Intrusive images in psychological disorders: characteristics, neural mechanisms, and treatment implications

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

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

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

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

A systematic review and meta-analysis of the traumatogenic phenotype hypothesis of psychosis

BACKGROUND

Developmental trauma increases psychosis risk and is associated with poor prognosis. It has been proposed that psychosis in survivors of developmental trauma gives rise to a distinct 'traumatogenic' phenotype.

AIMS

Given the implications for personalised treatment, we sought to explore the traumatogenic psychosis phenotype hypothesis in a systematic review and meta-analysis of studies comparing psychotic presentations between adults with and without developmental trauma histories.

METHOD

We registered the systematic review on PROSPERO (CRD42019131245) and systematically searched EMBASE, Medline and PsycINFO. The outcomes of interests were quantitative and qualitative comparisons in psychotic symptom expression (positive, negative, cognitive) and other domains of psychopathology, including affect regulation, sleep, depression and anxiety, between adults with and without experience of developmental trauma.

RESULTS

Of 34 studies included (N = 13 150), 11 were meta-analysed (n = 2842). A significant relationship was found between developmental trauma and increased symptom severity for positive (Hedge's g = 0.27; 95% CI 0.10-0.44; P = 0.002), but not negative symptoms (Hedge's g = 0.13; 95% CI -0.04 to 0.30; P = 0.14). Developmental trauma was associated with greater neurocognitive, specifically executive, deficits, as well as poorer affect, dissociation and social cognition. Furthermore, psychotic symptom content thematically related to traumatic memories in survivors of developmental trauma.

CONCLUSIONS

Our findings that developmental trauma is associated with more severe positive and affective symptoms, and qualitative differences in symptom expression, support the notion that there may be a traumatogenic psychosis phenotype. However, underdiagnosis of post-traumatic stress disorder may also explain some of these findings. More research is needed to explore this further.

Exploration of stress reactivity and fear conditioning on intrusive memory frequency in a conditioned-intrusion paradigm

BACKGROUND AND OBJECTIVES

The conditioned-intrusion paradigm was designed to provide insight into the relationship between fear conditioning and intrusive memory formation, which is relevant to understanding posttraumatic stress disorder symptoms and treatment. However, boundary conditions of this new paradigm have not been explored and it is currently not known whether findings from this work are valid in a clinical context.

METHODS

In the current study, we explored the relationship between stress reactivity to trauma film clips, usual exposure to violent media, renewal of fear conditioning using skin conductance as well as subjective ratings, and the effect of shock versus film clip during conditioning on the frequency of intrusive memories. An adapted fear conditioning paradigm using trauma clips as unconditional stimuli was used, and participants subsequently reported intrusive memories of the trauma clips.

RESULTS

Skin conductance responses to conditioned stimuli paired with shocks and film clips were significantly higher than conditioned stimuli paired with film clips alone. Subjective stress reactivity, previous exposure to violent media, and film valence rating were associated with the frequency of intrusive memories. No aspects of fear conditioning were associated with intrusive memories, and factor analysis suggested the fear conditioning and stress related to film clip viewing were mostly separate constructs. Similarly, content and triggers of intrusive memories were usually film-clip related rather than conditional stimulus related.

LIMITATIONS

We did not observe strong conditioning effects of the unconditional stimuli to conditional stimuli, which were shapes rather than high frequency stimuli such as faces.

CONCLUSIONS

These findings provide potential boundary conditions for this paradigm and suggest multiple ways in which the validity of the paradigm can be tested in the future.

Neural basis underlying the association between thought control ability and happiness: The moderating role of the amygdala

Thought control ability (TCA) plays an important role in individuals' health and happiness. Previous studies demonstrated that TCA was closely conceptually associated with happiness. However, empirical research supporting this relationship was limited. In addition, the neural basis underlying TCA and how this neural basis influences the relationship between TCA and happiness remain unexplored. In the present study, the voxel-based morphometry (VBM) method was adopted to investigate the neuroanatomical basis of TCA in 314 healthy subjects. The behavioral results revealed a significant positive association between TCA and happiness. On the neural level, there was a significant negative correlation between TCA and the gray matter density (GMD) of the bilateral amygdala. Split-half validation analysis revealed similar results, further confirming the stability of the VBM analysis findings. Furthermore, gray matter covariance network and graph theoretical analyses showed positive association between TCA and both the node degree and node strength of the amygdala. Moderation analysis revealed that the GMD of the amygdala moderated the relationship between TCA and happiness. Specifically, the positive association between TCA and self-perceived happiness was stronger in subjects with a lower GMD of the amygdala. The present study indicated the neural basis underlying the association between TCA and happiness and offered a method of improving individual well-being.

Can Listening to a Verbal Trauma Report Induce Intrusions? - Replication of a Randomized Trial

Recent evidence suggests that indirect verbal exposure to traumatic events can be sufficient to cause intrusions and other posttraumatic stress symptoms. In this study, we used a verbal trauma report to experimentally induce intrusions and a tactile task to manipulate the putative processes underlying intrusion development. Our findings indicate that the verbal report indeed induced intrusive recall. Moreover, the verbal report induced negative mood, state anxiety, and state dissociation, with mood and state dissociation predicting intrusion development. Additionally, the tactile task interfered with intrusion formation as indicated by the primary diary measure, but not the retrospective self-report. However, these results await further replication as this and previous trials suffered from limited statistical power. The findings support the reports by trauma therapists who experience secondary traumatization. They also challenge the assumption that all intrusions develop bottom-up from low-level sensory input via sensory representations. Future studies should explore differential processes for intrusion development based on their modality.

Severe Dissociative Experiences beyond Detachment in a Large Clinical Sample of Inpatients with Post-Traumatic Stress Disorder: Diagnostic and Treatment Implications

INTRODUCTION

The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) contains a dissociative subtype of post-traumatic stress disorder (PTSD) characterized by depersonalization and derealization. Yet, there is evidence that dissociative symptoms in PTSD go beyond this kind of detachment dissociation and that some patients present with additional compartmentalization dissociation in the form of auditory-verbal hallucination, amnesia, and identity alteration.

METHODS

Hence, in this study, we examined latent profiles of childhood trauma (Childhood Trauma Questionnaire), PTSD (Impact-of-Event Scale-Revised), and pathological dissociation (Dissociative Experiences Scale-Taxon; DES-T) in a large sample of severely traumatized inpatients with PTSD (N = 1,360).

