Post-traumatic stress disorder

Longitudinal analyses of the DNA methylome in deployed military servicemen identify susceptibility loci for post-traumatic stress disorder

In order to determine the impact of the epigenetic response to traumatic stress on post-traumatic stress disorder (PTSD), this study examined longitudinal changes of genome-wide blood DNA methylation profiles in relation to the development of PTSD symptoms in two prospective military cohorts (one discovery and one replication data set). In the first cohort consisting of male Dutch military servicemen (n=93), the emergence of PTSD symptoms over a deployment period to a combat zone was significantly associated with alterations in DNA methylation levels at 17 genomic positions and 12 genomic regions. Evidence for mediation of the relation between combat trauma and PTSD symptoms by longitudinal changes in DNA methylation was observed at several positions and regions. Bioinformatic analyses of the reported associations identified significant enrichment in several pathways relevant for symptoms of PTSD. Targeted analyses of the significant findings from the discovery sample in an independent prospective cohort of male US marines (n=98) replicated the observed relation between decreases in DNA methylation levels and PTSD symptoms at genomic regions in ZFP57, RNF39 and HIST1H2APS2. Together, our study pinpoints three novel genomic regions where longitudinal decreases in DNA methylation across the period of exposure to combat trauma marks susceptibility for PTSD.

Combat Experiences and their Relationship to Post-Traumatic Stress Disorder Symptom Clusters in UK Military Personnel Deployed to Afghanistan

The association of post-traumatic stress disorder (PTSD) symptom clusters with combat and other operational experiences among United Kingdom Armed Forces (UK AF) personnel who deployed to Afghanistan in 2009 were examined. Previous studies suggest that the risk of developing PTSD rises as combat exposure levels increase. To date, no UK research has investigated how specific classes of combat and operational experiences relate to PTSD symptom clusters. The current study was a secondary analysis of data derived from a two-arm cluster, randomized-controlled trial of a postdeployment operational stress-reduction intervention in deployed UK AF personnel. 2510 UK AF personnel provided combat exposure data and completed the PTSD checklist (civilian version) immediately post-deployment while 1635 of the original cohort completed further followed-up measures four to six months later. A 14-item combat experience scale was explored using principle component analysis, which yielded three main categories of experience: (1) violent combat, (2) proximity to wounding or death and (3) encountering explosive devices. The association of combat experience classes to PTSD 5-factor "dysphoric arousal" model (re-experiencing, avoidance, numbing, dysphoric-arousal and anxious-arousal symptoms) was assessed. Greater exposure to violent combat was predictive of re-experiencing and numbing symptoms, while proximity to wounding or death experiences were predictive of re-experiencing and anxious-arousal symptoms. Explosive device exposure was predictive of anxious-arousal symptoms. The present study suggests that categories of combat experience differentially impact on PTSD symptom clusters and may have relevance for clinicians treating military personnel following deployment.

Inactivation of the Ventrolateral Orbitofrontal Cortex Impairs Flexible Use of Safety Signals

Survival depends on adaptation to shifting environmental risks and opportunities. Regarding risks, the mechanisms which permit acquisition, recall, and flexible use of aversive associations is poorly understood. Drawing on the evidence that the orbital frontal cortex is critical to integrating outcome expectancies with flexible appetitive behavioral responses, we hypothesized that OFC would contribute to behavioral flexibility within an aversive learning domain. We introduce a fear conditioning procedure in which adult male rats were presented with shock-paired conditioned stimulus (CS+) or a safety cue (CS-). In a recall test, rats exhibit greater freezing to the CS+ than the CS-. Temporary inactivation of the ventrolateral OFC with muscimol prior to conditioning did not affect later discrimination, but inactivation after learning and prior to recall impaired discrimination between safety and danger cues. This result complements prior research in the appetitive domain and suggests that the OFC plays a general role in behavioral flexibility regardless of the valence of the CS.

