Neurobehavioral moderators of post-traumatic stress disorder (PTSD) trajectories: study protocol of a prospective MRI study of recent trauma survivors

Post-treatment alterations in white matter integrity in PTSD: Effects on symptoms and functional connectivity a secondary analysis of an RCT

Post-traumatic stress disorder (PTSD) has been linked to altered communication within the limbic system, including reduced structural connectivity in the uncinate fasciculus (UNC; i.e., decreased fractional anisotropy; FA) and reduced resting-state functional connectivity (RSFC) between the hippocampus and ventromedial prefrontal cortex (vmPFC). Previous research has demonstrated attenuation of PTSD symptoms and alterations in RSFC following exposure-based psychotherapy. However, the relationship between changes in structural and functional connectivity patterns and PTSD symptoms following treatment remains unclear. To investigate this, we conducted a secondary analysis of data from a randomized clinical trial of intensive exposure therapy, evaluating alterations in UNC FA, hippocampus-vmPFC RSFC, and PTSD symptoms before (pre-treatment), 7 days after (post-treatment), and 30 days after (follow-up) the completion of therapy. Our results showed that post-treatment changes in RSFC were positively correlated with post-treatment and follow-up changes in UNC FA and that post-treatment changes in UNC FA were positively correlated with post-treatment and follow-up changes in PTSD symptoms. These findings suggest that early changes in functional connectivity are associated with sustained changes in anatomical connectivity, which in turn are linked to reduced PTSD symptom severity.

What Measures are Effective in Trauma Screening for Young Males in Custody? A COSMIN Systematic Review

Despite the available evidence identifying the high prevalence rates of potentially traumatic experiences in forensic populations, there is still a lack of evidence supporting the use of suitable assessment tools, especially for young males in custody. For services to identify, support, and offer trauma interventions to this cohort, practitioners require reliable and valid assessment tools. This systematic review (Open Science Framework registration: https://osf.io/r6hbk) identifies those tools able to provide valid, reliable, and comparable data for this cohort. Five electronic databases and gray literature were searched to identify relevant measures. Inclusion criteria: studies of tools to assess for trauma with males aged between 12 and 25 years-old in a custodial setting, any year of publication, and available in English. Exclusion criteria: studies that did not measure psychological trauma or include a standalone trauma scale, or report primary data. A three-step quality assessment method was used to evaluate the methodological quality and psychometric properties of the measures. Fourteen studies were selected for review (which included 12 measures). The studies sampled a total of approximately 1,768 male participants and an age range of 12 to 25 years. The studies reported on various types of psychometric evidence and due to the lack of homogeneity, a narrative synthesis was used to discuss, interpret, and evaluate each measure. The overall quality of the psychometric properties of the measures in this review showed that the currently available instruments for the assessment of trauma with young males in custody is limited but promising.

Neuroimaging of posttraumatic stress disorder in adults and youth: progress over the last decade on three leading questions of the field

Almost three decades have passed since the first posttraumatic stress disorder (PTSD) neuroimaging study was published. Since then, the field of clinical neuroscience has made advancements in understanding the neural correlates of PTSD to create more efficacious treatment strategies. While gold-standard psychotherapy options are available, many patients do not respond to them, prematurely drop out, or never initiate treatment. Therefore, elucidating the neurobiological mechanisms that define the disorder can help guide clinician decision-making and develop individualized mechanisms-based treatment options. To this end, this narrative review highlights progress made in the last decade in adult and youth samples on three outstanding questions in PTSD research: (1) Which neural alterations serve as predisposing (pre-exposure) risk factors for PTSD development, and which are acquired (post-exposure) alterations? (2) Which neural alterations can predict treatment outcomes and define clinical improvement? and (3) Can neuroimaging measures be used to define brain-based biotypes of PTSD? While the studies highlighted in this review have made progress in answering the three questions, the field still has much to do before implementing these findings into clinical practice. Overall, to better answer these questions, we suggest that future neuroimaging studies of PTSD should (A) utilize prospective longitudinal designs, collecting brain measures before experiencing trauma and at multiple follow-up time points post-trauma, taking advantage of multi-site collaborations/consortiums; (B) collect two scans to explore changes in brain alterations from pre-to-post treatment and compare changes in neural activation between treatment groups, including longitudinal follow up assessments; and (C) replicate brain-based biotypes of PTSD. By synthesizing recent findings, this narrative review will pave the way for personalized treatment approaches grounded in neurobiological evidence.

