in methamphetamine patients. However, few studies have investigated the cognitive performance of methamphetamine patients with PTSD. The purpose of this study was to investigate the impact of comorbid PTSD on cognitive function in Chinese male methamphetamine patients.

METHODS

We analyzed 464 methamphetamine patients and 156 healthy volunteers. The PTSD Screening Scale (PCL-5) was used to assess PTSD and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess cognitive function.

RESULTS

Compared with healthy controls, methamphetamine patients had more cognitive dysfunction in immediate memory, visuospatial/constructional, language, attention and delayed memory. Moreover, methamphetamine patients with PTSD had less cognitive dysfunction in immediate memory, attention, and delayed memory than methamphetamine patients without PTSD. Further stepwise regression analysis showed that PTSD alterations in arousal and reactivity cluster were risk predictors for language, and PTSD negative alteration in cognition and mood cluster were risk predictors for delayed memory.

CONCLUSIONS

Our results indicate that methamphetamine patients without PTSD have poorer cognitive dysfunction than those with PTSD. Some demographic and PTSD symptom clusters are protective or risk factors for cognitive dysfunction in methamphetamine patients.

Machine learning to detect invalid text responses: Validation and comparison to existing detection methods

A crucial step in analysing text data is the detection and removal of invalid texts (e.g., texts with meaningless or irrelevant content). To date, research topics that rely heavily on analysis of text data, such as autobiographical memory, have lacked methods of detecting invalid texts that are both effective and practical. Although researchers have suggested many data quality indicators that might identify invalid responses (e.g., response time, character/word count), few of these methods have been empirically validated with text responses. In the current study, we propose and implement a supervised machine learning approach that can mimic the accuracy of human coding, but without the need to hand-code entire text datasets. Our approach (a) trains, validates, and tests on a subset of texts manually labelled as valid or invalid, (b) calculates performance metrics to help select the best model, and (c) predicts whether unlabelled texts are valid or invalid based on the text alone. Model validation and evaluation using autobiographical memory texts indicated that machine learning accurately detected invalid texts with performance near human coding, significantly outperforming existing data quality indicators. Our openly available code and instructions enable new methods of improving data quality for researchers using text as data.

Treatment of adjustment disorder stemming from romantic betrayal using memory reactivation under propranolol: A open-label interrupted time series trial

OBJECTIVES

In a sustained relationship, romantic betrayal is a catastrophic event that can precipitate an adjustment disorder (AD). Surprisingly, there exists no empirically validated treatment for AD, despite its high prevalence in clinical practice. Considering the promise of memory reactivation under propranolol (i.e., reconsolidation interference) for treating posttraumatic stress disorder, we sought to extend this finding to AD, given that in both disorders, symptoms stem from an identified stressor.

METHOD

A single-blind interrupted time series design was used to examine the efficacy of memory reactivation under propranolol to alleviate symptoms of AD. After being placed on a 4-week waitlist, sixty-one participants received 5 weekly 25-min treatments during which they recalled the betrayal event, 1 h after having orally ingested the beta-blocker propranolol.

RESULTS

Segmented regression analyses on the intent-to-treat sample revealed that AD symptoms significantly decreased during the treatment phase (pre/post Cohen's d = 1.44), compared to the waitlist phase (d = 0.01). Significant pre/post reductions in anxio-depressive symptomatology were also found. Improvement was maintained at the 4-month follow-up on all outcomes.

CONCLUSION

Memory reactivation under propranolol shows promise in reducing symptoms of AD. This study provides the theoretical framework and necessary effect sizes to inform larger, double-blind, placebo-controlled clinical trials.

Are involuntary autobiographical memory and déjà vu natural products of memory retrieval?