RESULTS

Results support a three-class solution of the latent profile analysis with a PTSD class, a dissociative subtype class, and a third class characterized by more complex and more severe dissociative symptoms. Importantly, in our inpatient sample of patients with severe PTSD, the latter class was found to be the most prevalent. Both the exploratory character of our retrospective analysis of clinical routine data and the use of the DES-T limit the generalizability of our findings, which require methodologically more rigorous replication.

CONCLUSION

In severe PTSD, dissociative symptoms beyond detachment are highly prevalent. Diagnostic and treatment implications are discussed.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

Chronic activation of a negative engram induces behavioral and cellular abnormalities

Negative memories engage a brain and body-wide stress response in humans that can alter cognition and behavior. Prolonged stress responses induce maladaptive cellular, circuit, and systems-level changes that can lead to pathological brain states and corresponding disorders in which mood and memory are affected. However, it is unclear if repeated activation of cells processing negative memories induces similar phenotypes in mice. In this study, we used an activity-dependent tagging method to access neuronal ensembles and assess their molecular characteristics. Sequencing memory engrams in mice revealed that positive (male-to-female exposure) and negative (foot shock) cells upregulated genes linked to anti- and pro-inflammatory responses, respectively. To investigate the impact of persistent activation of negative engrams, we chemogenetically activated them in the ventral hippocampus over 3 months and conducted anxiety and memory-related tests. Negative engram activation increased anxiety behaviors in both 6- and 14-month-old mice, reduced spatial working memory in older mice, impaired fear extinction in younger mice, and heightened fear generalization in both age groups. Immunohistochemistry revealed changes in microglial and astrocytic structure and number in the hippocampus. In summary, repeated activation of negative memories induces lasting cellular and behavioral abnormalities in mice, offering insights into the negative effects of chronic negative thinking-like behaviors on human health.

Relationship between social cognition and emotional markers and acoustic-verbal hallucination in youth with post-traumatic stress disorder: Protocol for a prospective, 2-year, longitudinal case-control study

INTRODUCTION

Auditory-verbal hallucinatory experiences (AVH) have a 12% prevalence in the general pediatric population. Literature reports a higher risk of developing AVH in post-traumatic stress disorder (PTSD). The persistence of AVHs during adolescence represents a risk of evolution into psychotic disorders. Social cognition and emotional markers could be considered prodromes markers of this evolution. The objectives of this prospective observational study are to observe social cognition and emotional markers correlation with the presence and persistence of AVH over two years and with the evolution of PTSD and psychotic diagnosis.

METHODS AND ANALYSIS

This prospective case-control study, longitudinal over two years (with an interim reassessment at six months and one year), will include 40 participants aged 8 to 16 years old with a diagnosis of PTSD and without a diagnosis of psychosis according to the criteria of DSM-5 (K-SADS-PL). Subjects included are divided into two groups with AVH and without AVH matched by gender, age and diagnosis. The primary outcome measure will be the correlation between social cognition and emotional makers and the presence of AVH in the PTSD pediatric population without psychotic disorders. The social cognition marker is assessed with the NEPSY II test. The emotional marker is assessed with the Differential Emotion Scale IV and the Revised Beliefs About Voices Questionnaire. The secondary outcome measures are the correlation of these markers with the persistence of AVH and the evolution of the patient's initial diagnosis two years later.

DISCUSSION

The originality of our protocol is to explore the potential progression to psychosis from PTSD by cognitive biases. This study supports the hypothesis of connections between PTSD and AVH through sensory, emotional and cognitive biases. It proposes a continuum model from PTSD to psychotic disorder due to impaired perception like AVH.

TRIAL REGISTRATION

Clinical trial registration: ClinicalTrials.gov Identifier: NCT03356028.

Direct retrieval as a theory of involuntary autobiographical memories: evaluation and future directions

I evaluate the conception of direct retrieval as originally formulated in the Self-Memory System model (Conway & Pleydell-Pearce [2000]. The construction of autobiographical memories in the self-memory system. Psychological Review, 107(2), 261-288. https://doi.org/10.1037/0033-295X.107.2.261). In the hierarchical memory organisation proposed in the Self-Memory System model, direct retrieval is described as a bottom-up associative process. While its theoretical role within this model is clear, systematic empirical examination of direct retrieval, viewed as a natural and observable phenomenon, has been hampered by inconsistent operationalisations. Here, I suggest that direct retrieval should be treated as a theoretical concept, aiming at explaining the phenomenon of involuntary (spontaneously arising) autobiographical memories. I evaluate predictions derived from the concept of direct retrieval against findings on involuntary autobiographical memories obtained over the past 25 years. Most of these predictions are consistent with the evidence, notably, the enhanced episodic specificity and constructive nature of involuntary autobiographical memories. However, the theory also has critical limitations. It did not predict the frequent occurrence of involuntary recollections in daily life, exceeding the prevalence of voluntary memories. Additionally, it overlooked the early emergence of spontaneously arising event memories in ontogenesis and their presence in other species, such as great apes. Future advancements of the Self-Memory System model should integrate evolutionary perspectives to address these limitations.

Recurrent involuntary memories and mind wandering are related but distinct

Spontaneous thought is common in daily life, and includes recurrent involuntary autobiographical memories (IAMs; memories retrieved unintentionally and repetitively) and mind wandering (MW). Both recurrent IAMs and MW are often unintentional or unconstrained, and both predict symptoms of mental health disorders. However, not all MW is unintentional, and not all IAMs are unconstrained. To what extent do recurrent IAMs and MW converge versus diverge? Undergraduates (N = 2,701) completed self-report measures of recurrent IAMs, trait MW, and psychopathology (i.e., PTSD, depression, anxiety). Regressions indicated that recurrent IAMs were significantly associated with spontaneous MW, but not deliberate MW. Further, both spontaneous MW and recurrent IAMs had unique relationships with disorder symptoms. Results suggest that recurrent IAMs are related to MW to the extent that recurrent IAMs are spontaneous. Conversely, recurrent IAMs are distinct from MW to the extent that recurrent IAMs' associations with disorder symptoms could not be solely explained by trait MW (and vice versa). This work highlights related, but distinguishable, forms of spontaneous thought and their transdiagnostic links with psychopathology.

Intrusive thoughts and memories in adolescents with major depressive disorder or post-traumatic stress disorder

OBJECTIVES

Research in adults suggests that intrusive memories and intrusive thoughts (often referred to as intrusive cognitions) are common in members of the general population and are often seen in clinical disorders. However, little is known about the experience of intrusive cognitions in adolescents, particularly in adolescents with major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). The present study sought to gather fundamental data on these phenomena (i.e., frequency, characteristics and appraisals of intrusive cognitions) in adolescents with MDD and PTSD.