Assessment of memory deficits in psychiatric disorders: A systematic literature review

Memory deficits are observed across psychiatric disorders ranging from the prodrome of psychosis to common mental disorders such as anxiety, depression, and dissociative disorders. Memory deficits among patients recovering from psychiatric disorders could be directly related to the primary illness or secondary to the adverse effect of a treatment such as Electroconvulsive Therapy (ECT). The trouble in the meaningful integration of working-memory and episodic memory is the most commonly affected domain that requires routine assessments. An update on the recent trends of methods of assessment of memory deficits is the first step towards understanding and correcting these deficits to target optimum recovery. A systematic literature search was conducted from October 2018 to October 2022 to review the recent methods of assessment of memory deficits in psychiatric disorders. The definition of 'Memory deficit' was operationalized as 'selective processes of memory, commonly required for activities of daily living, and affected among psychiatric disorders resulting in subjective distress and dysfunction'. We included 110 studies, most of them being conducted in western countries on patients with schizophrenia. Other disorders included dementia and mild cognitive impairment. Brief Assessment of Cognition in Schizophrenia, Cambridge Automated Neuropsychological Test Battery, California Verbal Learning Test, Trail Making Test Part A and B, Rey Auditory Verbal Learning Test, Wechsler Memory Scale, Wechsler Adults Intelligence Scale-IV were the most common neuropsychological assessments used. Mini-Mental State Examination and Montreal Cognitive Assessment were the most common bedside assessment tools used while Squire Subjective Memory Questionnaire was commonly used to measure ECT-related memory deficits. The review highlights the recent developments in the field of assessment of memory deficits in psychiatric disorders. Findings recommend and emphasize routine assessment of memory deficits among psychiatric disorders in developing countries especially severe mental illnesses. It remains interesting to see the role of standardized assessments in diagnostic systems given more than a decade of research on memory deficits in psychiatric disorders.

Psychological flexibility, birth satisfaction and postnatal trauma symptoms in women with abnormally invasive placenta

BACKGROUND

Abnormally Invasive Placenta is an obstetric condition resulting in significant physical complications and shown to increase the likelihood of developing Post Traumatic Stress Disorder. Dissatisfaction with the care experienced increases the likelihood of Post Traumatic Stress Disorder. Psychological flexibility has been shown to reduce the severity of Post Traumatic Stress Disorder, but there is no research regarding either of these in women with Abnormally Invasive Placenta.

AIM

To investigate if there is a relationship between trauma experience in women with a diagnosis of Abnormally Invasive Placenta, psychological flexibility, and birth satisfaction.

METHOD

Using a retrospective questionnaire, 126 participants age range 18-45, comprising the Birth Satisfaction Scale Revised Indicator (BSS-RI), Impact of Events Scale Revised (IES-R) and Acceptance and Action Questionnaire (AAQ-2) was completed. A hierarchical regression assessed the predictive relationship of Psychological Flexibility and Birth Satisfaction on Trauma symptoms.

RESULTS

The relationship between Birth Satisfaction measured using the BSS-RI and likelihood of Post Traumatic Stress Disorder (IES-R) was not supported (r (124) = -.08, p = .36). Results did show that Psychological Flexibility (AAQ-2) correlated with Trauma Score (IES-R) (r (124) = .68, p < .001) in women who had experienced Abnormally Invasive Placenta and explained 45.3% of the variance.