Involuntary autobiographical memories (IAMs) and déjà vu are phenomena that occur spontaneously in daily life. IAMs are recollections of the personal past, whereas déjà vu is defined as an experience in which the person feels familiarity at the same time as knowing that the familiarity is false. We present and discuss the idea that both IAMs and déjà vu can be explained as natural phenomena resulting from memory processing and, importantly, are both based on the same memory retrieval processes. Briefly, we hypothesise that both can be described as "involuntary" or spontaneous cognitions, where IAMs deliver content and déjà vu delivers only the feeling of retrieval. We map out the similarities and differences between the two, making a theoretical and neuroscientific account for their integration into models of memory retrieval and how the autobiographical memory literature can explain these quirks of daily life and unusual but meaningful phenomena. We explain the emergence of the déjà vu phenomenon by relating it to well-known mechanisms of autobiographical memory retrieval, concluding that IAMs and déjà vu lie on a continuum.

Estradiol during (analogue-)trauma: Risk- or protective factor for intrusive re-experiencing?

Intrusions, a key symptom of posttraumatic stress disorder (PTSD), can occur in the form of images but also as pain sensations. Similar to audiovisual intrusions, the frequency and persistence of pain intrusions varies greatly between individuals. In the current study, we examined whether peritraumatic circulating 17β-estradiol (E2) levels are a biologic factor associated with subsequent audiovisual (i.e., film) and pain intrusion development, and whether peritraumatic stress levels modulate this relationship. Forty-one free-cycling women participated in an ecologically informed trauma-pain-conditioning (TPC) paradigm, using trauma-films and pain as unconditioned stimuli. Independent variables were salivary peritraumatic E2 levels and stress indexed by salivary cortisol and self-reported state-anxiety during TPC. Outcomes were film- and pain-intrusions occurring during daily-life in the week following TPC and a Memory-Triggering-Task in response to conditioned stimuli 24 h after TPC. In the week after analogue-trauma, higher peritraumatic E2 levels were associated with a greater probability of experiencing film-intrusions in the beginning of the week, which switched to a lower probability toward the end of the week. This time-dependent relationship between E2 and film-intrusions only held for higher state-anxious women. In contrast, results indicated a consistent inverse relationship between peritraumatic E2 levels and pain-intrusions during daily-life and Memory-Triggering-Task. Together, these data suggest that higher peritraumatic E2 levels could be associated with lower long-term visual trauma intrusions, as well as lower pain-intrusions, and thereby possibly constitute a protective biologic factor for PTSD and potentially also for chronic pain.

Narrative thinking lingers in spontaneous thought

Some experiences linger in mind, spontaneously returning to our thoughts for minutes after their conclusion. Other experiences fall out of mind immediately. It remains unclear why. We hypothesize that an input is more likely to persist in our thoughts when it has been deeply processed: when we have extracted its situational meaning rather than its physical properties or low-level semantics. Here, participants read sequences of words with different levels of coherence (word-, sentence-, or narrative-level). We probe participants’ spontaneous thoughts via free word association, before and after reading. By measuring lingering subjectively (via self-report) and objectively (via changes in free association content), we find that information lingers when it is coherent at the narrative level. Furthermore, and an individual’s feeling of transportation into reading material predicts lingering better than the material’s objective coherence. Thus, our thoughts in the present moment echo prior experiences that have been incorporated into deeper, narrative forms of thinking.

Some experiences linger in our minds, while others quickly fade. Here, the authors show that the extent to which our recent experiences linger into subsequent thought increases as a function of processing depth.

Sex hormones and cortisol during experimental trauma memory consolidation: Prospective association with intrusive memories