METHODS

Adolescents aged 11-18 with MDD (n = 11), PTSD (n = 13) and a non-clinical control group (n = 25) completed structured interviews concerning their intrusive memories and thoughts.

RESULTS

Intrusive thoughts were common in all three groups but were particularly frequently experienced in the MDD group. Intrusive memories were expectedly very common in the PTSD group but also experienced by over half of the adolescents with MDD. Both clinical groups reported more negative emotions in response to their intrusive thoughts or memories and appraised these cognitions more negatively than the non-clinical group.

CONCLUSION

Intrusive memories and thoughts are common experiences in adolescents with MDD and PTSD. Emotions and appraisals relating to these cognitions may be targets for psychological intervention in this age group. However, small sample sizes limit the conclusions that can be drawn. Replication is needed with larger numbers of clinical participants.

Emotional Changes during Imagery Rescripting of Aversive Social Memories in Social Anxiety Disorder: A Randomized Controlled Trial

INTRODUCTION

Imagery rescripting (ImRs) is a psychotherapeutic intervention targeting aversive memories. During the three-phase intervention, patients reexperience their aversive memory (phase 1), observe the scene from their adult perspective, and intervene to help their former selves (phase 2), and reexperience it again with the positive changes (phase 3). Previous studies have rarely investigated emotional and regulatory processes taking place during the intervention.

OBJECTIVE

This randomized controlled trial investigated self-reported affective and physiological responses during ImRs.

METHODS

Seventy-seven patients with social anxiety disorder (SAD) were randomly assigned to a single session of ImRs or a control intervention (recall and discussion of the memory) targeting an aversive social memory. Heart rate (HR) and heart rate variability (HRV) were assessed during and post hoc ratings of positive and negative feelings after baseline and the intervention phases.

RESULTS

Relative to the control intervention, ImRs resulted in an initial increase in negative feelings from baseline to phase 1 and a following larger (phase 1 to phase 2) and more stable (phase 2 to phase 3) decrease in negative feelings/increase in positive feelings. On the physiological level, during ImRs compared to the control intervention, mean HR was significantly higher during phase 1 and HRV during phase 3, each compared to baseline.

CONCLUSIONS

These results provide further information about the specific sequence of emotional responses on different response levels during ImRs, being consistent with known theories of emotional processing and supposed mechanisms of ImRs.

Two people making sense of a story: narrative exposure therapy as a trauma intervention in early intervention in psychosis

Background: Narrative exposure therapy (NET) is a recommended intervention for people with multiple trauma histories; however, research is lacking into its use with people experiencing psychosis, many of whom report multiple trauma histories.Objective: This study aimed to explore experiences of NET in early intervention in psychosis (EIP) services.Method: Eight clinicians and four experts with lived experience (experts by experience) of psychosis and multiple trauma were interviewed on a single occasion using two versions (clinician and expert by experience) of a semi-structured interview schedule. Data was analysed using thematic analysis.Results: Five overarching themes were generated, relating to fear and avoidance of memories, importance of trust, organizing memories and making new meaning, reconnecting with emotions, and considerations when delivering NET in EIP.Conclusions: Directly addressing the impact of multiple trauma in people experiencing first episode psychosis is frightening and emotive, but helps to address painful memories and organize them into a personal narrative. Increases in distress and anomalous experiences were carefully considered by clinicians, but typically outweighed by the benefits of NET. Challenges were comparable to those described in non-psychosis research. Implications for clinical practice and future research are outlined.

Basic processes and clinical applications of mental imagery in worry: A systematic review

BACKGROUND

In this systematic review, we aimed to synthesise existing research on the phenomenology of mental imagery among high worriers compared to healthy individuals, and to characterise the nature and effectiveness of existing imagery-related interventions in treatment of worry.

METHODS

PsycInfo, CENTRAL, EMBASE, Medline, Medline Epub, and PubMed were searched for studies examining the relationship between worry/GAD and mental imagery, or interventions using imagery in treatment of worry/GAD. We assessed study quality and used qualitative narrative synthesis to comprehensively map study results.

RESULTS

The search yielded 2589 abstracts that were assessed for eligibility independently by two authors. From this, 183 full texts were screened and 50 qualitatively synthesised. Twenty-seven reported an association between worry/GAD and an aspect of mental imagery. Here, overactive negative and worry imagery, and diminished positive future imagining, were associated with worry/GAD. Twenty-three studies reported an intervention. This literature suggested mixed findings regarding efficacy, including for imaginal exposure as an independent technique for GAD.

CONCLUSIONS

Findings support dysfunctional negative imagining and diminished positive prospective imagery in GAD. General imagining abilities remain intact, which is promising for efforts to utilise imagery in treatment. Further research is warranted to develop innovative clinical applications of imagery in treatment of GAD.

Self-guided imagery rescripting for worry images: A preliminary experimental investigation

BACKGROUND

Mental images of feared events are overactive and intrusive in generalized anxiety disorder (GAD). Imagery rescripting involves integration of positive or neutral imagery and corrective information into images to facilitate emotional processing, reduce imagery intrusions, and re-structure underlying schema. Yet only one known study has applied the technique to treatment of worry. The present study aimed first to examine the relationship between trait worry and properties of future-oriented worry images, and second to examine the efficacy of a self-guided imagery rescripting intervention in improving individuals' response to their worries.

METHODS

Participants recruited through Amazon Mechanical Turk (N = 365) identified their major worry and wrote the script of a worst-case scenario mental image. Participants were randomized to three conditions: re-writing the same worry image script (exposure), or writing scripts of either one or three positive alternative future-oriented images (rescripting conditions).

RESULTS

In preliminary analyses, trait worry negatively predicted participants' ratings of worry images, including valence and ability to cope, and positively predicted distress, anticipated cost, and belief in their negative meaning. In experimental analyses, linear mixed-effects models revealed anxious response and cognitive appraisal of the threat were significantly lower among participants allocated to rescripting relative to exposure. There was no effect of rescripting type.

CONCLUSIONS

This investigation demonstrated the impact of a future-oriented imagery rescripting task on anxiety and cognitive biases associated with real worries in an unselected sample. Results may contribute to the development of imagery rescripting interventions for GAD.

