Intrusive Traumatic Reexperiencing: Pathognomonic of the Psychological Response to Traumatic Stress

Post-earthquake dizziness and its psychiatric comorbidities among adolescents following the 2023 Kahramanmaraş earthquakes in Turkey

OBJECTIVE

Natural disasters, such as earthquakes, have detrimental effects on mental health. The occurrence of dizziness following earthquakes, termed post-earthquake dizziness syndrome (PEDS), has been noted in the epicenter and surrounding areas. The current study aimed to explore the prevalence of PEDS and its association with psychiatric disorders among adolescents.

METHODS

The sample consisted of 100 adolescents, aged 10-17 years, who had no history of vertigo or dizziness and were treated at a child and adolescent psychiatry outpatient clinic.

RESULTS

In the aftermath of the earthquake, 68.0% of the adolescents reported experiencing PEDS. A higher prevalence of PEDS was found among female adolescents compared to males. The most frequently reported symptom of PEDS was a sensation of ground shaking, typically experienced indoors within a week following the earthquake. Unpaired t-test analysis revealed that adolescents with PEDS had significantly higher scores on scales measuring panic disorder, generalized anxiety disorder, and post-traumatic stress disorder compared to those without PEDS.

CONCLUSIONS

In summary, the findings highlight the potential association between PEDS and psychiatric disorders in adolescents. However, the underlying mechanisms remain elusive, necessitating further research to elucidate the connections between PEDS and psychiatric conditions for more effective treatment strategies.

Functional correlates of a novel 8-factor model of PTSD in U.S. military veterans: Results from the National Health and Resilience in Veterans Study

Emerging evidence indicates that more nuanced models of posttraumatic stress disorder (PTSD) may better capture the condition's symptom structure. Recent theoretical and empirical work suggest that an 8-factor model of PTSD with separate internally- (e.g. flashbacks) and externally- (e.g. trauma-cue related physiological reactivity) generated intrusive symptom clusters may advance understanding of PTSD and its treatment and course. However, the model's functional and clinical significance still requires evaluation. To this end, we analyzed data from the National Health and Resilience in Veterans Study, a nationally representative sample of 3847 trauma-exposed U.S. military veterans. Multivariable regressions were performed to assess the relationship between the 8 PTSD symptom clusters, assessed using the PTSD Checklist for DSM-5, and clinical and functional measures. Results revealed that externally-generated intrusions were associated with higher odds of current depression and anxiety and worse mental, cognitive, and psychosocial functioning. Anhedonia (e.g., loss of interest in enjoyable activities) symptoms were associated with all the correlates tested, while negative affect (e.g., having strong negative feelings such as fear) symptoms were associated with all measures except depression. Avoidance symptoms were associated with lower odds of current anxiety while externalizing behavior symptoms were linked to higher odds of suicidal ideation. Anxious arousal symptoms were associated with lower odds of suicidal ideation but higher odds of PTSD-related impairment/distress, while dysphoric arousal symptoms were associated with higher odds of current depression, PTSD-related impairment/distress and worse mental and cognitive functioning. Results suggest that a more nuanced 8-factor model of PTSD symptoms may help inform understanding of the clinical and functional correlates of this multi-faceted disorder.

Evaluating a novel 8-factor dimensional model of PTSD in U.S. military veterans: Results from the National Health and Resilience in Veterans Study

BACKGROUND

Accumulating data suggest that the structure of posttraumatic stress disorder (PTSD) symptoms may be more nuanced than proposed by prevailing nosological models. Emerging theory further suggests that an 8-factor model with separate internally- (e.g., flashbacks) and externally- (e.g., trauma cue-related emotional reactivity) generated intrusive symptoms may best represent PTSD symptoms. To date, however, scarce research has evaluated the fit of this model and whether index traumas are differentially associated with it in populations at high risk for trauma exposure, such as military veterans.

METHODS

Data were analyzed from a nationally representative sample of 3847 trauma-exposed U.S. veterans who participated in the National Health and Resilience in Veterans Study. Confirmatory factor analyses were conducted to evaluate the fit of a novel 8-factor model of PTSD symptoms relative to 4-factor DSM-5 and empirically-supported 7-factor hybrid models.

RESULTS

The 8-factor model fit the data significantly better than the 7-factor hybrid and 4-factor DSM-5 models. Combat exposure and harming others were more strongly associated with internally-generated intrusions, while interpersonal violence and disaster/accident showed stronger significant associations with externally-generated intrusions.

LIMITATIONS

The 8-factor model requires validation in non-veteran and more diverse trauma-exposed populations, as well as with clinician-administered interviews.