Background Trauma- and stress-related disorders, such as post-traumatic stress disorder (PTSD), are more common in females than in males. Sex hormones affect learning and emotional memory formation and may be associated with the development of PTSD. Most previous studies have indexed these hormones in isolation. Objectives: To investigate associations of sex hormones and cortisol during memory consolidation on the development of intrusive memories. Methods: We employed an experimental trauma film paradigm in 61 healthy women and indexed salivary testosterone, progesterone, estradiol, and cortisol on day one and day two post experimental trauma exposure and their effects on intrusion frequency, distress, and vividness. Intrusive trauma memories were indexed by means of a diary in which participants documented intrusion frequency, distress, and vividness. Results and conclusion: Participants reported an average of 5.3 intrusions over the course of seven days (SD = 4.6, range 0-26). Progesterone, and estradiol indexed on day one predicted intrusion frequency, with higher progesterone and lower estradiol predicting more intrusive memories (p-values AUC progesterone 0.01 and estradiol 0.02). There was no evidence for associations between hormone concentration indices on day two and intrusion outcomes. Further research on the roles of gonadal and adrenal hormones in trauma memory formation is needed to advance our efforts to understand their influence on PTSD development.

Neuroscientific evidence for pain being a classically conditioned response to trauma- and pain-related cues in humans

ABSTRACT

Psychological trauma is typically accompanied by physical pain, and posttraumatic stress disorder (PTSD) often co-occurs with chronic pain. Clinical reports suggest that pain after trauma may be part of a re-experiencing symptomatology. Classical conditioning can underlie visual re-experiencing since intrusions can occur as conditioned responses (CRs) to trauma-related cues. If individuals also experience pain to cues previously paired with, but not anymore inflicting nociceptive stimulation (CSs), conditioning could also explain re-experiencing of pain. Sixty-five participants underwent classical conditioning, where painful electrocutaneous stimulation and aversive film-clips served as unconditioned stimuli (USs) in a 2(pain/no pain)×2(aversive/neutral film) design. CSs were neutral pictures depicting contextual details from the films. One day later, participants were re-exposed to CSs during a memory-triggering-task (MTT). We assessed pain-CRs by self-report and an fMRI-based marker of nociceptive pain, the neurologic pain signature (NPS); and recorded spontaneous daily-life pain-intrusions with an e-diary. During conditioning, pain-signaling CSs elicited more self-reported-pain and NPS-responses than no-pain-signaling CSs. Possibly because the aversive-film masked differences in participants' responses to pain-signaling vs. no-pain-signaling CSs, pain-CRs during acquisition only emerged within the neutral-film condition. When participants were re-exposed to CSs during MTT, self-reported-pain-CRs during the neutral-film condition and, though more uncertain, NPS-CRs during the aversive-film condition persisted. Importantly, participants with stronger pain-CRs showed a greater probability and severity of experiencing spontaneous pain intrusions during daily-life. Our data support that pain can emerge as a CR with emotional and sensory components. Classical conditioning presents a possible mechanism explaining pain-intrusions, and more broadly, pain experienced without nociceptive input.

Emotional autobiographical memory impairment features in three mental disorders

We proposed the Emotional Autobiographical Memory Test (EAMT) as a specialized method for measuring emotional autobiographical memory impairment in patients with mental disorders. The EAMT was tested with 32 patients with schizophrenia, 18 patients with bipolar disorder, 32 patients with depression, and 42 people undiagnosed with such disorders. We extracted 13 indices of five kinds of features from participants' emotional autobiographical memory and compared them among the four groups. The overgeneralization result in the schizophrenia and depression groups was consistent with previous results, supporting the EAMT's validity. However, inconsistent with previous results, overgeneralization was not found in the bipolar disorder group. Further, the count of involuntary memories in the patient groups (vs. control group) was significantly smaller, which can guide future researchers in investigating the psychopathology of mental disorders.

How Expectations Shape the Formation of Intrusive Memories: An Experimental Study Using the Trauma Film Paradigm

Background

Although intrusions are the hallmark symptom of posttraumatic stress disorder, there is still limited knowledge about the processes that contribute to the development of intrusions. Here, we used the well-established trauma film paradigm (TFP) to investigate how expectations about the intensity and controllability of intrusions influence their occurrence.

Methods

90 healthy participants underwent the TFP before they were randomized to one of three conditions manipulating their expectations about intrusions: positive expectations group; negative expectations group; control group. The primary outcome was the frequency and severity of intrusive memories as assessed with an intrusion diary over seven days.