Trauma film viewing and intrusive memories: Relationship between salivary alpha amylase, endocannabinoids, and cortisol

The endogenous cannabinoid (ECB) system is a small molecule lipid signalling system that is involved in stress response activation and is associated with PTSD, but it is unclear whether salivary ECBs are part of the sympathetic nervous system response to stress. We conducted an adapted trauma film paradigm, where participants completed a cold pressor test (or control) while watching a 10-minute trauma film. We also collected saliva and hair samples and tested them for ECBs, cortisol, and salivary alpha amylase (sAA). As hypothesised, there were significant positive correlations between sAA activity and salivary ECB levels, particularly 2-arachidonoyl glycerol (2-AG), though ECBs were not correlated with sAA stress reactivity. Participants who had a significant cortisol response to the trauma film/stressor reported less intrusive memories, which were also less distressing and less vivid. This effect was moderated by arachidonoyl ethanolamide (AEA), where decreases in AEA post-stress were associated with more intrusive memories in cortisol non-responders only. This study provides new evidence for the role of ECBs in the sympathetic nervous system.

An examination of the potential core symptoms of posttraumatic stress disorder: What is integral after removing general psychopathology & distress?

Many confirmatory factor analyses (CFA) have examined the structure of posttraumatic stress disorder (PTSD) with some suggesting increased complexity (i.e., 6+ factors), while others suggesting a more refined structure (i.e., 2-factors). These competing PTSD structures may be due to conflation of non-trauma specific symptoms that have been added overtime. However, none of these studies examined if all symptoms being examined are specific to PTSD or potentially more related to general distress and psychopathology. The current study re-evaluated the structure of PTSD using bifactor exploratory factor analysis (EFA) to identify the construct's core symptoms. Data for EFA models were taken from a sample of Veterans (N = 694) attending outpatient therapy for PTSD and were cross-validated using CFA in a sample of 297 Veterans attending residential treatment. Clinician Administered PTSD Scale for DSM-5 (CAPS-5) at pre-treatment was used across sample. Factor analyses resulted in a 2-factor, bifactor model comprised of eight total items. Model fit was robust, RMSEA = 0 [0.000, 0.036]; robust CFI = 1; robust TLI = 1.017. The bifactor analytic approach captured what might be the core structure of PTSD, which were pathognomonic symptoms of PTSD (Factor one). A distinct second factor related to depression was also found. In identifying this structure, the model eliminates redundancies and lesser performing items and differentiates depressive reactions as potentially distinct and separate. Overall, these findings may assist in future research of PTSD by determining the unique elements of the construct within a veteran sample versus associated features, general psychological distress, and comorbid psychopathology.

Trauma Memory Characteristics and Neurocognitive Performance in Youth Exposed to Single-Event Trauma

Cognitive models of posttraumatic stress disorder (PTSD) highlight characteristics of trauma memories, such as disorganisation, as key mechanisms in the aetiology of the disorder. However, studies investigating trauma memory in youth have provided inconsistent findings. Research has highlighted that PTSD in youth may be accompanied by difficulties in neurocognitive functioning, potentially impacting ability to recall the trauma memory. The present study sought to investigate both trauma memory characteristics and neurocognitive functioning in youth aged 8-17 years. Youths exposed to single-event trauma, with (N = 29, Mage = 13.6, 21 female) and without (N = 40, Mage = 13.3, 21 female) a diagnosis of PTSD, completed self-report measures of trauma memory, a narrative memory task and a set of neurocognitive tests two to six months post-trauma. A group of non trauma-exposed youths (N = 36, Mage = 13.9, 27 female) were compared on narrative and neurocognitive tasks. Results indicated that trauma memories in youth with, versus without, PTSD were more sensory-laden, temporally disrupted, difficult to verbally access, and formed a more 'central' part of their identity. Greater differences were observed for self-reported memory characteristics compared to narrative characteristics. No between group differences in neurocognitive function were observed. Self-reported trauma memory characteristics highlight an important factor in the aetiology of PTSD. The observed lack of significant differences in neurocognitive ability potentially suggests that cognitive factors represent a more relevant treatment target than neurocognitive factors in single-event PTSD. Further research to understand the cognitive factors represented by self-reported trauma memory characteristics is recommended.

Threat Memory in the Sensory Cortex: Insights from Olfaction

The amygdala has long held the center seat in the neural basis of threat conditioning. However, a rapidly growing literature has elucidated extra-amygdala circuits in this process, highlighting the sensory cortex for its critical role in the mnemonic aspect of the process. While this literature is largely focused on the auditory system, substantial human and rodent findings on the olfactory system have emerged. The unique nature of the olfactory neuroanatomy and its intimate association with emotion compels a review of this recent literature to illuminate its special contribution to threat memory. Here, integrating recent evidence in humans and animal models, we posit that the olfactory (piriform) cortex is a primary and necessary component of the distributed threat memory network, supporting mnemonic ensemble coding of acquired threat. We further highlight the basic circuit architecture of the piriform cortex characterized by distributed, auto-associative connections, which is prime for highly efficient content-addressable memory computing to support threat memory. Given the primordial role of the piriform cortex in cortical evolution and its simple, well-defined circuits, we propose that olfaction can be a model system for understanding (transmodal) sensory cortical mechanisms underlying threat memory.

Parvalbumin interneuron activity in autism underlies susceptibility to PTSD-like memory formation

A rising concern in autism spectrum disorder (ASD) is the heightened sensitivity to trauma, the potential consequences of which have been overlooked, particularly upon the severity of the ASD traits. We first demonstrate a reciprocal relationship between ASD and post-traumatic stress disorder (PTSD) and reveal that exposure to a mildly stressful event induces PTSD-like memory in four mouse models of ASD. We also establish an unanticipated consequence of stress, as the formation of PTSD-like memory leads to the aggravation of core autistic traits. Such a susceptibility to developing PTSD-like memory in ASD stems from hyperactivation of the prefrontal cortex and altered fine-tuning of parvalbumin interneuron firing. Traumatic memory can be treated by recontextualization, reducing the deleterious effects on the core symptoms of ASD in the Cntnap2 KO mouse model. This study provides a neurobiological and psychological framework for future examination of the impact of PTSD-like memory in autism.

Ecological Momentary Assessments of Trauma-Related Intrusive Memories: Potential Clinical Utility

As the global prevalence of trauma rises, there is a growing need for accessible and scalable treatments for trauma-related disorders like posttraumatic stress disorder (PTSD). Trauma-related intrusive memories (TR-IMs) are a central PTSD symptom and a target of exposure-based therapies, gold-standard treatments that are effective but resource-intensive. This study examined whether a brief ecological momentary assessment (EMA) protocol assessing the phenomenology of TR-IMs could reduce intrusion symptoms in trauma-exposed adults. Participants (N=131) experiencing at least 2 TR-IMs per week related to a DSM-5 criterion A trauma completed a 2-week EMA protocol during which they reported on TR-IM properties three times per day, and on posttraumatic stress symptoms at the end of each day. Longitudinal symptom measurements were entered into linear mixed-effects models to test the effect of Time on TR-IMs. Over the 2-week EMA protocol, intrusion symptom severity (cluster B scores) significantly declined (t = -2.78, p = 0.006), while other symptom cluster scores did not significantly change. Follow-up analyses demonstrated that this effect was specific to TR-IMs (t = -4.02, p < 0.001), and was not moderated by survey completion rate, total PTSD symptom severity, or ongoing treatment. Our findings indicate that implementing an EMA protocol assessing intrusive memories could be an effective trauma intervention. Despite study limitations like its quasi-experimental design and absence of a control group, the specificity of findings to intrusive memories argues against a mere regression to the mean. Overall, an EMA approach could provide a cost-effective and scalable treatment option targeting intrusive memory symptoms.