Adversity and Resilience Are Associated with Outcome after Mild Traumatic Brain Injury in Military Service Members

The objective of this study was to assess the associations between resilience, adversity, post-concussion symptoms, and post-traumatic stress symptom reporting after mild traumatic brain injury (mTBI). We hypothesized that resilience would be associated with less symptom reporting, and adversity would be associated with greater symptom reporting. This was a cross-sectional study of retrospective data collected for an ongoing TBI repository. United States military service members who screened positive for mTBI during a primary care visit completed the Trauma History Screen (THS), Connor-Davidson Resilience Scale (CD-RISC), Neurobehavioral Symptom Inventory (NSI), and post-traumatic stress disorder (PTSD) Checklist-Civilian Version (PCL-C). Data collected from February 2015 to August 2016 were used for the present study. Only participants with complete data for the above measures were included, yielding a sample size of 165 participants. Adversity (THS) and resilience (CD-RISC) scores were each correlated significantly with post-concussion (NSI) and traumatic stress (PCL-C) total and subscale scores in the hypothesized direction. Interactions between adversity and resilience were absent for all measures except the NSI sensory subscale. Four traumatic event types were significantly associated positively with most NSI and PCL-C total and subscale scores, but the age at which traumatic events were first experienced showed few and mixed significant associations. In conclusion, resilience and adversity were significantly associated with symptom endorsement after mTBI. Screening for cumulative adversity may identify individuals at greater risk of developing persistent post-concussion symptoms and/or PTSD, and interventions that increase resilience may reduce symptom severity.

Moral injury process and its psychological consequences among Israeli combat veterans

OBJECTIVES

We aim to examine the link between exposure to potentially morally injurious events (PMIEs) and posttraumatic stress disorder symptoms (PTSS). We also aim to explore the mediating roles of depressive attributions, trauma-related guilt and shame, and self-disgust in the relationship between PMIEs and PTSS among combat veterans.

METHOD

A volunteers' sample of 191 Israeli combat veterans responded to self-report questionnaires in a cross-sectional design study.

RESULTS

More than one-fifth of the sample reported experiencing PMIEs but only betrayal based experience was related to PTSS. Importantly, betrayal based experience was associated with depressive attributions which increased the level of trauma-related distressing guilt, intrinsic shame and self-disgust, which in turn were associated with high levels of PTSS.

CONCLUSIONS

PMIEs, and especially betrayal based experiences, are related to PTSS among Israeli veterans. Depressive attributions, trauma-related distressing guilt, intrinsic shame, and self-disgust might serve as possible mechanisms for the links between PMIEs and PTSS.

Factors associated with persistent posttraumatic stress disorder among U.S. military service members and veterans

BACKGROUND

Posttraumatic stress disorder (PTSD) can have long-term and far-reaching impacts on health and social and occupational functioning. This study examined factors associated with persistent PTSD among U.S. service members and veterans.

METHODS

Using baseline and follow-up (2001-2013) questionnaire data collected approximately every 3 years from the Millennium Cohort Study, multivariable logistic regression was conducted to determine factors associated with persistent PTSD. Participants included those who screened positive for PTSD using the PTSD Checklist-Civilian Version at baseline (N = 2409). Participants were classified as having remitted or persistent PTSD based on screening negative or positive, respectively, at follow-up.

RESULTS

Almost half of participants (N = 1132; 47%) met criteria for persistent PTSD at the first follow-up; of those, 804 (71%) also screened positive for PTSD at the second follow-up. Multiple factors were independently associated with persistent PTSD in an adjusted model at the first follow-up, including older age, deployment with high combat exposure, enlisted rank, initial PTSD severity, depression, history of physical assault, disabling injury/illness, and somatic symptoms. Among those with persistent PTSD at the first follow-up, additional factors of less sleep, separation from the military, and lack of social support were associated with persistent PTSD at the second follow-up.

CONCLUSIONS

Combat experiences and PTSD severity were the most salient risk factors for persistent PTSD. Comorbid conditions, including injury/illness, somatic symptoms, and sleep problems, also played a significant role and should be addressed during treatment. The high percentage of participants with persistent PTSD supports the need for more comprehensive and accessible treatment, especially after separation from the military.

Mindfulness-based treatments for posttraumatic stress disorder: a review of the treatment literature and neurobiological evidence

Mindfulness-based treatments for posttraumatic stress disorder (PTSD) have emerged as promising adjunctive or alternative intervention approaches. A scoping review of the literature on PTSD treatment studies, including approaches such as mindfulness-based stress reduction, mindfulness-based cognitive therapy and metta mindfulness, reveals low attrition with medium to large effect sizes. We review the convergence between neurobiological models of PTSD and neuroimaging findings in the mindfulness literature, where mindfulness interventions may target emotional under- and overmodulation, both of which are critical features of PTSD symptomatology. Recent emerging work indicates that mindfulness-based treatments may also be effective in restoring connectivity between large-scale brain networks among individuals with PTSD, including connectivity between the default mode network and the central executive and salience networks. Future directions, including further identification of the neurobiological mechanisms of mindfulness interventions in patients with PTSD and direct comparison of these interventions to first-line treatments for PTSD are discussed.