CONCLUSIONS

Results of this study provide support for a novel 8-factor model of PTSD symptoms that is characterized by separate internally- and externally-generated intrusions. They also suggest that certain index traumas may lead to differential expression of these symptoms.

Intrusive Traumatic Re-Experiencing Domain: Functional Connectivity Feature Classification by the ENIGMA PTSD Consortium

Background

Intrusive traumatic re-experiencing domain (ITRED) was recently introduced as a novel perspective on posttraumatic psychopathology, proposing to focus research of posttraumatic stress disorder (PTSD) on the unique symptoms of intrusive and involuntary re-experiencing of the trauma, namely, intrusive memories, nightmares, and flashbacks. The aim of the present study was to explore ITRED from a neural network connectivity perspective.

Methods

Data were collected from 9 sites taking part in the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) PTSD Consortium (n= 584) and included itemized PTSD symptom scores and resting-state functional connectivity (rsFC) data. We assessed the utility of rsFC in classifying PTSD, ITRED-only (no PTSD diagnosis), and trauma-exposed (TE)-only (no PTSD or ITRED) groups using a machine learning approach, examining well-known networks implicated in PTSD. A random forest classification model was built on a training set using cross-validation, and the averaged cross-validation model performance for classification was evaluated using the area under the curve. The model was tested using a fully independent portion of the data (test dataset), and the test area under the curve was evaluated.

Results

rsFC signatures differentiated TE-only participants from PTSD and ITRED-only participants at about 60% accuracy. Conversely, rsFC signatures did not differentiate PTSD from ITRED-only individuals (45% accuracy). Common features differentiating TE-only participants from PTSD and ITRED-only participants mainly involved default mode network-related pathways. Some unique features, such as connectivity within the frontoparietal network, differentiated TE-only participants from one group (PTSD or ITRED-only) but to a lesser extent from the other group.

Conclusions

Neural network connectivity supports ITRED as a novel neurobiologically based approach to classifying posttrauma psychopathology.

Network analysis of posttraumatic stress disorder in a treatment-seeking sample of US firefighters and emergency medical technicians

BACKGROUND

First responders, including firefighters and emergency medical technicians (EMTs), are under extreme stress from repeated exposure to potentially traumatic events. To optimize treatment for this population, it is critical to understand how the various posttraumatic stress disorder (PTSD) symptom factors are associated with one another so these relations may be targeted in treatment.

METHOD

Using a sample of treatment-seeking firefighters/EMTs (N = 342), we conducted a partial correlation network analysis of the eight-factor model. A Bayesian directed acyclic graph (DAG) was used to estimate causal associations between clusters.

RESULTS

Approximately 37 % of the sample screened positive for probable PTSD. Internal re-experiencing and external re-experiencing had the strongest edges. In the DAG, internal re-experiencing was the parent node and was potentially predictive of external re-experiencing, negative affect, dysphoric arousal, and avoidance.

LIMITATIONS

Data were drawn from a treatment-seeking sample that may not generalize to all firefighters/EMTs.

CONCLUSIONS

The current findings are consistent with prior research suggesting re-experiencing plays a critical role in developing and maintaining PTSD symptoms. Future research should investigate non-treatment-seeking first responders, as well as EMTs and firefighters as individual populations.

Not all traumas are created equal: Phenotypic heterogeneity of PTSD symptoms in relation to index traumas in U.S. military veterans

Posttraumatic stress disorder (PTSD) is prevalent in military veterans. Although exposure to trauma is subsumed under the diagnostic criteria for PTSD, there is great variability in index traumatic events, and the clinical presentation of PTSD may vary in individuals depending on the type of event experienced. We examined the relationship between different index traumas and PTSD symptoms in 3507 trauma-exposed U.S. military veterans who participated in the National Health and Resilience in Veterans Study. Results showed that interpersonal violence and combat/captivity was associated with greater overall severity of PTSD symptoms relative to illness/injury and disaster/accident. Interpersonal violence and combat/captivity were also associated with greater severity of intrusive, avoidance, negative affect, anhedonia, externalizing behaviors, and anxious and dysphoric arousal symptoms, relative to the other two categories. Implications of these findings for tailoring treatment approaches for PTSD in veterans are discussed.

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).

Clinical significance of novel 8-factor model of DSM-5 PTSD in national VA PTSD residential treatment data: Internally- v. externally-cued intrusions

BACKGROUND

Intrusion symptoms are a core defining feature of posttraumatic stress disorder (PTSD). It was recently proposed that intrusions may be comprised of two distinct underlying processes: internally-cued intrusions (e.g., trauma-related memories), and externally-cued intrusions (e.g., reactivity to trauma-related cues in one's environment). This is the first study to examine the functional correlates of these two intrusion clusters.

