Unwanted memories of assault: what intrusion characteristics are associated with PTSD?

Research Review: Why do prospective and retrospective measures of maltreatment differ? A narrative review

BACKGROUND

Childhood maltreatment contributes to a large mental health burden worldwide. Different measures of childhood maltreatment are not equivalent and may capture meaningful differences. In particular, prospective and retrospective measures of maltreatment identify different groups of individuals and are differentially associated with psychopathology. However, the reasons behind these discrepancies have not yet been comprehensively mapped.

METHODS

In this review, we draw on multi-disciplinary research and present an integrated framework to explain maltreatment measurement disagreement.

RESULTS

We identified three interrelated domains. First, methodological issues related to measurement and data collection methods. Second, the role of memory in influencing retrospective reports of maltreatment. Finally, the motivations individuals may have to disclose, withhold, or fabricate information about maltreatment.

CONCLUSIONS

A greater understanding of maltreatment measurement disagreement may point to new ways to conceptualise and assess maltreatment. Furthermore, it may help uncover mechanisms underlying maltreatment-related psychopathology and targets for novel interventions.

Emphatic Memories and Their Meaning in Societal and Legal Contexts: A Narrative Review and Position Paper

BACKGROUND

Many past and ongoing conflicts in the world are associated with memories. The role of emphatic memories is however often neglected in conflict solving. Therefore, this narrative review gives a short introduction to the phenomenon of emphatic memories and implications for counteracting dysfunctional effects of emphatic memories.

SUMMARY

Memory has two connotations. One is remembering and knowing (I can remember when I got married) and on the other is reminding and emphasizing memories (I remind my partner of our wedding day). Memories are less a report on the past but result of current emotions and motives. Emphatic memories serve for self-portrayal and distinction from others, self-exculpation, accusation of others, justification of claims. They are regularly reproachful, have an aggressive character, and are distorted and pseudologic. This is also true on a societal level, as memories are used for defining social groups, and by this for political purposes, in order to juxtapose one group against the other. If memories are revoked, they are regularly accompanied with the very emotions, which were associated with the past event. Corresponding behavior is motivated. Many people suffer from memories and associated emotions and dysfunctional behavior, as is well described in the context of post-traumatic stress disorders. Also, social groups can as a whole suffer from negative emotions because of memories, which may go back up to thousand years. To ensure that memories do not adversely affect individuals and social groups, they should best be forgotten, or at least rescripted, in a way that they are disentangled from negative emotions and motives. An important psychological process in this regard is wisdom and forgiveness, which must not be confused with understanding, justification, tolerating, or reconciliation. Wisdom and forgiveness allow persons to close the books, act self-determined, find freedom from external events, and end suffering because of the past. It is a rational and emotional act.

KEY MESSAGES

Emphatic memories can cause that individuals and groups do not find peace and persistently provoke new conflicts. Internal and interactional peace can be found if memories are let alone and fade away. Forgiveness and wisdom describe avenues to let dysfunctional memories go.

Hot metacognition: poorer metacognitive efficiency following acute but not traumatic stress

Aberrations to metacognition-the ability to reflect on and evaluate self-performance-are a feature of poor mental health. Theoretical models of post-traumatic stress disorder propose that following severe stress or trauma, maladaptive metacognitive evaluations and appraisals of the event drive the development of symptoms. Empirical research is required in order to reveal whether disruptions to metacognition cause or contribute to symptom development in line with theoretical accounts, or are simply a consequence of ongoing psychopathology. In two experiments, using hierarchical Bayesian modelling of metacognition measured in a memory recognition task, we assessed whether distortions to metacognition occur at a state-level after an acute stress induction, and/or at a trait-level in a sample of individuals experiencing intrusive memories following traumatic stress. Results from experiment 1, an in-person laboratory-based experiment, demonstrated that heightened psychological responses to the stress induction were associated with poorer metacognitive efficiency, despite there being no overall change in metacognitive efficiency from pre- to post-stress (N = 27). Conversely, in experiment 2, an online experiment using the same metamemory task, we did not find evidence of metacognitive alterations in a transdiagnostic sample of patients with intrusive memory symptomatology following traumatic stress (N = 36, compared to 44 matched controls). Our results indicate a relationship between state-level psychological responses to stress and metacognitive alterations. The lack of evidence for pre- to post-stress differences in metamemory illustrates the importance for future studies to reveal the direction of this relationship, and consequently the duration of stress-associated metacognitive impairments and their impact on mental health.

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.

Decontextualized fear memories? Stronger conditioned fear responses during extinction learning and extinction recall in a safe context predict the development of long-term analog intrusions

BACKGROUND

Difficulties in the context-dependent modulation of conditioned fear are known for posttraumatic stress disorder and may explain the occurrence of intrusive memories in safe contexts. The current study therefore investigated if reduced context-dependent modulation of conditioned fear and its underlying neural circuitry constitute risk factors for the development of analog intrusions in response to an experimental trauma.

METHODS

Eighty-five healthy women participated in the trauma film paradigm to investigate the development of analog intrusions as well as explicit memory for an experimental trauma after one week and three months, respectively. Before, participants underwent a context-dependent fear conditioning paradigm during functional magnetic resonance imaging with fear acquisition in context A and extinction training in context B on a first day, as well as extinction recall in context B and fear renewal in a novel context C one day later. Skin conductance responses (SCRs) and blood oxygen level dependent responses were main outcome measures.

RESULTS

In addition to stronger fear acquisition in context A, stronger conditioned fear responses in the safe context B, as indicated by stronger conditioned SCRs or stronger activation of fear expressing regions during extinction learning and recall, predicted the development of long-term analog intrusions.

CONCLUSIONS

Stronger fear responses in safe and danger contexts were risk factors for the development of long-term analog intrusions and point to decontextualized fear memories and difficulties in the context-dependent modulation of conditioned fear. Altered fear conditioning processes and reduced storage of contextual information may cause the occurrence of fear independent of context.

Cognitive flexibility moderates the efficacy of a visuospatial intervention following exposure to analog trauma

BACKGROUND AND OBJECTIVES

Intrusive memories are the hallmark feature of Post-Traumatic-Stress-Disorder (PTSD). Recent studies show that a visuospatial intervention after viewing traumatic films reduces intrusive memories in healthy individuals. However, many individuals still exhibit high levels of symptoms following such an intervention, warranting continued investigation into specific characteristics moderating intervention effect. One such candidate is cognitive-flexibility, defined as the ability to update behavior according to contextual demands. The present study examined the interactive effect of cognitive-flexibility and a visuospatial intervention on intrusive memories, predicting that higher flexibility would be associated with stronger intervention effects.

METHODS

Sixty participants (Mage = 29.07, SD = 4.23) completed a performance-based paradigm evaluating cognitive-flexibility, watched traumatic films, and were allocated to either an intervention or a no-task control group. Intrusions were assessed by means of laboratory and ambulatory assessment, and the intrusion subscale of the Impact-of-Events-Scale-Revised (IES-R).

RESULTS

Participants in the intervention group experienced fewer laboratory intrusions than the control group. However, this effect was moderated by cognitive-flexibility: Whereas individuals with below-average cognitive-flexibility did not benefit from the intervention, it was significantly beneficial for individuals with average and above-average cognitive-flexibility. No group differences emerged in the number of ambulatory intrusions or IES-R scores. However, cognitive-flexibility was negatively correlated with IES-R scores across both groups.