Challenges Associated With the Civilian Reintegration of Soldiers With Chronic PTSD: A New Approach Integrating Psychological Resources and Values in Action Reappropriation

Background: In light of the psychological changes in an individual suffering from chronic Posttraumatic Stress Disorder (PTSD), questions are being raised in order to understand and facilitate recovery and a return to work. This is particularly challenging for soldiers suffering from chronic PTSD, who are often young individuals suffering from moral conflicts. A French military rehabilitation program proposes the broadening of the relationships between recovery and reintegration by incorporating approaches from the field of positive psychology for soldiers with chronic PTSD. The aim of the study was to evaluate (i) the psychological resources which remain sustainable for these trauma exposed soldiers according to their PTSD symptoms, (ii) the dynamics of resource reappropriation after the military rehabilitation program, which focuses on values in action (VIA) as character strengths, and (iii) how these resources and their reappropriation facilitate civilian professional reintegration. Method: We conducted a prospective study with 56 trauma exposed soldiers with a clinical diagnosis of chronic PTSD. PTSD severity and psychological resources (optimism, mindfulness, well-being, motivation, self-esteem, and VIA) were assessed before and after the rehabilitation program. After the identification of resource profiles, we analyzed the impact of the program on resource levels and successful reintegration into a civilian job. Results: 3 profiles were identified based on the psychological resources of the soldiers. Profiles 1, 2, and 3 differed in terms of clinical severity (PCL5). Profile 1 exhibited both the highest level of resources and the lowest clinical severity of PTSD but did not modify its resources after the intervention program when compared to profile 3. Profile 3 was characterized by the lowest level of resources, the highest clinical severity of PTSD and the highest reappropriation in all VIAs. This profile was associated with the highest rate of reintegration success 1 year after the intervention. Conclusions: This paper aims to broaden the relationship between recovery and reintegration by incorporating approaches from the field of positive psychology for soldiers with PTSD. VIA appears to be an important factor for reintegration. Our results highlight the importance of taking into account the existing needs of the patient and the optimization of the modalities of individual, collective, and institutional rehabilitation for patients suffering from PTSD in order to better understand the dynamics of the recovery process of a chronically afflicted individual.

Cerebellar and prefrontal cortical alterations in PTSD: structural and functional evidence

BACKGROUND

Neuroimaging studies have revealed that disturbances in network organization of key brain regions may underlie cognitive and emotional dysfunction in posttraumatic stress disorder (PTSD). Examining both brain structure and function in the same population may further our understanding of network alterations in PTSD.

METHODS

We used tensor-based morphometry (TBM) and intrinsic connectivity distribution (ICD) to identify regions of altered volume and functional connectivity in unmedicated individuals with PTSD (n=21) and healthy comparison (HC) participants (n=18). These regions were then used as seeds for follow-up anatomical covariance and functional connectivity analyses.

RESULTS

Smaller volume in the cerebellum and weaker structural covariance between the cerebellum seed and middle temporal gyrus were observed in the PTSD group. Individuals with PTSD also exhibited lower whole-brain connectivity in the cerebellum, dorsolateral prefrontal cortex (dlPFC) and medial prefrontal cortex (mPFC). Functional connectivity in the cerebellum and grey matter volume in the dlPFC were negatively correlated with PTSD severity as measured by the DSM-5 PTSD checklist (PCL-5; r= -.0.77, r=-0.79). Finally, seed connectivity revealed weaker connectivity within nodes of the central executive network (right and left dlPFC), and between nodes of the default mode network (mPFC and cerebellum) and the supramarginal gyrus, in the PTSD group.

CONCLUSION

We demonstrate structural and functional alterations in PTSD converging on the PFC and cerebellum. Whilst PFC alterations are relatively well established in PTSD, the cerebellum has not generally been considered a key region in PTSD. Our findings add to a growing evidence base implicating cerebellar involvement in the pathophysiology of PTSD.