CONCLUSION

The results suggest that Post Traumatic Stress Disorder in those with Abnormally Invasive Placenta is as high as 1 in 2 and can be mediated by psychological flexibility. In turn, this suggests that interventions to increase Psychological Flexibility in those with the diagnosis may reduce trauma symptom severity.Abbreviations: AAQ-2 - Acceptance and Action QuestionnaireAIP - Abnormally Invasive PlacentaBAME - Black Asian or other Minority EthnicitiesBSS-RI Birth Satisfaction Scale Revised IndicatorEPH - EPH Gestosis (Pre eclampsia/Eclampsia)DSM - Diagnostic Statical ManualIES-R - Impact of Events Scale RevisedPAS - Placenta Accreta SpectrumPTSD - Post Traumatic Stress Disorder.

Greater Early Posttrauma Activation in the Right Inferior Frontal Gyrus Predicts Recovery From Posttraumatic Stress Disorder Symptoms

BACKGROUND

Posttraumatic stress disorder (PTSD) has been associated with altered emotion processing and modulation in specific brain regions, i.e., the amygdala, insula, and medial prefrontal and anterior cingulate cortices. Functional alterations in these regions, recorded shortly after trauma exposure, may predict changes in PTSD symptoms.

METHODS

Survivors (N = 104) of a traumatic event, predominantly a motor vehicle accident, were included. Functional magnetic resonance imaging was used to assess brain activation 1, 6, and 14 months after trauma exposure (T1, T2, and T3, respectively). Participants performed the Shifted-attention Emotional Appraisal Task, which probes 3 affective processes: implicit emotional processing (of emotional faces), emotion modulation by attention shifting (away from these faces), and emotion modulation by appraisal (of the participants' own emotional response to these faces). We defined regions of interest based on task-related activations, extracted beta weights from these regions of interest, and submitted them to a series of analyses to examine relationships between neural activation and PTSD severity over the 3 time points.

RESULTS

At T1, a regression model containing activations in the left dorsolateral prefrontal cortex, bilateral inferior frontal gyrus (IFG), and medial prefrontal cortex during emotion modulation by appraisal significantly predicted change in PTSD symptoms. More specifically, greater right IFG activation at T1 was associated with greater reduction in symptom severity (T1-T3). Exploratory analysis also found that activation of the right IFG increased from T1 to T3.

CONCLUSIONS

The results suggest that greater early posttrauma activation during emotion appraisal in the right IFG, a region previously linked to cognitive control in PTSD, predicts recovery from PTSD symptoms.

Structural Neuroimaging of Hippocampus and Amygdala Subregions in Posttraumatic Stress Disorder: A Scoping Review

Numerous studies have explored the relationship between posttraumatic stress disorder (PTSD) and the hippocampus and the amygdala because both regions are implicated in the disorder's pathogenesis and pathophysiology. Nevertheless, those key limbic regions consist of functionally and cytoarchitecturally distinct substructures that may play different roles in the etiology of PTSD. Spurred by the availability of automatic segmentation software, structural neuroimaging studies of human hippocampal and amygdala subregions have proliferated in recent years. Here, we present a preregistered scoping review of the existing structural neuroimaging studies of the hippocampus and amygdala subregions in adults diagnosed with PTSD. A total of 3513 studies assessing subregion volumes were identified, 1689 of which were screened, and 21 studies were eligible for this review (total N = 2876 individuals). Most studies examined hippocampal subregions and reported decreased CA1, CA3, dentate gyrus, and subiculum volumes in PTSD. Fewer studies investigated amygdala subregions and reported altered lateral, basal, and central nuclei volumes in PTSD. This review further highlights the conceptual and methodological limitations of the current literature and identifies future directions to increase understanding of the distinct roles of hippocampal and amygdalar subregions in posttraumatic psychopathology.