LIMITATIONS

The analog design may limit the extent of generalization to real-world traumatic events.

CONCLUSIONS

These results point to a potentially beneficial effect of cognitive-flexibility on intrusion development, particularly in the context of visuospatial 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.

Changes in cognitive processes and coping strategies precede changes in symptoms during cognitive therapy for posttraumatic stress disorder

Theories of posttraumatic stress disorder (PTSD) highlight the role of cognitive and behavioral factors in its development, maintenance, and treatment. This study investigated the relationship between changes in factors specified in Ehlers and Clark's (2000) model of PTSD and PTSD symptom change in 217 patients with PTSD who were treated with cognitive therapy for PTSD (CT-PTSD) in routine clinical care. Bivariate latent change score models (LCSM) of session-by-session changes in self-report measures showed that changes in PTSD symptoms were preceded by changes in negative appraisals, flashback characteristics of unwanted memories, safety behaviours, and unhelpful responses to intrusions, but not vice versa. For changes in trauma memory disorganization and PTSD symptoms we found a bidirectional association. This study provides evidence that cognitive and behavioral processes proposed in theoretical models of PTSD play a key role in driving symptom improvement during CT-PTSD.

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

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

To sleep or not to sleep, that is the question: A systematic review and meta-analysis on the effect of post-trauma sleep on intrusive memories of analog trauma

Distressing intrusive memories of a traumatic event are one of the hallmark symptoms of posttraumatic stress disorder. Thus, it is crucial to identify early interventions that prevent the occurrence of intrusive memories. Both, sleep and sleep deprivation have been discussed as such interventions, yet previous studies yielded contradicting effects. Our systematic review aims at evaluating existing evidence by means of traditional and individual participant data (IPD) meta-analyses to overcome power issues of sleep research. Until May 16th, 2022, six databases were searched for experimental analog studies examining the effect of post-trauma sleep versus wakefulness on intrusive memories. Nine studies were included in our traditional meta-analysis (8 in the IPD meta-analysis). Our analysis provided evidence for a small effect favoring sleep over wakefulness, log-ROM = 0.25, p < .001, suggesting that sleep is associated with a lower number of intrusions but unrelated to the occurrence of any versus no intrusions. We found no evidence for an effect of sleep on intrusion distress. Heterogeneity was low and certainty of evidence for our primary analysis was moderate. Our findings suggest that post-trauma sleep has the potential to be protective by reducing intrusion frequency. More research is needed to determine the impact following real-world trauma and the potential clinical significance.

Tackling childbirth-related intrusive memories with a single-session behavioural intervention involving a visuospatial task: protocol for a single-blind, waitlist-controlled randomised trial

INTRODUCTION

Approximately 12.3% of mothers experience childbirth-related post-traumatic stress symptoms (CB-PTSS). However, evidence-based interventions to treat CB-PTSS are lacking. Intrusive memories (IM), a key CB-PTSS, are distressing and can trigger other PTSS by reliving the traumatic event. Emerging evidence shows that a behavioural intervention involving a visuospatial task (BI-VT) can reduce the number of IM and PTSS, supposedly by interfering with the reconsolidation of the trauma memory. This study aims to test the efficacy of a single-session BI-VT targeting IM to reduce the number of childbirth-related (CB-)IM and PTSS, in comparison to a waitlist control group (WCG).

METHODS AND ANALYSIS

In this multicentre, single-blind, randomised controlled trial being undertaken at one regional and one university hospital in Switzerland, 60 participants will be allocated to the Immediate Intervention Group (IIG), receiving the immediate intervention on day 15, and 60 participants to the WCG receiving the delayed intervention on day 30. All participants will report their CB-IM during the 2 weeks preimmediate and postimmediate intervention in diaries. The IIG will additionally report their CB-IM over weeks 5 and 6 postimmediate intervention. Self-report questionnaires will assess CB-PTSS at 2 weeks preimmediate and postimmediate intervention in both groups, and at 6 weeks postimmediate intervention in the IIG. A feedback questionnaire will evaluate the intervention acceptability. The primary outcome will be group differences in the number of CB-IM between the 2 weeks preimmediate and postimmediate intervention. Secondary outcomes will be CB-PTSS at 2 and 6 weeks postimmediate intervention, the number of CB-IM at weeks 5 and 6 postimmediate intervention, and intervention acceptability.

ETHICS AND DISSEMINATION

Ethical approval was granted by the Human Research Ethics Committee of the Canton of Vaud (study number 202200652). Participants will provide an informed consent before study participation. Results will be presented in peer-reviewed journals and at conferences.

TRIAL REGISTRATION NUMBER

NCT05381155.

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.

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

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

The effect of sleep on intrusive memories in daily life: a systematic review and meta-analysis of trauma film experiments

STUDY OBJECTIVES

To synthesize the literature on the effect of sleep versus wake on the frequency and distress of intrusive memories in everyday life after watching film clips with distressing content as a proxy for traumatic experiences.

METHODS

We conducted a systematic review by searching PubMed and PsychInfo. The last search was conducted on January 31, 2022. We included experimental studies comparing sleep and wake groups on intrusions using ecological diary methods, whereas studies lacking a wake control condition or relying solely on intrusion-triggering tasks or retrospective questionnaires were excluded. Meta-analyses were performed to evaluate the results. Risks of biases were assessed following the Cochrane guidelines.

RESULTS

Across 7 effect sizes from 6 independent studies, sleep (n = 192), as compared to wake (n = 175), significantly reduced the number of intrusive memories (Hedges' g = -0.26, p = .04, 95% CI [-0.50, -0.01]), but not the distress associated with them (Hedges' g = -0.14, p = .25, 95% CI [-0.38, 0.10]).

CONCLUSIONS

Although the results suggest that sleep reduces the number of intrusions, there is a strong need for high-powered pre-registered studies to confirm this effect. Risks of biases in the reviewed work concern the selection of the reported results, measurement of the outcome, and failure to adhere to the intervention. Limitations with the current meta-analysis include the small number of studies, which comprised only English-language articles, and the fact that it was not pre-registered.

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.

Sleep-Directed Hypnosis Improves Subjective Sleep Quality but not Extinction Memory After Exposure to Analog Trauma

Background

Evidence-based treatments of posttraumatic stress disorder (PTSD) aim to promote fear extinction learning. Post-learning sleep, particularly slow wave sleep (SWS), promotes memory consolidation and recall. Thus, boosting SWS might strengthen extinction recall. The current study investigated whether sleep-directed hypnosis designed to increase SWS and sleep quality improves extinction recall and reduces analog PTSD symptoms.

Method

In two subsamples (remote/laboratory), 211 healthy individuals underwent fear conditioning with a traumatic film clip. On the next evening, they underwent extinction training. Thereafter, the experimental group received sleep-directed hypnosis, whereas the control group listened to a control text. Extinction recall and generalization and film-related intrusions and rumination were assessed on the following morning.