Results

The TFP was well implemented, as indicated by significant post-film anxiety and a substantial number of intrusions reported for the subsequent week. The three groups did not differ in their expectations about intrusions and, relatedly, in their experience of intrusions. A mediation analysis revealed that the influence of post-film anxiety on intrusive memories was fully mediated by expectations.

Conclusions

Despite the failure of the expectation manipulation, the results of the mediation analysis support the hypothesis that post-film expectations influence the formation of intrusive memories, suggesting that intrusions may result from maladaptive dynamics between emotional and cognitive processes following trauma(like) experiences.

Specifying the Relations among PTSD Symptom Clusters and Parenting Stress in Mothers Engaged in Substance Use Treatment

INTRODUCTION

Parenting stress is often heightened in mothers receiving treatment for substance use. Experiences of trauma are commonly seen in this population, which may give rise to Posttraumatic Stress Disorder (PTSD) symptoms, including intrusion, avoidance, negative cognition and mood, and affective arousal. While past research has demonstrated a significant relation between PTSD symptoms and parenting stress, no studies have examined the relative contributions of these symptoms to parenting stress in mothers engaged in substance use treatment.

METHODS

Seventy-four mothers attending outpatient substance use treatment who were parenting children aged 0-3 years completed measures of parenting stress, PTSD, substance use, and depression symptoms.

RESULTS

A canonical correlation analysis indicated two canonical variates accounting for significant variance between PTSD symptom clusters and parenting stress measures. The first canonical variate, primarily reflecting depressive and PTSD cognition and mood symptoms, was predominantly related to the parental distress aspect of parenting stress (40%). The second canonical variate, primarily reflecting intrusion and avoidance PTSD symptoms, was associated with increased parental perceptions of their child as difficult (10%).

CONCLUSION

Future research directions and clinical implications of these results are discussed for designing parenting interventions with mothers attending substance use treatment who present with PTSD symptoms.

Prosocial behaviour reduces unwanted intrusions of experimental traumatic memories

Following trauma exposure, people often experience involuntary intrusions of traumatic memories, i.e., flashbacks. How to reduce such unwanted intrusions attracts attention from basic and translational memory research, with a goal to safeguard mental well-being and promote resilience. Here, based on prosocial behaviour's well-documented psychological benefits, we hypothesized that post-trauma prosocial behaviour would causally reduce trauma-related symptoms, including involuntary intrusions. To test this novel hypothesis, we conducted two pre-registered lab studies (N = 180) using trauma films to induce lab-analogue trauma exposure. Following trauma exposure, participants were randomly assigned to prosocial or non-prosocial conditions. Specifically, in the prosocial condition, participants donated money to their preferred charities. In the non-prosocial conditions, participants completed either a neutral, number judgement task (Experiment 1) or a proself task (Experiment 2). Participants completed a 1-week intrusion diary and Impact of Event Scale-Revised (IES-R), to assess frequencies of traumatic intrusions and post-trauma stress disorder symptoms, respectively. Results showed that compared to non-prosocial behaviour, prosocial engagement (i.e. performing charitable donations) reduced involuntary traumatic intrusions in both lab settings and in their daily life as evidenced by 1-week intrusion diaries. While exploratory mediation analyses suggested that intrusion reduction was partly driven by enhanced positive affect afforded by prosocial behaviour, future studies are required to illuminate the underlying mechanisms. To the extent that post-trauma prosociality alleviated trauma-related symptoms, future research is warranted to investigate how various forms of prosocial behaviour in naturalistic setting could promote resilience following trauma exposure.