Longitudinal volumetric evaluation of hippocampus and amygdala subregions in recent trauma survivors

The hippocampus and the amygdala play a central role in post-traumatic stress disorder (PTSD) pathogenesis. While alternations in volumes of both regions have been consistently observed in individuals with PTSD, it remains unknown whether these reflect pre-trauma vulnerability traits or acquired post-trauma consequences of the disorder. Here, we conducted a longitudinal panel study of adult civilian trauma survivors admitted to a general hospital emergency department (ED). One hundred eligible participants (mean age = 32.97 ± 10.97, n = 56 females) completed both clinical interviews and structural MRI scans at 1-, 6-, and 14-months after ED admission (alias T1, T2, and T3). While all participants met PTSD diagnosis at T1, only n = 29 still met PTSD diagnosis at T3 (a "non-Remission" Group), while n = 71 did not (a "Remission" Group). Bayesian multilevel modeling analysis showed robust evidence for smaller right hippocampus volume (P+ of ~0.014) and moderate evidence for larger left amygdala volume (P+ of ~0.870) at T1 in the "non-Remission" group, compared to the "Remission" group. Subregion analysis further demonstrated robust evidence for smaller volume in the subiculum and right CA1 hippocampal subregions (P+ of ~0.021-0.046) in the "non-Remission" group. No time-dependent volumetric changes (T1 to T2 to T3) were observed across all participants or between groups. Results support the "vulnerability trait" hypothesis, suggesting that lower initial volumes of specific hippocampus subregions are associated with non-remitting PTSD. The stable volume of all hippocampal and amygdala subregions does not support the idea of consequential, progressive, stress-related atrophy during the first critical year following trauma exposure.

Evaluating the Evidence for Brain-Based Biotypes of Psychiatric Vulnerability in the Acute Aftermath of Trauma

OBJECTIVE

The weak link between subjective symptom-based diagnostic methods for posttraumatic psychopathology and objectively measured neurobiological indices forms a barrier to the development of effective personalized treatments. To overcome this problem, recent studies have aimed to stratify psychiatric disorders by identifying consistent subgroups based on objective neural markers. Along these lines, a promising 2021 study by Stevens et al. identified distinct brain-based biotypes associated with different longitudinal patterns of posttraumatic symptoms. Here, the authors conducted a conceptual nonexact replication of that study using a comparable data set from a multimodal longitudinal study of recent trauma survivors.

METHODS

A total of 130 participants (mean age, 33.61 years, SD=11.21; 48% women) admitted to a general hospital emergency department following trauma exposure underwent demographic, clinical, and neuroimaging assessments 1, 6, and 14 months after trauma. All analyses followed the pipeline outlined in the original study and were conducted in collaboration with its authors.

RESULTS

Task-based functional MRI conducted 1 month posttrauma was used to identify four clusters of individuals based on profiles of neural activity reflecting threat and reward reactivity. These clusters were not identical to the previously identified brain-based biotypes and were not associated with prospective symptoms of posttraumatic psychopathology.

CONCLUSIONS

Overall, these findings suggest that the original brain-based biotypes of trauma resilience and psychopathology may not generalize to other populations. Thus, caution is warranted when attempting to define subtypes of psychiatric vulnerability using neural indices before treatment implications can be fully realized. Additional replication studies are needed to identify more stable and generalizable neuroimaging-based biotypes of posttraumatic psychopathology.

Use of Virtual Reality Techniques to Rehabilitate Military Veterans with Post-Traumatic Stress Disorder (Review)

Post-traumatic stress disorder (PTSD) is a mental and behavioral disorder developing after a traumatic event like participation in combat activities. Objective diagnosis of combat PTSD and effective rehabilitation of war veterans is a current multifaceted problem with particularly high social costs. This review aims to evaluate the potential of virtual reality technique used as exposure therapy tool (VRET) to rehabilitate combat veterans and service members with PTSD. The review was written following the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The final analysis includes 75 articles published in 2017-2022. VRET therapeutic effect mechanisms were examined along with protocols and scenarios of VRET combined with other interventions influencing PTSD treatment like pharmacotherapy, motion-assisted multi-modular memory desensitization and reconsolidation (3MDR), transcranial magnetic stimulation. The necessity is substantiated of psychophysiological measurements for objectification of PTSD clinical criteria and its dynamics during treatment. It was shown that inclusion of VRET to the package of PTSD rehabilitation interventions positively affects the results due to the enhanced effect of presence and greater experience personalization. Thus, VRET may be an effective, controlled, and cost-effective alternative for PTSD treatment in combatants, including those not responding to conventional therapy.