Results

Subjective sleep quality declined following exposure to an aversive film. No group differences were found in SWS though exploratory analyses indicated less rapid eye movement sleep after hypnosis. After hypnosis, the experimental group reported improved sleep quality, whereas the control group showed a further deterioration. Hypnosis had no effects on extinction retention and generalization nor on analog intrusions and rumination.

Conclusion

The current results indicate that sleep-directed hypnosis may be beneficial for improving subjective sleep quality after trauma but not for enhancing extinction memory and reducing analog PTSD symptoms.

Using Buddhist Meditation-informed Hypnotic Techniques to Manage Rumination: Two Case Illustrations

Rumination is a clinical phenomenon that causes significant distress in clients who suffer from various psychological and physical disorders. It also has a deleterious impact on both therapeutic process and outcome. One approach that holds promise to manage rumination is mindfulness meditation in combination with clinical hypnosis. This article: (1) reviews the concept of and techniques to manage rumination in the Buddhist psychological framework, (2) introduces 2 simple mindfulness-based techniques to deal with rumination, i.e., mindful thought detachment and mindful dereflection, and (3) describes 2 case studies in which these strategies were applied successfully. Hypnosis-informed clinicians are encouraged to integrate these approaches in their practices.

Effective psychological therapy for PTSD changes the dynamics of specific large-scale brain networks

In posttraumatic stress disorder (PTSD), re-experiencing of the trauma is a hallmark symptom proposed to emerge from a de-contextualised trauma memory. Cognitive therapy for PTSD (CT-PTSD) addresses this de-contextualisation through different strategies. At the brain level, recent research suggests that the dynamics of specific large-scale brain networks play an essential role in both the healthy response to a threatening situation and the development of PTSD. However, very little is known about how these dynamics are altered in the disorder and rebalanced after treatment and successful recovery. Using a data-driven approach and fMRI, we detected recurring large-scale brain functional states with high temporal precision in a population of healthy trauma-exposed and PTSD participants before and after successful CT-PTSD. We estimated the total amount of time that each participant spent on each of the states while being exposed to trauma-related and neutral pictures. We found that PTSD participants spent less time on two default mode subnetworks involved in different forms of self-referential processing in contrast to PTSD participants after CT-PTSD (mtDMN+ and dmDMN+ ) and healthy trauma-exposed controls (only mtDMN+ ). Furthermore, re-experiencing severity was related to decreased time spent on the default mode subnetwork involved in contextualised retrieval of autobiographical memories, and increased time spent on the salience and visual networks. Overall, our results support the hypothesis that PTSD involves an imbalance in the dynamics of specific large-scale brain network states involved in self-referential processes and threat detection, and suggest that successful CT-PTSD might rebalance this dynamic aspect of brain function.

Mental health effects of the Gangwon wildfires

Background

The April 2019 wildfires in Gangwon Province, South Korea forced the evacuation of 1500 individuals and cost more than $100 million in damages, making it the worst wildfire disaster in Korean history. The purpose of this paper was to investigate the mental health effects on survivors following the wildfires.

Methods

Between April and May 2019, outreach psychological support services were delivered to people impacted by the wildfires. Post-disaster psychological responses using a checklist and the Clinical Global Impression Scale-Severity (CGI-S) were evaluated for 206 wildfires survivors. The CGI-S was administered consequently at 1, 3, and 6 months after baseline measurement.

Results

Among four response categories, somatic responses (76.2%) were most frequently observed among the wildfire survivors. Specifically, insomnia (59.2%), anxiety (50%), chest tightness (34%), grief (33%), flashbacks (33%), and depression (32.5%) were reported by over 30% of the participants. The mean CGI-S scores were significantly decreased at 1 month (mean score = 1.94; SE = 0.09) compared to baseline (mean score = 2.94; SE = 0.08) and remained at the decreased level until 6 months (mean score = 1.66; SE = 0.11). However, participants with flashbacks showed significantly higher CGI-S scores compared to those without flashback at 6 months.

Conclusions

Wildfire survivors have various post-disaster responses, especially somatic responses. While most participants’ mental health improved over time, a few of them may have experienced prolonged psychological distress after 6 months. Flashbacks were particularly associated with continuing distress. These results suggest that the characteristics of responses should be considered in early phase intervention and in follow-up plans for disaster survivors.

Association between spatial working memory and Re-experiencing symptoms in PTSD

BACKGROUND AND OBJECTIVES

Few studies have evaluated the link between working memory (WM) and post-traumatic stress disorder (PTSD). Further, it is unknown whether this relationship is accounted for by other relevant variables including negative affect, emotional dysregulation, or general non-WM-related cognitive control deficits, which are associated with PTSD. The purpose of this study was to determine the extent to which a computerized WM task could predict PTSD symptomology incrementally beyond the contribution of other relevant variables associated with PTSD.

METHODS

Thirty veterans were eligible to complete emotional symptom questionnaires, a heart-rate variability measure, and computerized tasks (i.e., emotional Stroop and automated complex span tasks). A three-stage hierarchical regression was conducted with the PCL-5 total score and symptom clusters (i.e., re-experiencing, avoidance, hyperarousal, and negative cognition/mood) as the dependent variable.

RESULTS

Results revealed that only the re-experiencing symptom cluster was significantly predicted by executive, verbal, and visuospatial WM tasks, which explained an additional 29.7% of the variance over and above other relevant variables. Most notably, the visuospatial task was the only WM task that significantly explained PCL-5 re-experiencing symptoms.

LIMITATIONS

This study was based on a small sample of veterans with PTSD and causality cannot be determined with this cross-sectional study.

CONCLUSIONS

Overall, the results suggest that deficits in visuospatial WM are significantly associated with PTSD re-experiencing symptoms after controlling for other relevant variables. Further research should evaluate whether an intervention to improve visuospatial WM capacity can be implemented to reduce re-experiencing symptoms.

Pattern differentiation and tuning shift in human sensory cortex underlie long-term threat memory

The amygdala-prefrontal-cortex circuit has long occupied the center of the threat system,¹ but new evidence has rapidly amassed to implicate threat processing outside this canonical circuit.^2-4 Through nonhuman research, the sensory cortex has emerged as a critical substrate for long-term threat memory,^5-9 underpinned by sensory cortical pattern separation/completion^10,11 and tuning shift.^12,13 In humans, research has begun to associate the human sensory cortex with long-term threat memory,^14,15 but the lack of mechanistic insights obscures a direct linkage. Toward that end, we assessed human olfactory threat conditioning and long-term (9 days) threat memory, combining affective appraisal, olfactory psychophysics, and functional magnetic resonance imaging (fMRI) over a linear odor-morphing continuum (five levels of binary mixtures of the conditioned stimuli/CS+ and CS- odors). Affective ratings and olfactory perceptual discrimination confirmed (explicit) affective and perceptual learning and memory via conditioning. fMRI representational similarity analysis (RSA) and voxel-based tuning analysis further revealed associative plasticity in the human olfactory (piriform) cortex, including immediate and lasting pattern differentiation between CS and neighboring non-CS and a late onset, lasting tuning shift toward the CS. The two plastic processes were especially salient and lasting in anxious individuals, among whom they were further correlated. These findings thus support an evolutionarily conserved sensory cortical system of long-term threat representation, which can underpin threat perception and memory. Importantly, hyperfunctioning of this sensory mnemonic system of threat in anxiety further implicates a hitherto underappreciated sensory mechanism of anxiety.