Integrating and fragmenting memories under stress and alcohol

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

Do childhood experiences influence associations between posttraumatic stress disorder symptoms and positive autobiographical memories among military veteran students? An exploratory study

BACKGROUND

Evidence links posttraumatic stress disorder (PTSD) symptoms and features of positive autobiographical memories (accessibility, vividness, coherence, sharing, emotional intensity, distancing). There is a knowledge gap on how adverse childhood experiences (ACEs) and benevolent childhood experiences (BCEs) may influence these relationships.

OBJECTIVES

The current study explored whether the number ACEs or BCEs moderated associations between PTSD symptom severity and features of positive autobiographical memories.

DESIGN AND METHODS

The sample included 124 student military veterans who had experienced a trauma (Mage = 33.90; 77.4% male; 75.0% White).

RESULTS

Path analyses showed more PTSD symptom severity was significantly associated with less positive autobiographical memory vividness (β = -0.26, p = .019, R2 = 0.06). Further, the number of ACEs moderated the relationship between PTSD symptom severity and positive autobiographical memory accessibility (β = -0.25, p = .023, R2 = 0.10) and vividness (β = -0.20, p = .024, R2 = 0.10). Among individuals with more ACEs (1 SD above the mean) compared to those with fewer ACEs (1 SD below the mean), less accessibility and vividness of positive autobiographical memories was associated with greater PTSD symptom severity. The number of BCEs was not a significant moderator.

CONCLUSIONS

Positive memory-based interventions may be particularly useful to address PTSD symptoms among military veterans with a history of childhood adversity.

Understanding the structure of autobiographical memories: A study of trauma memories from the 1994 Rwandan genocide

How do we remember traumatic events, and are these memories different in individuals who experience post-traumatic stress? Some evidence suggests that traumatic events are mnemonically enhanced, or include more episodic detail, relative to other types of memories. Simultaneously, individuals with post-traumatic stress disorder (PTSD) have more non-episodic details in all of their memories, a pattern hypothesized to result from impairment in executive function. Here, we explore these questions in a unique population that experienced severely traumatic events more than 20 years ago - individuals who lived through the 1994 genocide in Rwanda. Participants recalled events from the genocide, negative events unrelated to the genocide, neutral events, and positive events. We used the Autobiographical Interview method to label memory details as episodic or non-episodic. We found that memories from the genocide showed robust mnemonic enhancement, with more episodic than non-episodic details, and contained more details overall than any other memory type. This pattern was not impacted by post-traumatic stress. Overall, this study provides evidence that traumatic events create vivid long-lasting episodic memories, in this case even more than 20 years later.

Deep Aphantasia: a visual brain with minimal influence from priors or inhibitory feedback?

The authors are both self-described congenital aphantasics, who feel they have never been able to have volitional imagined visual experiences during their waking lives. In addition, Loren has atypical experiences of a number of visual phenomena that involve an extrapolation or integration of visual information across space. In this perspective, we describe Loren's atypical experiences of a number of visual phenomena, and we suggest these ensue because her visual experiences are not strongly shaped by inhibitory feedback or by prior expectations. We describe Loren as having Deep Aphantasia, and Derek as shallow, as for both a paucity of feedback might prevent the generation of imagined visual experiences, but for Loren this additionally seems to disrupt activity at a sufficiently early locus to cause atypical experiences of actual visual inputs. Our purpose in describing these subjective experiences is to alert others to the possibility of there being sub-classes of congenital aphantasia, one of which-Deep Aphantasia, would be characterized by atypical experiences of actual visual inputs.

Spatiotemporal dynamics of hippocampal-cortical networks underlying the unique phenomenological properties of trauma-related intrusive memories

Trauma-related intrusive memories (TR-IMs) possess unique phenomenological properties that contribute to adverse post-traumatic outcomes, positioning them as critical intervention targets. However, transdiagnostic treatments for TR-IMs are scarce, as their underlying mechanisms have been investigated separate from their unique phenomenological properties. Extant models of more general episodic memory highlight dynamic hippocampal-cortical interactions that vary along the anterior-posterior axis of the hippocampus (HPC) to support different cognitive-affective and sensory-perceptual features of memory. Extending this work into the unique properties of TR-IMs, we conducted a study of eighty-four trauma-exposed adults who completed daily ecological momentary assessments of TR-IM properties followed by resting-state functional magnetic resonance imaging (rs-fMRI). Spatiotemporal dynamics of anterior and posterior hippocampal (a/pHPC)-cortical networks were assessed using co-activation pattern analysis to investigate their associations with different properties of TR-IMs. Emotional intensity of TR-IMs was inversely associated with the frequency and persistence of an aHPC-default mode network co-activation pattern. Conversely, sensory features of TR-IMs were associated with more frequent co-activation of the HPC with sensory cortices and the ventral attention network, and the reliving of TR-IMs in the "here-and-now" was associated with more persistent co-activation of the pHPC and the visual cortex. Notably, no associations were found between HPC-cortical network dynamics and conventional symptom measures, including TR-IM frequency or retrospective recall, underscoring the utility of ecological assessments of memory properties in identifying their neural substrates. These findings provide novel insights into the neural correlates of the unique features of TR-IMs that are critical for the development of individualized, transdiagnostic treatments for this pervasive, difficult-to-treat symptom.

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.

Acute Angiotensin II Receptor Blockade Facilitates Parahippocampal Processing During Memory Encoding in High-Trait-Anxious Individuals

Background

Angiotensin II receptor blockers (ARBs) have been associated with preventing posttraumatic stress disorder symptom development and improving memory. However, the underlying neural mechanisms are poorly understood. This study investigated ARB effects on memory encoding and hippocampal functioning that have previously been implicated in posttraumatic stress disorder development.