Right inferior frontal gyrus and ventromedial prefrontal activation during response inhibition is implicated in the development of PTSD symptoms

Background

Inhibition is a critical executive control process and an established neurobiological phenotype of PTSD, yet to our knowledge, no prospective studies have examined this using a contextual cue task that enables measurement of behavioural response and neural activation patterns across proactive and reactive inhibition.

Objective

The current longitudinal study utilised functional magnetic resonance imaging (fMRI) to examine whether deficits in proactive and reactive inhibition predicted PTSD symptoms six months after trauma.

Method

Twenty-three (65% males) medical patients receiving emergency medical care from a level 1 trauma centre were enrolled in the study and invited for an MRI scan 1-2-months post-trauma. PTSD symptoms were measured using self-report at scan and 6-months post-trauma. A stop-signal anticipation task (SSAT) during an fMRI scan was used to test whether impaired behavioural proactive and reactive inhibition, and reduced activation in right inferior frontal gyrus (rIFG), ventromedial prefrontal cortex (vmPFC), and bilateral hippocampus, were related to PTSD symptoms. We predicted that lower activation levels of vmPFC and rIFG during reactive inhibition and lower activation of hippocampus and rIFG during proactive inhibition would relate to higher 6-month PTSD symptoms.

Results

No significant associations were found between behavioural measures and 6-month PTSD. Separate linear regression analyses showed that reduced rIFG activation (F1,21 = 9.97, R2 = .32, p = .005) and reduced vmPFC activation (F1,21 = 5.19, R2 = .20, p = .03) significantly predicted greater 6-month PTSD symptoms; this result held for rIFG activation controlling for demographic variables and baseline PTSD symptoms (β = -.45, p = .04) and Bonferroni correction.

Conclusion

Our findings suggest that impaired rIFG and, to a lesser extent, vmPFC activation during response inhibition may predict the development of PTSD symptoms following acute trauma exposure. Given the small sample size, future replication studies are needed.

HIGHLIGHTS

Impaired inhibition may be an important risk factor for the development of PTSD following trauma, with less right inferior frontal gyrus and ventromedial prefrontal cortex activation during response inhibition predicting PTSD development.

Assessment of early neurocognitive functioning increases the accuracy of predicting chronic PTSD risk

Post-traumatic stress disorder (PTSD) is a protracted and debilitating consequence of traumatic events. Identifying early predictors of PTSD can inform the disorder's risk stratification and prevention. We used advanced computational models to evaluate the contribution of early neurocognitive performance measures to the accuracy of predicting chronic PTSD from demographics and early clinical features. We consecutively enrolled adult trauma survivors seen in a general hospital emergency department (ED) to a 14-month long prospective panel study. Extreme Gradient Boosting algorithm evaluated the incremental contribution to 14 months PTSD risk of demographic variables, 1-month clinical variables, and concurrent neurocognitive performance. The main outcome variable was PTSD diagnosis, 14 months after ED admission, obtained by trained clinicians using the Clinician-Administered PTSD Scale (CAPS). N = 138 trauma survivors (mean age = 34.25 ± 11.73, range = 18-64; n = 73 [53%] women) were evaluated 1 month after ED admission and followed for 14 months, at which time n = 33 (24%) met PTSD diagnosis. Demographics and clinical variables yielded a discriminatory accuracy of AUC = 0.68 in classifying PTSD diagnostic status. Adding neurocognitive functioning improved the discriminatory accuracy (AUC = 0.88); the largest contribution emanating from poorer cognitive flexibility, processing speed, motor coordination, controlled and sustained attention, emotional bias, and higher response inhibition, and recall memory. Impaired cognitive functioning 1-month after trauma exposure is a significant and independent risk factor for PTSD. Evaluating cognitive performance could improve early screening and prevention.