Integrating Endocannabinoid Signaling and Cannabinoids into the Biology and Treatment of Posttraumatic Stress Disorder

Exposure to stress is an undeniable, but in most cases surmountable, part of life. However, in certain individuals, exposure to severe or cumulative stressors can lead to an array of pathological conditions including posttraumatic stress disorder (PTSD), characterized by debilitating trauma-related intrusive thoughts, avoidance behaviors, hyperarousal, as well as depressed mood and anxiety. In the context of the rapidly changing political and legal landscape surrounding use of cannabis products in the USA, there has been a surge of public and research interest in the role of cannabinoids in the regulation of stress-related biological processes and in their potential therapeutic application for stress-related psychopathology. Here we review the current state of knowledge regarding the effects of cannabis and cannabinoids in PTSD and the preclinical and clinical literature on the effects of cannabinoids and endogenous cannabinoid signaling systems in the regulation of biological processes related to the pathogenesis of PTSD. Potential therapeutic implications of the reviewed literature are also discussed. Finally, we propose that a state of endocannabinoid deficiency could represent a stress susceptibility endophenotype predisposing to the development of trauma-related psychopathology and provide biologically plausible support for the self-medication hypotheses used to explain high rates of cannabis use in patients with trauma-related disorders.

Minocycline Attenuates Stress-Induced Behavioral Changes via Its Anti-inflammatory Effects in an Animal Model of Post-traumatic Stress Disorder

Accumulating evidences have suggested that anxiety-like behavior and impairment of learning and memory are key symptoms of post-traumatic stress disorder (PTSD), and pharmacological treatment can ameliorate anxiety and cognitive impairments. Recent studies have shown that minocycline exhibits anxiolytic effects. The aims of the present study were to determine whether minocycline administration would alter anxiety-like behavior and cognitive deficits induced by inescapable foot shock (IFS) and to explore the underlying mechanisms. Male Wistar rats were exposed to the IFS protocol for a period of 6 days to induce PTSD. The PTSD-like behavior was tested using the open field test, elevated plus maze test, and Morris water maze test. The effects of minocycline on pro-inflammatory cytokines, activation of microglia, and NF-κB in the PFC and hippocampus were also examined. Treatment with minocycline significantly reversed the IFS induced behavioral and cognitive parameters (impaired learning and memory function) in stressed rats. Additionally, IFS was able to increase pro-inflammatory cytokines, activate microglia, and enhance NF-κB levels, while minocycline significantly reversed these alterations. Taken together, our results suggest that the anxiolytic effect of minocycline is related to its ability to decrease the levels of pro-inflammatory cytokines and inhibit activation of microglia and NF-κB in the PFC and hippocampus.

Adverse Childhood Experiences and the Consequences on Neurobiological, Psychosocial, and Somatic Conditions Across the Lifespan

Introduction: Adverse childhood experiences (ACE) such as sexual and physical abuse or neglect are frequent in childhood and constitute a massive stressor with long-lasting adverse effects on the brain, mental and physical health.The aim of this qualitative review is to present a concise overview of the present literature on the impact of ACE on neurobiology, mental and somatic health in later adulthood. Methods: The authors reviewed the existing literature on the impact of ACE on neurobiology, mental and somatic health in later adulthood and summarized the results for a concise qualitative overview. Results: In adulthood, the history of ACE can result in complex clinical profiles with several co-occurring mental and somatic disorders such as posttraumatic stress disorder, depression, borderline personality disorder, obesity and diabetes. Although a general stress effect in the development of the disorders and neural alterations can be assumed, the role of type and timing of ACE is of particular interest in terms of prevention and treatment of ACE-related mental and somatic conditions. It has been suggested that during certain vulnerable developmental phases the risk for subsequent ACE-related disorders is increased. Moreover, emerging evidence points to sensitive periods and specificity of ACE-subtypes in the development of neurobiological alterations, e.g., volumetric and functional changes in the amygdala and hippocampus. Conclusion: Longitudinal studies are needed to investigate complex ACE-related characteristics and mechanisms relevant for mental and somatic disorders by integrating state of the art knowledge and methods. By identifying and validating psychosocial and somatic risk factors and diagnostic markers one might improve the development of innovative somatic and psychological treatment options for individuals suffering from ACE-related disorders.