METHODS

Participants included 7460 veterans discharged from 40 Veterans Affairs PTSD residential programs across the United States in fiscal years 2018 through 2020. Latent network modeling and structural equation modeling were used to assess the fit of an 8-factor model of PTSD symptoms, which were assessed using the PTSD Checklist for DSM-5 (PCL-5) PTSD symptoms at admission, and its association with symptoms of depression and generalized anxiety, and emotional and physical functioning.

RESULTS

The 8-factor model, with separate intrusion factors, showed superior model fit to the DSM-5 4-factor, 5-factor dysphoric arousal, 6-factor anhedonia, and 7-factor hybrid models of PTSD. Internally-cued intrusions were uniquely associated with dysphoric arousal, decreased avoidance, and worse physical health functioning; whereas, externally-cued intrusions were uniquely associated with greater avoidance, anxious arousal, negative affect, increased generalized anxiety symptoms, and worse emotional functioning.

LIMITATIONS

Limitations include the cross-sectional design and use of self-report measures.

CONCLUSIONS

Findings provide initial support for the clinical utility of a novel 8-factor model of PCL-5 PTSD symptoms, which distinguishes internally- and externally-cued intrusions. These separate intrusion symptom clusters may offer greater specificity and utility in informing the prognosis of and tailored interventions for PTSD.

The Heterogeneity of Posttraumatic Stress Disorder in DSM-5

This diagnostic study reports patterns of DSM-5 posttraumatic stress disorder diagnostic presentations from multiple cohorts.

Disorders Specifically Associated With Stress in ICD-11

Background

After almost three decades of ICD-10 use for diagnostic purposes, the World Health Organization has conducted a systematic and elaborate evaluation to revise the classification of mental disorders in this system. This revision resulted in the 11th version (ICD-11), introduced in 2022. As one new feature, the ICD-11 forms a new grouping of mental disorders specifically associated with stress.

Method

The current review presents an overview of the diagnostic features and cultural specifications of disorders specifically associated with stress. This grouping includes posttraumatic stress disorder and complex posttraumatic stress disorder, prolonged grief disorder, adjustment disorder, as well as two diagnoses for children, reactive attachment disorder and disinhibited social engagement disorder.

Results

Overall, there is evidence for the improved clinical utility and applicability of these disorders. The disorders have been defined in a parsimonious way by few features, but they suffice for scientific purposes as well.

Conclusion

However, more research is needed to evaluate assessments for the diagnoses and diagnostic features in the ICD-11.

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.

Exploration of a Novel Model of Intrusive Symptoms in Posttraumatic Stress Disorder Among US Veterans

This cross-sectional study evaluates a posttraumatic stress disorder model that divides intrusions into internally and externally cued symptoms compared with existing models.

Remembering the earthquake: intrusive memories of disaster in a rural Italian community

BACKGROUND

Disasters can have long-lasting impacts on mental health. Intrusive memories have been found to be common and persistent in the aftermath of earthquakes.

OBJECTIVE

To explore, using diaries, intrusive memories' presence, content, characteristics, and relationship with probable post-traumatic stress disorder (PTSD) in a small rural community exposed to mass destruction and loss of life.

METHODS

Survivors of the 2016-2017 Central Italy earthquakes (N = 104) were first interviewed to investigate the presence of intrusive memories of the disaster. Those that reported intrusive memories were subsequently asked to complete a 7-day paper-and-pen diary tracking their spontaneous memories of the earthquake events.

RESULTS

Twenty months after the earthquakes, 49% (n = 51) of the sample reported having experienced intrusive memories post-earthquake and 38% (n = 39) reported at least one intrusive memory in their diaries. Memories were rated as being distressing, vivid, and experienced as a mixture of images and thoughts. The content of intrusive memories generally focused on sensations and experiences during the earthquake. Other common categories of content were the material environment and physical objects as well as human loss & death. Several memories had a social focus. A minority of memories contained more positive content as well as content from before and after the earthquake. Some participants (28%) experienced repeated intrusive memories of the same content. Memories of participants with and without probable PTSD did not significantly differ on characteristics or content.

CONCLUSIONS

Intrusive memories can be common, distressing, and persistent occurrences following disasters, even in survivors not suffering from probable PTSD.

HIGHLIGHTS

Intrusive memories were common, distressing, and vivid more than 1-year post-disaster.They captured peri-earthquake sensations, material destruction, death, and social interactions.No difference in content or characteristics was found between participants with and without probable PTSD.