Neural Responsivity to Reward versus Punishment Shortly after Trauma Predicts Long-term Development of Post-Traumatic Stress Symptoms

BACKGROUND

Processing negative and positive valenced stimuli involve multiple brain regions including the amygdala and ventral striatum (VS). Post-Traumatic Stress Disorder (PTSD) is often associated with hyper-responsivity to negatively valenced, yet recent evidence also points to deficient positive valence functioning. It is yet unclear what is the relative contribution of such opposing valence processing shortly after trauma to the development of chronic PTSD.

METHODS

Neurobehavioral indicators of motivational positive vs. negative valence sensitivities were longitudinally assessed in 171 adults (87 females, age=34.19±11.47 years) at 1-, 6-, and 14-months following trauma exposure (TP1, TP2, TP3). Using a gambling fMRI paradigm, amygdala and VS functionality (activity and functional connectivity with the prefrontal cortex) in response to rewards vs. punishments were assessed with relation to PTSD severity at different time-points. The effect of valence processing was depicted behaviorally by the amount of risk taken to maximize reward.

RESULTS

PTSD severity at TP1 was associated with greater neural functionality in the amygdala (but not the VS) towards punishments vs. rewards, and fewer risky choices. PTSD severity at TP3 was associated with decreased neural functionality in both the VS and amygdala towards rewards vs. punishments at TP1 (but not with risky behavior). Explainable machine learning revealed the primacy of VS biased processing, over the amygdala, in predicting PTSD severity at TP3.

CONCLUSIONS

These results highlight the importance of biased neural responsivity to positive relative to negative motivational outcomes in PTSD development. Novel therapeutic strategies early after trauma may thus target both valence fronts.

Deep learning model of fMRI connectivity predicts PTSD symptom trajectories in recent trauma survivors

Early intervention following exposure to a traumatic life event could change the clinical path from the development of post traumatic stress disorder (PTSD) to recovery, hence the interest in early detection and underlying biological mechanisms involved in the development of post traumatic sequelae. We introduce a novel end-to-end neural network that employs resting-state and task-based functional MRI (fMRI) datasets, obtained one month after trauma exposure, to predict PTSD symptoms at one-, six- and fourteen-months after the exposure. FMRI data, as well as PTSD status and symptoms, were collected from adults at risk for PTSD development, after admission to emergency room following a traumatic event. Our computational method utilized a per-region encoder to extract brain regions embedding, which were subsequently updated by applying the algorithmic technique of pairwise attention. The affinities obtained between each pair of regions were combined to create a pairwise co-activation map used to perform multi-label classification. The results demonstrate that the novel method's performance in predicting PTSD symptoms, in a prospective manner, outperforms previous analytical techniques reported in the fMRI literature, all trained on the same dataset. We further show a high predictive ability for predicting PTSD symptom clusters and PTSD persistence. To the best of our knowledge, this is the first deep learning method applied on fMRI data with respect to prospective clinical outcomes, to predict PTSD status, severity and symptom clusters. Future work could further delineate the mechanisms that underlie such a prediction, and potentially improve single patient characterization.

Neighborhood disadvantage is associated with stable deficits in neurocognitive functioning in traumatically-injured adults

BACKGROUND

In trauma-exposed adults, the relationship between an individual's socioeconomic position (SEP) and post-traumatic stress disorder (PTSD) has been well demonstrated. One potential mechanism by which the stress associated with lower SEPs may impact trauma outcomes is through changes in neurocognition. In both healthy and clinical samples, area-level factors also appear to be independently related to neurocognition. Far less is known about how neighborhood socioeconomic disadvantage, may impact cognition in traumatically-injured adults. The current study employed hierarchical linear modeling to longitudinally investigate whether neighborhood disadvantage was associated with neurocognitive functioning in five domains: processing speed, sustained attention, controlled attention, cognitive flexibility, and response inhibition.