From Epidemic to Pandemic: Comparing Hospital Staff Emotional Experience Between MERS and COVID-19

Objective: Both Middle East Respiratory Syndrome (MERS) and Coronavirus Disease 2019 (COVID-19) have an emotional toll on healthcare workers (HCWs), but the difference of the impact between the two diseases remains unknown.Design: A cross sectional descriptive survey.Setting: A tertiary care hospital.Participants: 125 HCWs who worked during the 2014 MERS as well as the 2020 COVID-19 outbreaks in high-risk areas of the hospital including critical care, emergency room and COVID-19 clinics.Methods: The comprehensive survey comprised 5 sections and 68 questions and was administered to HCWs before availability of the COVID-19 vaccine. The survey evaluated hospital staff emotions, perceived stressors, external factors that reduced stress, personal coping strategies, and motivators for future outbreaks. The participants rated each question for MERS and COVID-19 simultaneously on a scale from 0-3. The responses were reported as mean and standard deviation, while Wilcoxon signed-rank test was used to calculate the difference in responses.Results: There were 102 (82%) participants who returned the questionnaire. The ritual of obsessive hand washing, emotional and physical fatigue, ongoing changes in infection control guidelines, fear of community transmission, and limitations on socialization and travel were the major stressors that were significantly worse during COVID-19 compared to MERS (P<0.05) and led to HCWs adoption of additional 'personal' coping strategies during COVID-19. There was no difference between COVID-19 and MERS, however, among preferences for 'external' factors made available to HCWs that could reduce stress or in their preferences for motivators to work in future outbreaks (P>.05).Conclusion: Both the MERS and COVID-19 outbreaks were emotionally draining for HCWs. However, COVID-19 was a relatively more stressful experience than MERS for HCWs and led to greater personal, behavioral, and protective adaptations by the hospital staff.

Cardiorespiratory fitness as protection against the development of memory intrusions: A prospective trauma analogue study

Intrusive and distressing memories are at the core of post-traumatic stress disorder (PTSD). Since cardiorespiratory fitness (CRF) has been linked with improved mental health, emotion regulation, and memory function, CRF may, by promoting these capabilities, protect against the development of intrusions after trauma. We investigated the CRF-intrusion relationship and its potential mediators in 115 healthy individuals, using a trauma film to induce intrusions. As potential mediators, we assessed indices of pre-trauma mental health such as heart rate variability, subjective and psychobiological peri-traumatic responses, and memory. Critically, results showed that higher CRF was related to fewer intrusions, but no mediators emerged for the CRF-intrusion relationship. These results indicate that individuals displaying higher CRF are less prone to develop traumatic memory intrusions. Future studies may want to investigate whether promoting fitness prior to possible trauma exposure can boost resilience against the development of debilitating re-experiencing symptoms of PTSD.

When Fear Shrinks the Brain: A Computational Model of the Effects of Posttraumatic Stress on Hippocampal Volume

Post-traumatic stress disorder (PTSD) is a psychiatric disorder often characterized by the unwanted re-experiencing of a traumatic event through nightmares, flashbacks, and/or intrusive memories. This paper presents a neurocomputational model using the ACT-R cognitive architecture that simulates intrusive memory retrieval following a potentially traumatic event (PTE) and predicts hippocampal volume changes observed in PTSD. Memory intrusions were captured in the ACT-R rational analysis framework by weighting the posterior probability of re-encoding traumatic events into memory with an emotional intensity term I to capture the degree to which an event was perceived as dangerous or traumatic. It is hypothesized that (1) increasing the intensity I of a PTE will increase the odds of memory intrusions, and (2) increased frequency of intrusions will result in a concurrent decrease in hippocampal size. A series of simulations were run and it was found that I had a significant effect on the probability of experiencing traumatic memory intrusions following a PTE. The model also found that I was a significant predictor of hippocampal volume reduction, where the mean and range of simulated volume loss match results of existing meta-analyses. The authors believe that this is the first model to both describe traumatic memory retrieval and provide a mechanistic account of changes in hippocampal volume, capturing one plausible link between PTSD and hippocampal volume.