A Crosswalk Study of DSM-IV and DSM-5 Criteria for PTSD from the DSM-5 Field Trials

Objective: Posttraumatic stress disorder (PTSD) is prevalent and sometimes severely disabling. Providing effective treatment for PTSD and addressing its social consequences require accurate diagnosis. PTSD criteria have changed in all editions of the American Diagnostic Criteria since introduction of the diagnosis in DSM-III in 1980. The DSM-5 Field Trials demonstrated very good inter-rater reliability for PTSD, but a crosswalk study comparing DSM-IV and DSM-5 criteria has potential to identify diagnostic differences generated by changed criteria. Methods: A DSM-IV to DSM-5 PTSD crosswalk study was conducted in real-world adult clinical treatment settings in two DSM-5 Field Trials sites, the Dallas (N = 93) and Houston (N = 48) Veterans Affairs medical centers. The crosswalk assessment was conducted by trained clinicians who interviewed the patients and rated both sets of criteria on a combined checklist. Results: PTSD prevalence differed insubstantially between criteria sets (42% vs. 45% and 55% vs. 52% in the Dallas and Houston sites, respectively), with moderate to excellent diagnostic agreement (reliability indicated, respectively, by κ = .53 and .93); however, substantial proportions of individuals diagnosed in one criteria set did not meet criteria in the other. Differences in cross-criteria diagnostic reliability were largely a function of differing definitions of criterion A trauma. Conclusions: Reliability across the two criteria sets was generally good to excellent, and diagnostic discrepancy predominantly reflected the elimination of criterion A2 in DSM-5 with a smaller contribution from changes to the avoidance and numbing criteria.

Evolution, Emotion, and Episodic Engagement

Although rodent research provides important insights into neural correlates of human psychology, new cortical areas, connections, and cognitive abilities emerged during primate evolution, including human evolution. Comparison of human brains with those of nonhuman primates reveals two aspects of human brain evolution particularly relevant to emotional disorders: expansion of homotypical association areas and expansion of the hippocampus. Two uniquely human cognitive capacities link these phylogenetic developments with emotion: a subjective sense of participating in and reexperiencing remembered events and a limitless capacity to imagine details of future events. These abilities provided evolving humans with selective advantages, but they also created proclivities for emotional problems. The first capacity evokes the "reliving" of past events in the "here-and-now," accompanied by emotional responses that occurred during memory encoding. It contributes to risk for stress-related syndromes, such as posttraumatic stress disorder. The second capacity, an ability to imagine future events without temporal limitations, facilitates flexible, goal-related behavior by drawing on and creating a uniquely rich array of mental representations. It promotes goal achievement and reduces errors, but the mental construction of future events also contributes to developmental aspects of anxiety and mood disorders. With maturation of homotypical association areas, the concrete concerns of childhood expand to encompass the abstract apprehensions of adolescence and adulthood. These cognitive capacities and their dysfunction are amenable to a research agenda that melds experimental therapeutic interventions, cognitive neuropsychology, and developmental psychology in both humans and nonhuman primates.

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.

Dissecting the heterogeneity of posttraumatic stress disorder: differences in polygenic risk, stress exposures, and course of PTSD subtypes

BACKGROUND

Definition of disorder subtypes may facilitate precision treatment for posttraumatic stress disorder (PTSD). We aimed to identify PTSD subtypes and evaluate their associations with genetic risk factors, types of stress exposures, comorbidity, and course of PTSD.

METHODS

Data came from a prospective study of three U.S. Army Brigade Combat Teams that deployed to Afghanistan in 2012. Soldiers with probable PTSD (PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition ≥31) at three months postdeployment comprised the sample (N = 423) for latent profile analysis using Gaussian mixture modeling and PTSD symptom ratings as indicators. PTSD profiles were compared on polygenic risk scores (derived from external genomewide association study summary statistics), experiences during deployment, comorbidity at three months postdeployment, and persistence of PTSD at nine months postdeployment.

RESULTS

Latent profile analysis revealed profiles characterized by prominent intrusions, avoidance, and hyperarousal (threat-reactivity profile; n = 129), anhedonia and negative affect (dysphoric profile; n = 195), and high levels of all PTSD symptoms (high-symptom profile; n = 99). The threat-reactivity profile had the most combat exposure and the least comorbidity. The dysphoric profile had the highest polygenic risk for major depression, and more personal life stress and co-occurring major depression than the threat-reactivity profile. The high-symptom profile had the highest rates of concurrent mental disorders and persistence of PTSD.

CONCLUSIONS

Genetic and trauma-related factors likely contribute to PTSD heterogeneity, which can be parsed into subtypes that differ in symptom expression, comorbidity, and course. Future studies should evaluate whether PTSD typology modifies treatment response and should clarify distinctions between the dysphoric profile and depressive disorders.