Methods

In a double-blind randomized design, 40 high-trait-anxious participants (33 women) received the ARB losartan (50 mg) or placebo. At drug peak level, participants encoded images of animals and landscapes before undergoing functional magnetic resonance imaging, where they viewed the encoded familiar images and unseen novel images to be memorized and classified as animals/landscapes. Memory recognition was assessed 1 hour after functional magnetic resonance imaging. To analyze neural effects, whole-brain analysis, hippocampus region-of-interest analysis, and exploratory multivariate pattern similarity analysis were employed.

Results

ARBs facilitated parahippocampal processing. In the whole-brain analysis, losartan enhanced brain activity for familiar images in the parahippocampal gyrus (PHC), anterior cingulate cortex, and caudate. For novel images, losartan enhanced brain activity in the PHC only. Pattern similarity analysis showed that losartan increased neural stability in the PHC when processing novel and familiar images. However, there were no drug effects on memory recognition or hippocampal activation.

Conclusions

Given that the hippocampus receives major input from the PHC, our findings suggest that ARBs may modulate higher-order visual processing through parahippocampal involvement, potentially preserving intact memory input. Future research needs to directly investigate whether this effect may underlie the preventive effects of ARBs in the development of posttraumatic stress disorder.

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.

When does imagery rescripting become a double-edged sword? - Investigating the risk of memory distortion through imagery rescripting in an online Trauma film study

Imagery Rescripting (ImRs) has proven effective in reducing involuntary emotional memories. However, it is unclear whether and when it may lead to reduced accuracy of voluntary memory. Although previous analogue studies suggest that ImRs does not pose a general risk regarding memory distortion, it can not be ruled out that ImRs could cause memory impairment under certain risk conditions. In our three-day online trauma film study we investigated in a healthy sample (N = 267) whether specific instructions during ImRs as typically provided in clinical practice (i.e., detailed imagery with a sensory focus) increase the risk of memory distortions. Additionally, we examined whether the completeness of the original memory moderates these instruction effects. Contrary to our expectations, a sensory focus during ImRs was associated with higher memory accuracy in a recognition task, independently of the quality of the original memory. These results extend previous findings by suggesting that ImRs does not even impair memory performance when the quality of the original memory is poor and when the production of sensory-rich images is specifically encouraged. Our results question current practices employed to assess witness statement credibility, which are partly based on concerns that trauma-focused interventions like ImRs undermine memory accuracy.

The effectiveness of two novel approaches to prevent intrusions: A pilot study comparing Tetris_dualtask and imagery rescripting to control

BACKGROUND AND OBJECTIVES

Post-traumatic stress disorder (PTSD) is a global health problem. Although effective treatments for it exist, early interventions that prevent PTSD from developing are lacking. The aim of this pilot analogue trauma study was to compare the effects of two potential early intervention strategies, namely Tetris_dualtask and imagery rescripting (IR) to a no-intervention control group on intrusion frequency and the vividness and emotionality of aversive film memory.

METHODS

Sixty healthy students were subjected to the trauma film paradigm and randomly allocated to either: Tetris_dualtask, IR or no-intervention. Main outcomes were the number of film-related intrusions at one week and vividness and emotionality ratings of the most aversive film memory. Secondary outcomes were PTSD-like symptoms, intrusion intensity, and explicit film memory.

RESULTS

The Tetris_dualtask group reported significant fewer intrusions compared to the no-intervention group; whereas the IR group did not. No effect was found on vividness and emotionality ratings, PTSD-like symptoms, intrusion intensity, and explicit memory.

LIMITATIONS

The sample size was small, and analogue trauma in healthy individuals was examined, thus generalizability may be limited. Also, to increase comparability between interventions, the duration of Tetris_dualtask and IR was standardized. As a result, the IR intervention was shorter compared to other studies, which might have decreased its efficacy.

CONCLUSIONS

The results of this pilot study suggest that playing Tetris during retrieval of traumatic images, might hold potential as an early intervention strategy to reduce intrusions in the early aftermath of trauma and adversity. However, future large-scale replication research is needed.

Mental threat rehearsal increases fear generalization

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

The Subjective Experience of Autobiographical Remembering: Conceptual and Methodological Advances and Challenges

The investigation of the phenomenology of autobiographical memories (i.e., how a memory is subjectively experienced and its meaning) has provided an important contribution to our understanding of autobiographical remembering. Over the last two decades, the study of phenomenology has received widespread scientific attention, and the field has undergone quite relevant conceptual and methodological changes. In the present work, we (1) review some basic and well-established research findings and methodological achievements; (2) discuss new theoretical and methodological challenges, with a special focus on the issue of the phenomenological experience of the retrieval process and its relationship with the phenomenology of the products of retrieval; and (3) propose an alternative way of conceptualizing and understanding it in the framework of experimental phenomenology.

Examining the association between posttraumatic stress disorder and disruptions in cortical networks identified using data-driven methods

Posttraumatic stress disorder (PTSD) is associated with lower cortical thickness (CT) in prefrontal, cingulate, and insular cortices in diverse trauma-affected samples. However, some studies have failed to detect differences between PTSD patients and healthy controls or reported that PTSD is associated with greater CT. Using data-driven dimensionality reduction, we sought to conduct a well-powered study to identify vulnerable networks without regard to neuroanatomic boundaries. Moreover, this approach enabled us to avoid the excessive burden of multiple comparison correction that plagues vertex-wise methods. We derived structural covariance networks (SCNs) by applying non-negative matrix factorization (NMF) to CT data from 961 PTSD patients and 1124 trauma-exposed controls without PTSD. We used regression analyses to investigate associations between CT within SCNs and PTSD diagnosis (with and without accounting for the potential confounding effect of trauma type) and symptom severity in the full sample. We performed additional regression analyses in subsets of the data to examine associations between SCNs and comorbid depression, childhood trauma severity, and alcohol abuse. NMF identified 20 unbiased SCNs, which aligned closely with functionally defined brain networks. PTSD diagnosis was most strongly associated with diminished CT in SCNs that encompassed the bilateral superior frontal cortex, motor cortex, insular cortex, orbitofrontal cortex, medial occipital cortex, anterior cingulate cortex, and posterior cingulate cortex. CT in these networks was significantly negatively correlated with PTSD symptom severity. Collectively, these findings suggest that PTSD diagnosis is associated with widespread reductions in CT, particularly within prefrontal regulatory regions and broader emotion and sensory processing cortical regions.