The hollow: A theory on workplace bullying in nursing practice

BACKGROUND

Incivility and bullying within the profession of nursing remains a problem within the workplace. As a result, healthcare workplaces can become unhealthy and difficult for nurses to function within. Work productivity is impacted and patients' healthcare is placed at risk when nurses are emotionally and physically affected by workplace incivility and bullying. Clinical nurse leaders (CNLs) applying theoretical reasoning and nursing competencies' in addressing bullying and incivility within the workplace, can provide an organized and effective organizational approach to addressing bullying and incivility in work environments.

METHODS

Theoretical reasoning and nursing competencies in addressing bullying and incivility within the workplace, will be examined as a means to identify nurses exhibiting signs and symptoms of bullying and incivility in work environments. The theory of The Hollow will identify the origins of affected nurses' behaviors and the physiological and psychological impact of bullying and incivility. The CNL role will be used as a facilitator of change at the microsystem level. And competencies for addressing behaviors associated with bullying and incivility will be addressed.

APPROACH

Innovation adapted from prior research and literature developed by the author, extrapolated from the literature on workplace bullying and incivility in nursing practice.

OUTCOMES

Bullying and incivility can be resolved in the workplace when competencies are set forth by nursing leaders to educate and empower nursing staff on expectations of healthy work environments.

CONCLUSION

Healthy workplaces are achievable when nurse leaders, such as CNLs, educate and empower nurses to have the expectation of healthy work environments not only for themselves, but for all nurses.

Retrieval effort or intention: Which is more important for participants' classification of involuntary and voluntary memories?

Theories of autobiographical memory distinguish between involuntary and voluntary memories. While involuntary memories are retrieved with no conscious intention and are therefore unexpected, voluntary memories are both intended and expected. Recent research has shown that participants sometimes classify their memories as either involuntary or voluntary based on retrieval effort instead of intention. These findings question whether intention really is the defining difference between these two types of retrieval or whether retrieval effort is also an important determinant. In two experimental studies, we investigated the extent to which participants rely on retrieval effort while classifying their memories as involuntary or voluntary. We created experimental conditions that maximize the probability of one type of retrieval while minimizing the probability of another type. Participants reported autobiographical memories in each condition while the programme registered their retrieval time. They then classified their memories as either voluntary or involuntary and rated all memories on perceived retrieval effort. This gave us four categories of memories: experimentally defined voluntary and involuntary memories with an objective measure of effort (retrieval time) and subjectively classified involuntary and voluntary memories with a subjective measure of effort. This allowed us to investigate the relative contribution of intention and effort to involuntary and voluntary memories. We replicated and extended previous findings by showing that the majority of memories were classified as involuntary independently of whether they were retrieved in the experimentally defined voluntary or involuntary condition. This could indicate that subjective effort is more important than intention for the involuntary-voluntary distinction in contrast with existing theories. We discuss theoretical and methodological implications of this finding.

Prospective associations between intelligence, working memory capacity, and intrusive memories of a traumatic film: Potential mediating effects of rumination and memory disorganization

BACKGROUND AND OBJECTIVES

Field research indicates that lower intelligence may predispose trauma-exposed individuals towards the development of re-experiencing symptoms. However, this assumption requires further testing in controlled prospective studies. In the current analog study, we tested whether lower fluid intelligence and lower working memory capacity (WMC) independently contribute to intrusion development. Moreover, we investigated potential mediating effects of trauma memory characteristics and trait rumination.

METHODS

118 healthy participants completed tests measuring fluid intelligence and WMC. Two days later, they were exposed to a film clip depicting traumatic events (i.e., so-called trauma film). After exposure to the film, intrusions were assessed using a diary and an intrusion triggering task.

RESULTS

Our analyses revealed a negative correlation between fluid intelligence and intrusions during the intrusion triggering task. WMC did not correlate with any intrusion measure. Moreover, planned analyses did not yield any mediation effects.

LIMITATIONS

We used the trauma film paradigm to examine analog posttraumatic stress symptoms. This approach limits the generalizability of our findings with regard to symptom development following real-life traumatic events.