Acute stress reactivity and intrusive memory development: a randomized trial using an adjusted trauma film paradigm

Understanding the neurobiological and cognitive processes underlying the development of posttraumatic stress disorder (PTSD) and its specific symptoms may facilitate preventive intervention development. Severe traumatic stress and resulting biological stress system activations can alter contextual memory processes. This may provide a neurobiological explanation for the occurrence of intrusive memories following trauma. Investigating the associations between temporal aspects and individual variation in peri- and post-traumatic hypothalamic pituitary adrenal (HPA) axis and sympathetic nervous system (SNS) stress reactivity and memory processing may increase our understanding of intrusive symptom development. The experimental trauma film paradigm is commonly used for this purpose but lacks robust SNS and HPA axis activation. Here, we performed an RCT to investigate the effect of an adjusted trauma film paradigm containing an added brief psychosocial stressor on HPA and SNS stress reactivity throughout the experiment and intrusive memory frequency in the following week in healthy males (N = 63, mean age = 22.3). Secondary, we investigated effects on film-related declarative memory accuracy and intrusion-related characteristics, and associations between acute HPA and SNS stress reactivity, film-related memory, glucocorticoid receptor functioning and intrusion frequency and characteristics. Participants were randomized to the socially-evaluated cold pressor test (seCPT n = 29) or control condition (warm water n = 34) immediately prior to a trauma film. Linear Mixed Models revealed increased acute SNS and cortisol reactivity, lower recognition memory accuracy and more intrusions that were more vivid and distressing during the following week in the seCPT compared to control condition. Linear regression models revealed initial associations between cortisol and alpha amylase reactivity during the experimental assessment and subsequent intrusions, but these effects did not survive multiple comparison corrections. Thus, with this adjustment, we increased the translational value of the trauma film paradigm as it appears to elicit a stronger stress response that is likely more comparable to real-life trauma. The adapted paradigm may be useful to investigate individual variation in biological and cognitive processes underlying early post-trauma PTSD symptoms and could advance potential preventive interventions.

Reducing childbirth-related intrusive memories and PTSD symptoms via a single-session behavioural intervention including a visuospatial task: A proof-of-principle study

BACKGROUND

Intrusive memories (IMs) of traumatic events are a key symptom of posttraumatic stress disorder (PTSD), and contribute to its maintenance. This translational proof-of-principle study tested whether a single-session behavioural intervention reduced the number of childbirth-related IMs (CB-IMs) and childbirth-related PTSD (CB-PTSD) symptoms, in women traumatised by childbirth. The intervention was assumed to disrupt trauma memory reconsolidation.

METHODS

In this pre-post study, 18 participants, whose traumatic childbirth had occurred between seven months and 6.9 years before, received an intervention combining childbirth-related reminder cues (including the return to maternity unit) with a visuospatial task. They recorded their daily CB-IMs in the two weeks pre-intervention (diary 1), the two weeks post-intervention (diary 2; primary outcome), and in week 5 and 6 post-intervention (diary 3). CB-PTSD symptom severity was assessed five days pre-intervention and one month post-intervention.

RESULTS

Compared to diary 1, 15/18 participants had ≥ 50% fewer CB-IMs in diary 2. The median (IQR) reduction of the number of CB-IMs was 81.89% (39.58%) in diary 2, and persisted in diary 3 (n = 17). At one month post-intervention, CB-PTSD symptom severity was reduced by ≥ 50% in 10/18 participants. Of the 8 participants with a CB-PTSD diagnosis pre-intervention, none met diagnostic criteria post-intervention. The intervention was rated as highly acceptable.

LIMITATIONS

The design limits the causal interpretation of observed improvements.

CONCLUSION

This is the first time such a single-session behavioural intervention was tested for old and real-life single-event trauma. The promising results justify a randomized controlled trial, and may be a first step toward an innovative CB-PTSD treatment.

Intranasal oxytocin administration impacts the acquisition and consolidation of trauma-associated memories: a double-blind randomized placebo-controlled experimental study in healthy women

Intrusive memories are a hallmark symptom of post-traumatic stress disorder (PTSD) and oxytocin has been implicated in the formation of intrusive memories. This study investigates how oxytocin influences the acquisition and consolidation of trauma-associated memories and whether these effects are influenced by individual neurobiological and genetic differences. In this randomized, double-blind, placebo-controlled study, 220 healthy women received either a single dose of intranasal 24IU oxytocin or a placebo before exposure to a trauma film paradigm that solicits intrusive memories. We used a "general random forest" machine learning approach to examine whether differences in the noradrenergic and hypothalamic-pituitary-adrenal axis activity, polygenic risk for psychiatric disorders, and genetic polymorphism of the oxytocin receptor influence the effect of oxytocin on the acquisition and consolidation of intrusive memories. Oxytocin induced significantly more intrusive memories than placebo did (t(188.33) = 2.12, p = 0.035, Cohen's d = 0.30, 95% CI 0.16-0.44). As hypothesized, we found that the effect of oxytocin on intrusive memories was influenced by biological covariates, such as salivary cortisol, heart rate variability, and PTSD polygenic risk scores. The five factors that were most relevant to the oxytocin effect on intrusive memories were included in a Poisson regression, which showed that, besides oxytocin administration, higher polygenic loadings for PTSD and major depressive disorder were directly associated with a higher number of reported intrusions after exposure to the trauma film stressor. These results suggest that intranasal oxytocin amplifies the acquisition and consolidation of intrusive memories and that this effect is modulated by neurobiological and genetic factors. Trial registration: NCT03031405.

Psychometric Characteristics of the Oxford Grief Memory Characteristics Scale and Its Relationship With Symptoms of ICD-11 and DSM-5-TR Prolonged Grief Disorder

Difficulties with loss-related memories are hypothesised to be an important feature of severe and enduring grief reactions according to clinical and theoretical models. However, to date, there are no self-report instruments that capture the different aspects of memory relevant to grieving and adaptation after bereavement over time. The Oxford Grief-Memory characteristics scale (OG-M) was developed using interviews with bereaved individuals and was subject to exploratory and confirmatory factor analyses in a community sample (N = 676). Results indicated the scale was unidimensional and demonstrated excellent psychometric properties. The impact of memory characteristics on symptoms of Prolonged Grief Disorder (PGD) according to both ICD-11 and DSM-5-TR criteria were investigated using cross-lagged structural equation modelling in a three-wave longitudinal sample (N = 275) at baseline and 6 and 12 months later. Results indicated that loss-related memory characteristics predicted future symptoms of PGD after controlling for autoregressions, and concurrent associations between symptoms and memory characteristics. Cross-lagged associations between memory characteristics and symptoms were significant in the first 6 months of follow-up. After that, memory characteristics predicted future symptoms, but not the other way round. Theoretical and clinical utility of the scale and its features are discussed.