METHODS

One-hundred and ninety-five socioeconomically diverse traumatically-injured subjects (mean age = 32.8, 52.8% female) were recruited from an Emergency Department. Two-weeks, three-months, and six-months post-trauma, participants completed self-report measures and a computerized test battery to evaluate neurocognition. An Area Deprivation Index (ADI) score, a measure of a neighborhood's socioeconomic disadvantage, was derived from each participants' home address.

RESULTS

Greater neighborhood disadvantage was significantly related to lower scores in all domains. Results of hierarchical linear models revealed neighborhood disadvantage was significantly associated with processing speed, controlled attention, cognitive flexibility, and response inhibition across time, even after adjusting for individual annual household income, baseline PTSD symptoms, and previous adverse life experiences. This relationship was stable for all domains except sustained attention, which varied across time.

CONCLUSION

These findings indicate neighborhood disadvantage contributes uniquely to neurocognitive functioning and, for the majority of domains, these contributions are stable across time. The relationship between area-level variables and cognitive function may underlie individual vulnerability to developing psychiatric disorders. Future work should continue to examine the interaction between socioenvironmental stressors and PTSD symptoms longitudinally.

Social Robots for Supporting Post-traumatic Stress Disorder Diagnosis and Treatment

Post-Traumatic Stress Disorder (PTSD) is a severe psychiatric disorder with profound public health impact due to its high prevalence, chronic nature, accompanying functional impairment, and frequently occurring comorbidities. Early PTSD symptoms, often observed shortly after trauma exposure, abate with time in the majority of those who initially express them, yet leave a significant minority with chronic PTSD. While the past several decades of PTSD research have produced substantial knowledge regarding the mechanisms and consequences of this debilitating disorder, the diagnosis of and available treatments for PTSD still face significant challenges. Here, we discuss how novel therapeutic interventions involving social robots can potentially offer meaningful opportunities for overcoming some of the present challenges. As the application of social robotics-based interventions in the treatment of mental disorders is only in its infancy, it is vital that careful, well-controlled research is conducted to evaluate their efficacy, safety, and ethics. Nevertheless, we are hopeful that robotics-based solutions could advance the quality, availability, specificity and scalability of care for PTSD.

Multi-domain potential biomarkers for post-traumatic stress disorder (PTSD) severity in recent trauma survivors

Contemporary symptom-based diagnosis of post-traumatic stress disorder (PTSD) largely overlooks related neurobehavioral mechanisms and relies entirely on subjective interpersonal reporting. Previous studies associating biomarkers with PTSD have mostly used symptom-based diagnosis as the main outcome measure, disregarding the wide variability and richness of PTSD phenotypical features. Here, we aimed to computationally derive potential biomarkers that could efficiently differentiate PTSD subtypes among recent trauma survivors. A three-staged semi-unsupervised method ("3C") was used to firstly categorize individuals by current PTSD symptom severity, then derive clusters based on clinical features related to PTSD (e.g. anxiety and depression), and finally to classify participants' cluster membership using objective multi-domain features. A total of 256 features were extracted from psychometrics, cognitive functioning, and both structural and functional MRI data, obtained from 101 adult civilians (age = 34.80 ± 11.95; 51 females) evaluated within 1 month of trauma exposure. The features that best differentiated cluster membership were assessed by importance analysis, classification tree, and ANOVA. Results revealed that entorhinal and rostral anterior cingulate cortices volumes (structural MRI domain), in-task amygdala's functional connectivity with the insula and thalamus (functional MRI domain), executive function and cognitive flexibility (cognitive testing domain) best differentiated between two clusters associated with PTSD severity. Cross-validation established the results' robustness and consistency within this sample. The neural and cognitive potential biomarkers revealed by the 3C analytics offer objective classifiers of post-traumatic morbidity shortly following trauma. They also map onto previously documented neurobehavioral mechanisms associated with PTSD and demonstrate the usefulness of standardized and objective measurements as differentiating clinical sub-classes shortly after trauma.