CONCLUSIONS

Our results show for the first time that higher fluid intelligence is associated with fewer intrusions of a trauma film. This association was evident for laboratory but not for ambulatory intrusions. By demonstrating this association using a prospective experimental design, our study importantly corroborates previous field research.

Is romantic partner betrayal a form of traumatic experience? A qualitative study

According to a growing body of research, betrayal by a romantic partner is increasingly considered as a form of interpersonal trauma. Between 30% and 60% of betrayed individuals experience symptoms of post-traumatic stress disorder (PTSD), depression and anxiety to clinically meaningful levels. From a clinical perspective, this constellation of symptoms can be conceptualized as a stressor-related adjustment disorder. Yet, no qualitative research has examined the association between romantic betrayal and traumatic stress from the perspective of betrayed individuals. Face-to-face semi-structured interviews were conducted with 13 participants who had completed a clinical trial for a new treatment for adjustment disorder stemming from betrayal. Data were analysed using thematic content analysis. Although betrayal was experienced as a shocking and destabilizing event, and participants used trauma or 'feeling traumatized' as a metaphor to describe their experience, few had constructed their reaction as traumatic stress. In fact, participants reported experiencing difficulties understanding the intensity of their experience. However, when exposed to external sources (e.g., books and interviews by psychologists and researchers) that used a trauma and PTSD framework to explain the effects of betrayal, participants reported feeling clarity, validation and relief. Findings are discussed in the light of theoretical and clinical implications.

Feelings, Thoughts, and Behaviors During Disaster

Thoughts, feelings, and behaviors during traumatic events, that is, peritraumatic reactions, are key to post-trauma psychopathology development. Qualitative research is required to investigate whether existing quantitative methods capture the range and complexity of peritraumatic reactions as described by survivors. Semi-structured interviews were conducted with 104 earthquake survivors. Participants reported experiencing various peritraumatic reactions (M = 21, range = 6-43). The survivors' accounts confirmed presence and overall phenomenological characteristics of commonly studied peritraumatic reactions such as dissociation, distress, mental defeat, and immobility. In addition, novel and understudied reactions were identified: cognitive overload, hyperfocus, and emotion regulation, as well as positive affect. Finally, a number of cross-cutting phenomena were identified such as the social nature of many reactions and survivors evaluating their reactions as difficult to put into words. These findings have implications for the conceptualization of peritraumatic reactions, for trauma-focused psychotherapeutic interventions, and for the wellbeing of disaster survivors.

Cortical midline structures associated with rumination in women with PTSD

Elevated rumination, characterized by repetitive, negative self-focused cognition, is common in posttraumatic stress disorder (PTSD) and has been shown to predict the onset and maintenance of the disorder. Neuroimaging research has implicated cortical midline brain structures, including the rostral anterior cingulate cortex (rACC), posterior cingulate cortex (PCC), and isthmus cingulate (IsthCing), in rumination in healthy and depressed populations. While past research has revealed dysfunction in cortical midline regions in PTSD, no studies have yet investigated the structural and functional neural mechanisms underlying rumination in women with PTSD. In the current study, we used structural MRI and resting-state fMRI to examine relationships between rumination and brain volume, as well as resting-state functional connectivity (rsFC) of cortical midline structures in women with PTSD due to interpersonal trauma (N = 71). We performed multiple linear regression analyses to relate brain volume in rACC, PCC, and IsthCing regions to self-reported rumination, after controlling for age and total intracranial volume. We also conducted standard seed-based voxelwise rsFC analyses for significant regions identified in the structural analysis. We found a significant relationship between greater rumination and volume in the left IsthCing (p = .025). Results from the rsFC analyses revealed a significant relationship between greater rumination and diminished rsFC between the left IsthCing and left precuneus (p_FWE < .05). These findings provide novel support for alterations in the neural substrates of ruminative thought in women with PTSD. More broadly, we discuss clinical implications for targeted interventions to reduce rumination through psychotherapy or non-invasive brain stimulation.