The Role of Implicit Memory in the Development and Recovery from Trauma-Related Disorders

Post-traumatic Stress Disorder is a chronic condition that occurs following a traumatic experience. Information processing models of PTSD focus on integrating situationally triggered sensory-emotional memories with consciously accessible autobiographical memories. Review of the nature of implicit memory supports the view that sensory-emotional memories are implicit in nature. Dissociation was also found to be associated with the development and severity of PTSD, as well as deficits in autobiographical memory. Moreover, disorganized attachment (DA) was associated with greater degrees of dissociation and PTSD, and like the defining neural activation in PTSD, was found to be associated with basal ganglia activity. In addition, subcortical neuroception of safety promotes a neurophysiological substrate supportive of social engagement and inhibition of fear-based responses. Furthermore, activation of representations of co-created imagined scenes of safety and secure attachment are associated with increases in this neurophysiological substrate. Repeated priming of secure attachment imagery was associated with modification of internal working models of DA along with reductions in dissociation and recovery from complex PTSD. In conclusion, it is posited that adequate recovery from extensive trauma experiences requires more than conscious elaboration of traumatic autobiographical memories and that the application of implicit nonconscious memory modification strategies will facilitate more optimal recovery.

Cannabis use and posttraumatic stress disorder: prospective evidence from a longitudinal study of veterans

BACKGROUND

Posttraumatic stress disorder (PTSD) is the most highly co-occurring psychiatric disorder among veterans with cannabis use disorder (CUD). Despite some evidence that cannabis use prospectively exacerbates the course of PTSD, which in turn increases the risk for CUD, the causal nature of the relationship between cannabis and psychiatric comorbidity is debated. The longitudinal relationship between PTSD diagnosis and traumatic intrusion symptoms with cannabis use and CUD was examined using cross-lagged panel model (CLPM) analysis.

METHODS

Prospective data from a longitudinal observational study of 361 veterans deployed post-9/11/2001 included PTSD and CUD diagnoses, cannabis use, and PTSD-related traumatic intrusion symptoms from the Inventory of Depression and Anxiety Symptoms.

RESULTS

A random intercept CLPM analysis that leveraged three waves (baseline, 6 months and 12 months) of cannabis use and PTSD-related intrusion symptoms to account for between-person differences found that baseline cannabis use was significantly positively associated with 6-month intrusion symptoms; the converse association was significant but reduced in magnitude (baseline use to 6-month intrusions: β = 0.46, 95% CI 0.155-0.765; baseline intrusions to 6-month use: β = 0.22, 95% CI -0.003 to 0.444). Results from the two-wave CLPM reveal a significant effect from baseline PTSD to 12-month CUD (β = 0.15, 95% CI 0.028-0.272) but not from baseline CUD to 12-month PTSD (β = 0.12, 95% CI -0.022 to 0.262).

CONCLUSIONS

Strong prospective associations capturing within-person changes suggest that cannabis use is linked with greater severity of trauma-related intrusion symptoms over time. A strong person-level directional association between PTSD and CUD was evident. Findings have significant clinical implications for the long-term effects of cannabis use among individuals with PTSD.

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.

Circadian influence on intrusive re-experiencing in trauma survivors' daily lives

BACKGROUND

The core clinical feature of posttraumatic stress disorder (PTSD) is recurrent re-experiencing in form of intrusive memories. While a great number of biological processes are regulated by sleep and internal biological clocks, the effect of 24-hour biological cycles, named circadian rhythm, has not been investigated in the context of intrusive memories.

OBJECTIVE

Here we examined effects of time of day on frequency and characteristics of intrusive re-experiencing.

METHODS

Fifty trauma survivors reported intrusive memories for 7 consecutive days using ecological momentary assessment in their daily life. We investigated (i) time-of-day dependent effects on frequency and distribution of intrusive re-experiencing in the overall sample as well as in PTSD versus non-PTSD and (ii) time-of-day dependent effects on the memory characteristics intrusiveness, vividness, nowness and fear.

RESULTS

Intrusive memories showed a curvilinear pattern that peaked at 2pm. Intrusive memories in the PTSD group showed a constant level of intrusive re-experiencing in the afternoon and evening, whereas a descending slope was present in the non-PTSD group. In PTSD, intrusive memories might thus be experienced in a more time-scattered fashion throughout the day, indicating chronodisruption. Intrusion characteristics did not follow this pattern.

CONCLUSION

Although preliminary and based on a small sample size, these findings contribute to a better understanding of the everyday occurrence and characteristics of intrusive memories, and point to the added value of examining time-dependent effects, which can directly inform prevention and intervention science.

Personal characteristics of World War Two survivor offspring related to the presence of indirect intrusions

Background: A substantial proportion of clinical World War Two survivor offspring reports intrusions about war events they did not experience themselves. Objective: To help identify factors that contribute to the development of such indirect intrusions (i.e. intrusions about non-self-experienced traumatic events), we examined the personal characteristics of survivor offspring that were related to the presence of indirect intrusions. To explore the specificity of these relationships, we compared characteristics related to the presence of indirect and direct intrusions (i.e. intrusions about self-experienced traumatic events). Methods: Participants (N = 98) were post-war offspring of World War Two survivors in treatment in one of two clinics specialized in mental health services for war victims. We assessed the presence of indirect and direct intrusions as well as the following personal characteristics: gender, education level, trait dissociation, affect intensity, attentional control, mental imagery, fantasy proneness, and current psychopathology. Results: Reports of indirect intrusions were more frequent in individuals high in fantasy proneness, trait dissociation, and current psychopathology. Reports of direct intrusions were more frequent in women, individuals scoring high on trait dissociation, affect intensity, and current psychopathology. Fantasy proneness was a unique correlate of indirect intrusions. Conclusions: These findings are consistent with the idea that intrusions are the result of (re)constructive processes affected by several factors including personal characteristics.

HIGHLIGHTS

Offspring of World War Two survivors often experience indirect intrusions.We examined personal characteristics related to indirect and direct intrusions.Fantasy proneness was the best predictor of indirect intrusions.Gender was the best predictor of direct intrusions.

COVID-19-related distress is associated with analogue PTSD symptoms after exposure to an analogue stressor

Background: The COVID-19 outbreak in early 2020 was associated with an immediate increase in mental health problems in a significant percentage of the general population. Therefore, it is crucial to investigate how the COVID-19 pandemic - as a psychosocial stressor - affected the aetiological processes of mental disorders. Previous research has shown that stress potentiates associative (fear) learning and analogue symptoms of posttraumatic stress disorder (PTSD) and that analogue PTSD symptoms can emerge in response to associative learning. Objective: We investigated whether distress in response to the COVID-19 outbreak support the development of intrusions and rumination after exposure to a non-COVID-19-related analogue trauma. Moreover, we examined if these effects are mediated by the strength of associative learning during analogue trauma. Method: 122 undergraduate university students participated in an online experiment between March and July 2020. They completed questionnaires measuring distress and rumination related to the COVID-19 outbreak. On a subsequent day, they went through an associative learning task, in which neutral stimuli were paired with the appearance of a highly aversive film clip. Subjective ratings were assessed as indicators of associative learning. On the next day, participants documented film-related intrusions and rumination. Results: COVID-19-related distress but not rumination was associated with post-film intrusion and rumination load. These effects were mediated by associative learning. Conclusions: The current findings are in line with the assumptions that stress enhanced both associative learning and PTSD symptoms. Specifically, they indicate that prolonged psychosocial stress - like during the COVID-19 outbreak - is linked to individual differences in memory processing of aversive events. Further confirmatory research is needed to replicate these results.