The effect of chronic academic stress on intentional forgetting

This study investigated whether chronic academic stress could affect the directed forgetting (DF) process. Both the stress group (undergoing preparation for a major academic examination) and the control group performed a DF task. A forgetting cue was presented after a to-be-forgotten (TBF) word, whereas no cue appeared after a to-be-remembered (TBR) item in the study phase. An old/new recognition test was used in the test phase. The results showed that (1) the stress group showed a higher level of self-reported stress, state anxiety, negative affect, and decreased cortisol awakening response (CAR) compared with the control group, suggesting a higher level of stress for the stress group. (2) Both groups showed superior recognition performance of TBR than TBF items, suggesting a DF effect. (3) The stress group showed inferior recognition performance of TBF items and an enhanced DF effect compared with the control group. These results demonstrated that the intentional memory control process might be enhanced under chronic academic stress.

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

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

Differential methylation of linoleic acid pathway genes is associated with PTSD symptoms - a longitudinal study with Burundian soldiers returning from a war zone

Soldiers may be exposed to traumatic stress during combat deployment and thus are at risk for developing posttraumatic stress disorder (PTSD). Genetic and epigenetic evidence suggests that PTSD is linked to forming stress-related memories. In the current study, we investigated post-deployment associations of PTSD symptoms with differential DNA methylation in a sample of Burundian soldiers returning from the African Union Mission in Somalia's war zone. We used a matched longitudinal study design to explore epigenetic changes associated with PTSD symptoms in N = 191 participants. PTSD symptoms and saliva samples were collected at 1-3 (t1) and 9-14 months (t2) after the return of the soldiers to their home base. Individuals with either worsening or improving PTSD symptoms were matched for age, stressful, traumatic and self-perpetrated events prior to the post-assessment, traumatic and violent experiences between the post- and the follow-up assessment, and violence experienced during childhood. A mixed model analysis was conducted to identify top nominally significantly differentially methylated genes, which were then used to perform a gene enrichment analysis. The linoleic acid metabolism pathway was significantly associated with post-deployment PTSD symptoms, after accounting for multiple comparisons. Linoleic acid has been linked to memory and immune related processes in previous research. Our findings suggest that differential methylation of linoleic acid pathway genes is associated with PTSD and thus may merit closer inspection as a possible mediator of resilience.

Efficacy of an internet-based written imagery rescripting intervention for survivors of institutional childhood abuse - A randomized controlled trial

BACKGROUND

Institutional childhood abuse can have a long-term impact on the survivors' mental health, however, treatment for this group is limited and not always accessible. An internet-based intervention was developed, with the aim to reduce psychological sequelae relating to institutional abuse.

OBJECTIVE

This study aimed to examine the efficacy of an online imagery rescripting intervention for survivors of institutional abuse, through assessing symptoms of depression, anxiety, PTSD, and CPTSD.

PARTICIPANTS AND SETTING

Seventy-two adult survivors of institutional childhood abuse in the former German Democratic Republic were randomized either to the intervention (n = 38) or to the waitlist condition (n = 34). The intervention consisted of 10 modules, based on written imagery rescripting, and involved asynchronous therapist contact.

METHODS

Primary outcomes included symptoms of depression (PHQ-9), anxiety (GAD-7), PTSD (ITQ), and CPTSD (ITQ DSO). The intervention condition was assessed at baseline, post-intervention, 3-, and 6-month follow-up.

RESULTS

Intention-to-treat analyses revealed a significant symptom reduction from baseline to post-assessment with medium to large effects for all main outcomes (d = 0.45 to d = 0.76), in favor of the intervention condition. Significant interactions between condition (intervention vs. wailist) and time (baseline vs. post-assesment) were revealed for all main outcomes (p < .001 to p = .024). The effects were maintained at follow-up.

CONCLUSIONS

The results suggest online writing-based imagery rescripting as a promising treatment option for adults formerly institutionalized in residential care. Future research is needed to explore its effectiveness for other groups of patients suffering from abuse and neglect.

Responding to concerns related to the measurement of ICD-11 complex posttraumatic stress disorder using the International Trauma Questionnaire

BACKGROUND

A recent study in this journal by Frewen et al. (2023) provided a critical analysis of the most widely used measure of ICD-11 Complex Posttraumatic Stress Disorder (CPTSD), the International Trauma Questionnaire (ITQ). The article was a thoughtful review and gave voice to several widely held concerns about the nature of CPTSD as it is represented in ICD-11 and measured by the ITQ. The primary concern expressed by Frewen et al. was that the symptom profile of ICD-11 CPTSD, as represented in the ITQ, is too simple and fails to provide adequate coverage of the construct.

OBJECTIVE

Despite its quality, the article included several misunderstandings about the nature of ICD-11 CPTSD, and the function of the ITQ, that we wish to clarify.

PARTICIPANTS

Not applicable.

SETTING

Not applicable.

RESULTS

In this article, we provide a description of what ICD-11 PTSD and CPTSD are, a review of the process that led to their inclusion in ICD-11, how the ITQ was developed and refined to measure these constructs. We then provide responses to several of the most important concerns raised by Frewen et al. CONCLUSIONS: We highlight the clinical utility of the ICD-11 descriptions of PTSD and CPTSD and discuss how the ITQ can be used as part of a suite of clinical assessments to accurately describe and understand common experiences of psychological distress that often result from exposure to traumatic life events.

[Posttraumatic stress disorder clinical guidelines and treatment standards: focus on the symptoms of the psychophysiological arousal]

The article describes the main diagnostic criteria and principles of posttraumatic stress disorder (PTSD) diagnostic with the consideration of risk factors and specific clinical features. The main biomarkers search trends and existing limitations are considered. The role of the psychophysiological arousal symptoms claster is highlighted in the clinical picture of PTSD as well as in connection with the main cluster of re-experiencing symptoms activation and slowing of sanogenesis process. The necessity of PTSD detection in somatic medicine is thoroughly described. The article presents therapeutic algorithms of the latest international and Russian PTSD treatment clinical guidelines based on the individual combination of psychotherapy and psychopharmacotherapy treatment choice. Additionally the accumulated during the last decades national clinical experience of the anxiety disorders treatment, including the symptoms of psychophysiological arousal is highlighted that determined the list of the recommended drugs indicating the evidence level, in the PTSD treatment standards and guidelines. The treatment choices possibilities with the consideration of different PTSD symptoms cluster expression and comorbid states and individual case distress level specific are presented. Main evidence based psychotherapeutic methods are described.