Delayed behavioral and genomic responses to acute combined stress in zebrafish, potentially relevant to PTSD and other stress-related disorders: Focus on neuroglia, neuroinflammation, apoptosis and epigenetic modulation

Stress is a common trigger of stress-related illnesses, such as anxiety, phobias, depression and post-traumatic stress disorder (PTSD). Various animal models successfully reproduce core behaviors of these clinical conditions. Here, we develop a novel zebrafish model of stress (potentially relevant to human stress-related disorders), based on delayed persistent behavioral, endocrine and genomic responses to an acute severe 'combined' stressor. Specifically, one week after adult zebrafish were exposed to a complex combined 90-min stress, we assessed their behaviors in the novel tank and the light-dark box tests, as well as whole-body cortisol and brain gene expression, focusing on genomic biomarkers of microglia, astrocytes, neuroinflammation, apoptosis and epigenetic modulation. Overall, stressed fish displayed persistent anxiety-like behavior, elevated whole-body cortisol, as well as upregulated brain mRNA expression of genes encoding the glucocorticoid receptor, neurotrophin BDNF and its receptors (TrkB and P75), CD11b (a general microglial biomarker), COX-2 (an M1-microglial biomarker), CD206 (an M2-microglial biomarker), GFAP (a general astrocytal biomarker), C3 (an A1-astrocytal biomarker), S100α₁₀ (an A2-astrocytal biomarker), as well as pro-inflammatory cytokines IL-6, IL-1β, IFN-γ and TNF-α. Stress exposure also persistently upregulated the brain expression of several key apoptotic (Bax, Caspase-3, Bcl-2) and epigenetic genes (DNMT3a, DNMT3b, HAT1, HDAC4) in these fish. Collectively, the present model not only successfully recapitulates lasting behavioral and endocrine symptoms of clinical stress-related disorders, but also implicates changes in neuroglia, neuroinflammation, apoptosis and epigenetic modulation in long-term effects of stress pathogenesis in vivo.

Neuroanatomical Risk Factors for Posttraumatic Stress Disorder in Recent Trauma Survivors

BACKGROUND

Low hippocampal volume could serve as an early risk factor for posttraumatic stress disorder (PTSD) in interaction with other brain anomalies of developmental origin. One such anomaly may well be the presence of a large cavum septum pellucidum (CSP), which has been loosely associated with PTSD. We performed a longitudinal prospective study of recent trauma survivors. We hypothesized that at 1 month after trauma exposure the relation between hippocampal volume and PTSD symptom severity will be moderated by CSP volume, and that this early interaction will account for persistent PTSD symptoms at subsequent time points.

METHODS

One hundred seventy-one adults (87 women, average age 34.22 years [range, 18-65 years of age]) who were admitted to a general hospital's emergency department after a traumatic event underwent clinical assessment and structural magnetic resonance imaging within 1 month after trauma. Follow-up clinical evaluations were conducted at 6 (n = 97) and 14 (n = 78) months after trauma. Hippocampal and CSP volumes were measured automatically by FreeSurfer software and verified manually by a neuroradiologist (D.N.).

RESULTS

At 1 month after trauma, CSP volume significantly moderated the relation between hippocampal volume and PTSD severity (p = .026), and this interaction further predicted symptom severity at 14 months posttrauma (p = .018). Specifically, individuals with a smaller hippocampus and larger CSP at 1 month posttrauma showed more severe symptoms at 1 and 14 months after trauma exposure.

CONCLUSIONS

Our study provides evidence for an early neuroanatomical risk factors for PTSD, which could also predict the progression of the disorder in the year after trauma exposure. Such a simple-to-acquire neuroanatomical signature for PTSD could guide early management as well as long-term monitoring.