Taking a walk through time: aversive memory re-experiencing may be linked to spatio-temporal distance

BACKGROUND

Individuals with posttraumatic stress disorder (PTSD) often report intrusive memories that appear to lack the appropriate spatio-temporal context.

OBJECTIVE

We examined whether focusing on the spatio-temporal context of aversive autobiographical memories reduces negative emotions, appraisals, and re-experiencing symptoms.

METHODS

We recruited 109 healthy adults and had them rate emotionality, vividness, and re-experiencing of an aversive autobiographical memory. Furthermore, we assessed automatic associations of idiosyncratic memory triggers with the concepts 'past' vs. 'now', and self-reported sense of memory closure and distancing. To manipulate spatio-temporal memory (re-)organization, the experimental group (n = 53) performed a lifeline exercise in virtual reality (VR), where participants symbolically placed memory triggers along a path representing their own personal life story. The control group (n = 56) completed a non-personalized VR task.

RESULTS

We found a marked decrease in negative emotions, negative appraisals, and re-experiencing in the following week, but on average, the lifeline exercise was not superior to the control condition. However, those in the lifeline group with stronger trigger-past associations subsequently exhibited a more pronounced reduction in re-experiencing. Also, participants with a higher subjective sense of memory distancing reported less re-experiencing.

CONCLUSIONS

The findings lend tentative support for theoretical assumptions about PTSD, but the potential causal role of automatic associations with spatio-temporal information remains to be clarified.

Mental Imagery in Patients with Prolonged Grief Disorder: a Comparison with Matched Bereaved Healthy Controls

Mental imagery is a transdiagnostic feature that has been increasingly researched in mental disorders in the past years. This study is the first to investigate mental imagery in individuals suffering from Prolonged Grief Disorder (PGD), a new disorder which will be included into the new edition of the International Classification of Diseases and Related Health Problems (ICD-11).Our objective was to find out to what extent patients suffering from PGD differ from healthy, but equally bereaved, controls in terms of mental imagery, and how mental imagery is related to psychopathology. Patients with PGD and matched bereaved healthy controls (n = 54) completed a mental imagery questionnaire specifically designed for the study, and other established measures of psychopathology. Patients suffering from PGD reported mental images more frequently, had less control over them, and described negative images as more vivid than did healthy controls. Also, in reaction to mental images, patients less frequently experienced joy, but more often grief, anger and guilt. Besides these group differences, significant correlations between mental imagery other psychopathological measures could be found. Mental imagery is clearly related to PGD. The underlying mechanisms on whether it is a developing or maintaining factor need to be addressed in future studies. Future research should also investigate in what way mental imagery might be used in therapeutic approaches.

Post-Traumatic Stress Disorder Symptoms among Journalists Repeatedly Covering COVID-19 News

The coronavirus pandemic has resulted in many journalists repeatedly covering stories related to human suffering. This study investigates whether these journalists experienced higher rates of psychological distress, post-traumatic stress disorder (PTSD) and depressive symptoms than those who have been working during the pandemic yet covering stories other than COVID-19 and aims to identify what factors may protect journalists from developing trauma-related symptoms. We assessed journalists (n = 120) working during the COVID-19 pandemic using self-report measures. Journalists repeatedly covering COVID-19 stories had significantly higher psychological distress (η² = 0.04) and PTSD symptoms (η² = 0.08), but not depression, compared to journalists who did not report on COVID-19. Rumination and numbing in response to unwanted memories predicted PTSD symptoms (R² = 0.53) and may be risk factors for PTSD in this population. Unhelpful resilience appraisals distinguished journalists who reported on COVID-19 and who developed distressing re-experiencing symptoms from those who similarly reported on distressing material and who did not develop symptoms. Targeting resilience appraisals may be helpful in reducing re-experiencing symptoms after trauma exposure.

Neuromodulation of Visual Cortex Reduces the Intensity of Intrusive Memories

Aversive events can be reexperienced as involuntary and spontaneous mental images of the event. Given that the vividness of retrieved mental images is coupled with elevated visual activation, we tested whether neuromodulation of the visual cortex would reduce the frequency and negative emotional intensity of intrusive memories. Intrusive memories of a viewed trauma film and their accompanied emotional intensity were recorded throughout 5 days. Functional connectivity, measured with resting-state functional magnetic resonance imaging prior to film viewing, was used as predictive marker for intrusions-related negative emotional intensity. Results indicated that an interaction between the visual network and emotion processing areas predicted intrusions’ emotional intensity. To test the causal influence of early visual cortex activity on intrusions’ emotional intensity, participants’ memory of the film was reactivated by brief reminders 1 day following film viewing, followed by inhibitory 1 Hz repetitive transcranial magnetic stimulation (rTMS) over early visual cortex. Results showed that visual cortex inhibitory stimulation reduced the emotional intensity of later intrusions, while leaving intrusion frequency and explicit visual memory intact. Current findings suggest that early visual areas constitute a central node influencing the emotional intensity of intrusive memories for negative events. Potential neuroscience-driven intervention targets designed to downregulate the emotional intensity of intrusive memories are discussed.

Rumination Mediates the Relationship Between Negative Affect and Posttraumatic Stress Disorder Symptoms in Female Interpersonal Trauma Survivors

Prior research has identified both rumination and negative affect (NA) as dimensional constructs related to the development and maintenance of posttraumatic stress disorder (PTSD). While both dimensions demonstrate significant positive relationships with symptoms of PTSD, the relationship between the two within the context of the disorder has yet to be explored. Consistent with prior research in the social anxiety literature, the present study seeks to examine a model of mediation by which rumination accounts for the significant relationship between NA and PTSD symptoms. Participants included 65 female interpersonal trauma survivors diagnosed with PTSD using structured, clinician-administered interviews. Both NA and rumination were observed as significant predictors of PTSD symptoms, and the variables were significantly associated with each other. However, NA was no longer a significant predictor of PTSD symptoms when rumination was entered into the mediation model, suggesting full mediation of the relationship by rumination. Results from the current study suggest a complex relationship between NA and rumination in interpersonal trauma survivors with PTSD, such that a ruminative cognitive coping style may either mitigate or exacerbate PTSD symptoms in the presence of sustained negative emotion. The current findings provide support for a cognitive model of PTSD, within which PTSD symptoms are influenced via negative, ruminative cognitions. Primary implications of these results include (a) the consideration of assessment of rumination in interpersonal trauma survivors with PTSD in clinical settings; (b) the selection of treatment that may address a ruminative cognitive style in this population, given the mediation between subjective distress and PTSD symptoms by rumination; and (c) the necessity for the validation of this mediation model within other traumatized populations.