On the retrieval of earliest memories

Earliest memories were examined with respect to recollection type (i.e., remember-know), retrieval type (i.e., direct-generative), retrieval speed, and memory fluency (i.e., phonemic, semantic, and autobiographical). A total of 137 young adults (94 females; Mage = 20.47, SDage = 1.57) reported their earliest memories and specified their recollection and retrieval types for reported memories. They further dated their recollections by reporting the age at event, rated event characteristics and completed the phonemic, semantic, and autobiographical memory fluency tasks. Remembered and known earliest memories were similar in retrieval speed, but remembered memories were more prevalent. For retrieval type, direct and generative retrieval were similar in prevalence, but direct retrieval was faster in recalling the earliest memories. Directly retrieved memories were dated earlier than generated ones, but no such pattern in dating was observed for remember-know distinction. In terms of memory fluency, none of the three fluency tasks predicted the retrieval speed, recollection and retrieval type. For event characteristics, significant differences were observed only for vividness and rehearsal for both retrieval and recollection type. The present study is the first to explore recollection and retrieval type, retrieval speed, memory fluency together with dating and event characteristics in the context of earliest memories.

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.

Inducing emotionally negative nonbelieved memories using negative pictures

Memories that can be recalled but are no longer believed are termed nonbelieved memories. The current studies examined the creation of emotionally negative nonbelieved memories after viewing negatively valenced pictures. In both experiments, participants took part in two sessions. In Session 1, after being presented with a set of neutral and negative pictures, participants had to rate their emotional state. One week later, in Session 2, participants had to complete a recognition task to identify pictures that had appeared during the previous session. During this task, participants' memories for some pictures were challenged by telling them that their answers were incorrect in order to evoke nonbelieved memories. The experimental procedure was successful in creating nonbelieved memories in the participants. Specifically, in Experiment 1 (N = 35), we induced nonbelieved true memories for both negative and neutral pictures. We found a significant decrease in both belief and recollection after the challenge, with the change in belief being twice as large as the change in recollection. In Experiment 2 (N = 43), we successfully induced both nonbelieved true and false memories for negative pictures. Again, the reduction of belief was significantly greater than that of recollection. In general, participants evinced better memory for negative pictures, but following challenges people were just as likely to accept false social feedback and change their memories regarding other types of pictures. In both experiments, our challenges did not lead to notable changes in emotional state. In general, our findings show that emotionally negative nonbelieved memories can be successfully evoked in an experimental setting.

How do the sleep features that characterise depression impact memory?

Depression is associated with general sleep disturbance and abnormalities in sleep physiology. For example, compared with control subjects, depressed patients exhibit lower sleep efficiency, longer rapid eye movement (REM) sleep duration, and diminished slow-wave activity during non-REM sleep. A separate literature indicates that depression is also associated with many distinguishing memory characteristics, including emotional memory bias, overgeneral autobiographical memory, and impaired memory suppression. The sleep and memory features that hallmark depression may both contribute to the onset and maintenance of the disorder. Despite our rapidly growing understanding of the intimate relationship between sleep and memory, our comprehension of how sleep and memory interact in the aetiology of depression remains poor. In this narrative review, we consider how the sleep signatures of depression could contribute to the accompanying memory characteristics.

Specific topics, specific symptoms: linking the content of recurrent involuntary memories to mental health using computational text analysis

Researchers debate whether recurrent involuntary autobiographical memories (IAMs; memories of one's personal past retrieved unintentionally and repetitively) are pathological or ordinary. While some argue that these memories contribute to clinical disorders, recurrent IAMs are also common in everyday life. Here, we examined how the content of recurrent IAMs might distinguish between those that are maladaptive (related to worse mental health) versus benign (unrelated to mental health). Over two years, 6187 undergraduates completed online surveys about recurrent IAMs; those who experienced recurrent IAMs within the past year were asked to describe their memories, resulting in 3624 text descriptions. Using a previously validated computational approach (structural topic modeling), we identified coherent topics (e.g., "Conversations", "Experiences with family members") in recurrent IAMs. Specific topics (e.g., "Negative past relationships", "Abuse and trauma") were uniquely related to symptoms of mental health disorders (e.g., depression, PTSD), above and beyond the self-reported valence of these memories. Importantly, we also found that content in recurrent IAMs was distinct across symptom types (e.g., "Communication and miscommunication" was related to social anxiety, but not symptoms of other disorders), suggesting that while negative recurrent IAMs are transdiagnostic, their content remains unique across different types of mental health concerns. Our work shows that topics in recurrent IAMs-and their links to mental health-are identifiable, distinguishable, and quantifiable.

Neuropsychological Consequences of Massive Trauma: Implications and Clinical Interventions

Traumatic events, especially massive trauma resulting from catastrophic incidents, wars, or severe abuse can elicit significant neuropsychological alterations, with profound implications for cognitive, emotional, and behavioral functioning. This mini-review delineates the primary neural changes post-trauma and underscores the importance of timely neuropsychological and clinical interventions. Specific brain regions, including the amygdala and prefrontal cortex, undergo physiological changes that can lead to memory impairments, attention deficits, and emotional disturbances. PTSD, a commonly diagnosed condition post-trauma, exemplifies the intricate relationship between trauma and memory processing. Furthermore, the concept of neuroplasticity, the brain's inherent ability to adapt and rewire, offers hope for recovery. Current clinical interventions, such as cognitive behavioral therapy, mindfulness practices, and biofeedback, leverage this neuroplastic potential to foster healing. The review underscores the vital importance of early intervention to mitigate long-term neuropsychological impacts, emphasizing the role of timely and targeted clinical interventions. The synthesis of this knowledge is crucial for clinicians, allowing for informed therapeutic approaches that holistically address both the physiological and psychological dimensions of trauma.

A single case series of imagery rescripting of intrusive autobiographical memories in depression

BACKGROUND AND OBJECTIVES

Intrusive memories are a common feature of depression, thought to be related to the onset and maintenance of the disorder. Intrusive memories have been successfully targeted in posttraumatic stress disorder through imagery rescripting. Yet there is limited evidence for the effectiveness of this technique in depression. We examined whether 12 weekly sessions of imagery rescripting was associated with reductions in depression, rumination and intrusive memories in a sample of patients with major depressive disorder (MDD).

METHODS

Fifteen clinically depressed participants completed 12 weeks of imagery rescripting treatment while completing daily measures of depression symptoms, rumination and intrusive memory frequency.

RESULTS

There were significant reductions on pre-post treatment and daily assessment measures of depression symptoms, rumination and intrusive memories. Reductions in depression symptoms represented a large effect size, while 13 participants (87%) showed reliable improvement and 12 participants (80%) demonstrated clinically significant improvement and no longer met diagnostic criteria for MDD.

LIMITATIONS

The sample size was small, however the intensive daily assessment protocol ensured the viability of within-person analyses.

CONCLUSIONS

Imagery rescripting as a stand-alone intervention appears to be effective at reducing depression symptoms. Additionally, the treatment was well tolerated by clients and observed to overcome several traditional treatment barriers in this population.