The Effects of Dissociation on Analogue Trauma Symptoms After Trauma Processing Among Women With Varying Histories of Lifespan Victimization

Research has identified two subtypes of posttraumatic stress disorder (PTSD); the traditional form that includes hyperarousal reactions, and the other involving ongoing dissociation. Dissociation has been reflected in the new diagnostic criteria for PTSD with the dissociative specification focused on the experience of high levels of depersonalization and/or derealization. PTSD that presents with ongoing dissociation appears to characterize complex cases of PTSD for individuals exposed to protracted trauma. Yet, our understanding of the role of dissociation in relation to PTSD symptoms is limited with inconsistent empirical findings. This study aims to elucidate the complex associations between trauma, dissociation, and trauma-relevant symptomatology. In total, 60 female interpersonal trauma survivors completed baseline measures of trauma and dissociation, and at least a week later, they completed self-report measures of state trauma intrusions, guilt, and anxiety before and after participating in a trauma recall task to examine dissociative tendencies on analogue trauma-related symptoms. After data collection, participants were categorized into two groups; individuals with multiple forms of lifetime interpersonal trauma versus individuals with trauma isolated to single-type trauma in childhood and/or adulthood. Results revealed trauma intrusions, guilt, and anxiety increased after trauma recall overall, though trauma groups differed in the manifestation of these outcomes. In addition, less depersonalization and greater derealization predicted increases in anxiety overall, though this only remained true for those exposed to multiple-type lifespan traumas. Results reveal dissociative tendencies may be most relevant in the processing of trauma-related material for those exposed to multiple types of trauma throughout the lifespan. Implications for treatment of trauma survivors with different clinical presentations are discussed.

Cross-Lagged Relationships Between Insomnia and Posttraumatic Stress Disorder in Treatment-Receiving Veterans

Insomnia is a risk factor for the development of posttraumatic stress disorder (PTSD) while it is also plausible that PTSD symptoms can maintain insomnia symptoms. The present study examined longitudinal bidirectional relationships between insomnia and PTSD symptoms in treatment-seeking veterans. Participants were 693 ex-serving members of the Australian Defence Force who participated in an accredited, hospital-based outpatient PTSD program. Participants completed self-reported assessments of PTSD and insomnia symptoms at four time points: intake, discharge, 3-month, and 9-months posttreatment follow-up. Cross-lagged pathway analyses indicated significant bi-directional pathways between insomnia symptoms and PTSD symptoms at most time points. A final cross-lagged model between insomnia symptoms and the PTSD symptom clusters indicated that the PTSD symptom paths on insomnia symptoms, between intake and discharge, were attributable to reexperiencing PTSD symptoms. In contrast, across posttreatment follow-up time points there were significant paths of insomnia symptoms on all PTSD symptom clusters except from insomnia at 3-months to avoidance symptom at 9-months. PTSD symptoms and insomnia symptoms have bidirectional associations over time that may lead to the mutual maintenance or exacerbation of each condition following PTSD treatment. Where residual insomnia symptoms are present post-treatment, a sleep-focussed intervention is indicated and a sequenced approach to treatment recommended.

Dysmorphic and illness anxiety-related unwanted intrusive thoughts in individuals with obsessive-compulsive disorder

BACKGROUND/OBJECTIVE

Unwanted intrusive thoughts (UITs) are considered normal variants of the obsessions found in obsessive-compulsive disorder (OCD). Similarly, intrusive and persistent preoccupations about appearance defects in body dysmorphic disorder (BDD) and images and thoughts about illness in illness anxiety disorder (IAD) are abnormal variants of the thoughts and concerns about appearance and health found in non-clinical individuals. This study examines whether patients with OCD have frequent and distressing UITs with contents related to BDD and IAD, in addition to OCD-related UITs.

METHOD

Thirty-nine participants with OCD (M_age  = 32.45, standard deviation [SD] = 11.57; 63% men) completed the Questionnaire of Unpleasant Intrusive Thoughts (QUIT), designed to assess obsessional, dysmorphic and illness anxiety UITs and their associated functional consequences (emotions, appraisals, and neutralizing or control strategies).

RESULTS

Up to 71% of the individuals with OCD experienced the three UIT modalities. As expected, OCD-related UITs were the most frequent, although were no differences among the three UIT contents in terms of the disturbance they caused. The OCD intrusions were the most interfering, egodystonic and dysfunctionally appraised, and they instigated more neutralizing behaviours. Nonetheless, all UITs instigate the need to do something to alleviate the discomfort caused by their intrusion and attempts to suppress them.

CONCLUSION

UITs with different contents not always related to typical obsessive themes are a common experience in patients with OCD. These UITs could have detrimental consequences for the course of the disorder itself, and they should be adequately addressed in both the assessment and treatment of these patients.

Intrusive memories as conditioned responses to trauma cues: An empirically supported concept?

Intrusions in posttraumatic stress disorder (PTSD) are clinically understood as conditioned responses (CRs) to trauma-cues; however, experimental evidence for this is limited. We subjected 84 healthy participants to a differential conditioned-intrusion paradigm, where neutral faces served as conditioned stimuli (CSs) and aversive film clips as unconditioned stimuli (USs). While one group only completed acquisition, another group additionally received extinction. Subsequently, participants provided detailed e-diary intrusion reports. Several key findings emerged: First, participants in both groups re-experienced not only USs but also CSs as content of their intrusions. Second, intrusions were elicited by cues resembling CSs, USs, and experimental context. Third, extinction reduced probability and severity of US intrusions, and accelerated their decay, and this was particularly the case in participants showing greater cognitive (US-expectancy) and physiological (SCR) differential responding to CS+ vs. CS- at end of acquisition (i.e., conditionability). Similarly, extinction reduced CS-intrusion probability and severity, but only in participants with greater cognitive conditionability. These results support conditioning's role in re-experiencing in two critical ways: (1) Conditioning during trauma provides cues that not only function as reminder cues, but also as content of intrusions; (2) After strong conditioning, weakening the original CS-US relationship via extinction reduces intrusion formation after analogue-trauma.

Prolonged grief and posttraumatic stress disorder following the loss of a significant other: An investigation of cognitive and behavioural differences

BACKGROUND

Cognitive behavioural correlates to bereavement-related mental health problems such a Prolonged Grief Disorder (PGD) and Posttraumatic Stress Disorder (PTSD) are of theoretical and clinical importance.

METHODS

Individuals bereaved at least six months (N = 647) completed measures of loss-related cognitions and behaviours (i.e., loss-related memory characteristics, negative appraisals, coping strategies, grief resilience, and perceived social disconnection) and measures of PGD and PTSD symptoms. Individuals were assigned to one of four groups depending on probable clinical diagnoses (No-PGD/PTSD, PTSD, PGD, PGD+PTSD).

RESULTS

Results indicated that higher loss-related memory characteristics and lower grief resilience increased the likelihood of a clinical problem. The PGD and PGD+PTSD groups reported significantly higher loss-related memory characteristics and appraisals compared to the PTSD group. Social disconnection increased the likelihood of comorbid PGD+PTSD in comparison to any other group.

CONCLUSIONS

Results indicate cognitive differences between loss-related cognitions, memory characteristics and coping strategies between PGD and PTSD, and points to distinct cognitive correlates to psychopathology following loss.

Attentional processes and contamination-related intrusion distress

Whilst people with high contamination fear may not experience a greater number of contamination-related intrusions than people with low contamination fear, they tend to experience heightened distress in response to such intrusions. The aim of the present study was to test the hypothesis that attentional bias to contamination-relevant information, and the variability of this attentional bias, moderates the degree to which high contamination fearful but not low contamination fearful individuals experience distress in response to contamination-related intrusions. Individuals with high (n = 31) or low (n = 44) contamination fear completed a lab-based session including questionnaires, a dot-probe measure of contamination-related attentional bias and attentional bias variability, and a contamination stressor video. Participants then completed a week-long contamination intrusions diary. There were significant differences in intrusion distress between those with low and high contamination fear in the anticipated direction, and attentional bias significantly moderated this relationship. Regardless of contamination fear level, greater attentional bias variability was associated with greater intrusion distress. These findings suggest that reducing attentional bias variability could potentially help to reduce distress elicited by contamination-related intrusions, while also highlighting the fact that attentional bias towards threat may protect against such distress in low contamination fearful individuals.

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.

Traumatic memories of childbirth relate to maternal postpartum posttraumatic stress disorder

The trauma memory is a crucial feature of PTSD etiology and maintenance. Nonetheless, the nature of memories associated with childbirth-related posttraumatic stress disorder (CB-PTSD) requires explication. The present study, as part of a larger project on psychological outcomes of childbirth, utilized a multi-method approach to characterize childbirth memories in relation to CB-PTSD symptoms. We here assessed 413 women who completed self-report measures pertaining to CB-PTSD, postpartum depression, and childbirth memories. Additionally, a subset of 209 women provided written childbirth narratives, analyzed using Linguistic Inquiry and Word Count software. Women endorsing CB-PTSD symptoms on the PTSD-Checklist (PCL)-5 reported more incoherent childbirth memories with more emotional and sensory details, and more frequent involuntary recall and reliving of the memory. They also indicated the childbirth experience was more central to their identity. Written narratives in those with probable CB-PTSD were characterized by less (positive) affective processes, and more cognitive processes. We infer that childbirth memories in women who endorse symptoms of CB-PTSD in the early postpartum period resemble those described in the general PTSD literature. This suggests that childbirth may be experienced as traumatic and evoke a traumatic memory, implicated in symptom endorsement. Opportunities for therapeutic interventions modifying traumatic memories of childbirth in women at risk for CB-PTSD need to be investigated. Future research examining characteristics of traumatic childbirth memories is needed to advance our understanding of this overlooked postpartum condition.

Peritraumatic dissociation revisited: associations with autonomic activation, facial movements, staring, and intrusion formation

BACKGROUND

Peritraumatic dissociation is purported to emerge together with attenuated autonomic arousal, immobility, and staring. However, empirical evidence is scarce and heterogeneous. Moreover, it is still a matter of debate whether these responses predict intrusion formation.

OBJECTIVE

The present trauma-analogue study examined associations between peritraumatic dissociation, autonomic activation, facial movements, staring, and intrusion formation.

METHOD

Seventy-one healthy women watched a highly aversive film, while autonomic activation (heart rate, respiratory sinus arrhythmia, skin conductance level), facial movements (temporal variations in corrugator electromyography), and staring (fixation duration, tracklength) were assessed. Afterwards, participants rated the intensity of dissociation during film viewing and reported intrusions and associated distress in a smartphone application for 24 hours.

RESULTS

Peritraumatic dissociation was linked to higher autonomic arousal (higher heart rate and, on a trend-level, lower respiratory sinus arrhythmia), increased facial movements, and staring (lower tracklength). Peritraumatic dissociation, higher autonomic arousal (higher heart rate and lower respiratory sinus arrhythmia), staring (higher fixation duration), and, on a trend-level, more facial movements were linked to higher intrusion load (number x distress of intrusions) and together explained 59% of variance. Skin conductance level was neither linked to peritraumatic dissociation nor intrusion load.

CONCLUSIONS

Our results suggest that, at low-dissociation-levels observed in trauma-analogue studies, peritraumatic dissociation may occur together with heightened autonomic arousal and facial movements, indexing increased negative affect. Staring might, irrespectively of dissociation-levels, serve as objective marker for dissociation. Together, peritraumatic dissociation and its psychophysiological correlates might set the stage for later intrusion formation.

A longitudinal investigation of the association between rumination, hostility, and PTSD symptoms among trauma-exposed individuals

BACKGROUND

Rumination, defined as perseverative thinking regarding the causes and consequences of psychological symptoms, is a risk and maintaining factor for PTSD. Existing work has largely focused on the extent to which rumination functions as a coping strategy used to avoid traumatic memories and associated emotions. However, rumination may also maintain negative thinking patterns, such as hostility, which has been positively associated with both rumination and PTSD symptoms. The current study therefore investigated the extent to which hostility was a significant mediator of the prospective association between rumination and PTSD symptoms.

METHODS

The sample consisted of 119 trauma-exposed individuals (48.7% female), who completed self-report questionnaires at three time points during a clinical trial.

RESULTS

When controlling for treatment condition and baseline depressive disorder diagnosis, hostility temporally mediated the effects of rumination on PTSD symptoms. Specificity analyses provided further support for the direction and specific variables examined in this model, such that rumination was positively and uniquely associated with later hostility.

LIMITATIONS

Our findings are limited by the use of a sample in which only 30% of participants met diagnostic criteria for a trauma-related disorder, as well as the administration of the rumination measure at only one time point.

CONCLUSIONS

Results suggest that rumination and hostility may be promising treatment and prevention targets for PTSD symptoms.

Wakefulness impairs selective consolidation of relevant trauma-associated memories resulting in more frequent intrusions

Recent studies show that sleep reduces intrusive memories after analog trauma. This effect is assumed to be caused by sleep's impact on memory consolidation. However, the underlying processes of this phenomenon have not been uncovered. Thus, the current study investigates the hypothesis that sleep reduces intrusive memories by supporting the selective consolidation of relevant memories. Seventy-five participants were exposed to traumatic picture stories before nocturnal sleep or wakefulness during daytime. Memory for relevant and irrelevant trauma-associated stimuli was assessed prior to and after the retention period. Consistent with the hypothesis, results demonstrate reduced memory loss for relevant as opposed to irrelevant trauma-associated stimuli after sleep but not after wakefulness. Moreover, an incremental retention benefit for relevant trauma-associated stimuli was negatively correlated with the number of intrusive trauma memories after wakefulness. These results suggest that lack of sleep impairs selective gating of relevant trauma-associated memories, thereby enhancing intrusion development after trauma.

Sleep Early After Trauma

Abstract. Posttraumatic stress disorder (PTSD) is characterized by intrusive re-experiencing of emotional memories of a traumatic event. Such memories are formed after exposure to trauma in the context of a cascading stress response including high levels of emotional arousal and stress hormone release. Sleep could be a key modulator of early memory formation and re-consolidation processes. Initial studies have investigated this association in this early time period, that is, hours and days after trauma exposure, and its role in modulating trauma memories and PTSD. The time is thus ripe to integrate findings from these studies. The current review consolidated evidence from five experimental and seven naturalistic studies on the association between trauma, sleep, and the development of intrusive emotional memories and PTSD, respectively. Together, the studies point to a potential protective role of sleep after trauma for the development of intrusive memories and PTSD. Findings regarding key sleep architecture features are more mixed and require additional investigation. The findings are important for prevention and intervention science.