Meta-analysis of the interaction between serotonin transporter promoter variant, stress, and posttraumatic stress disorder

Exposure to stress predicts the occurrence of posttraumatic stress disorder (PTSD) in individuals harboring the serotonin transporter promoter variant 5-HTTLPR. We carried out a meta-analysis of studies investigating the interaction between 5-HTTLPR, stress, and PTSD to clarify the interrelatedness of these factors. We reviewed all relevant studies published in English before May 2016. The Lipták-Stouffer z-score method for meta-analysis was applied to combined data. The z score was separately calculated for the stressful life events, childhood adversity, bi- and triallelic loci, and cross-sectional and longitudinal studies subgroups. A total of 14 studies with 15,883 subjects met our inclusion criteria. We found strong evidence that the presence of 5-HTTLPR influenced the relationship between stress and PTSD (P = 0.00003), with the strongest effects observed in the cross-sectional and longitudinal groups (P = 0.01 and 2.0 × 10-6, respectively). Stressful life events and childhood adversity separately interacted with 5-HTTLPR in PTSD (P = 2.0 × 10-8 and 0.003, respectively). When the studies were stratified by locus classification, the evidence was stronger for the triallelic (P = 4.0 × 10-8) than for the biallelic (P = 0.054) locus subgroup. There was strong evidence that 5-HTTLPR influences the relationship between stress and PTSD.

Dynamic causal modeling in PTSD and its dissociative subtype: Bottom-up versus top-down processing within fear and emotion regulation circuitry

OBJECTIVE

Posttraumatic stress disorder (PTSD) is associated with decreased top-down emotion modulation from medial prefrontal cortex (mPFC) regions, a pathophysiology accompanied by hyperarousal and hyperactivation of the amygdala. By contrast, PTSD patients with the dissociative subtype (PTSD + DS) often exhibit increased mPFC top-down modulation and decreased amygdala activation associated with emotional detachment and hypoarousal. Crucially, PTSD and PTSD + DS display distinct functional connectivity within the PFC, amygdala complexes, and the periaqueductal gray (PAG), a region related to defensive responses/emotional coping. However, differences in directed connectivity between these regions have not been established in PTSD, PTSD + DS, or controls.

METHODS

To examine directed (effective) connectivity among these nodes, as well as group differences, we conducted resting-state stochastic dynamic causal modeling (sDCM) pairwise analyses of coupling between the ventromedial (vm)PFC, the bilateral basolateral and centromedial (CMA) amygdala complexes, and the PAG, in 155 participants (PTSD [n = 62]; PTSD + DS [n = 41]; age-matched healthy trauma-unexposed controls [n = 52]).

RESULTS

PTSD was characterized by a pattern of predominant bottom-up connectivity from the amygdala to the vmPFC and from the PAG to the vmPFC and amygdala. Conversely, PTSD + DS exhibited predominant top-down connectivity between all node pairs (from the vmPFC to the amygdala and PAG, and from the amygdala to the PAG). Interestingly, the PTSD + DS group displayed the strongest intrinsic inhibitory connections within the vmPFC.

CONCLUSIONS

These results suggest the contrasting symptom profiles of PTSD and its dissociative subtype (hyper- vs. hypo-emotionality, respectively) may be driven by complementary changes in directed connectivity corresponding to bottom-up defensive fear processing versus enhanced top-down regulation. Hum Brain Mapp 38:5551-5561, 2017. © 2017 Wiley Periodicals, Inc.

Altered stress system reactivity after pediatric injury: Relation with post-traumatic stress symptoms

Injury is the leading cause of death and disability in childhood. Injured children are at high risk for developing alterations in stress response systems and post-traumatic stress symptoms (PTSS) that may compromise long-term physical and psychological health. In a prospective, observational cohort study, we examined individual differences in, and correlates of, stress-reactivity of the hypothalamic-pituitary-adrenal axis (HPA; salivary cortisol) and autonomic nervous system (ANS; salivary alpha amylase, sAA) following pediatric injury. Participants were 8-15 years of age and hospitalized for traumatic brain injury (TBI; n=55; M age=13.9 yrs; 40 males) or extracranial injury (EI; n=29; M age 12.3 yrs, 20 males) following vehicular accidents. Six months post-injury, saliva was collected before and after the Trier Social Stress Test and later assayed for cortisol and sAA. Relative to a healthy non-injured comparison group (n=33; M age=12.5 yrs, 16 males), injured children (ages 8-12 years), but not adolescents (ages 13-15 yrs), had higher cortisol levels; regardless of age, injured participants showed dampened cortisol reactivity to social evaluative threat. Compared to participants with EI, children with TBI had elevated cortisol and adolescents had elevated sAA. With respect to PTSS, individual differences in sAA were negatively correlated with avoidance in the TBI group and positively correlated with emotional numbing within the EI group. Importantly, psychological and neurobiological sequelae were weakly related to injury severity. Given the high prevalence of pediatric injury, these sequelae affect many children and represent a significant public health concern. Consequently, surveillance of post-traumatic sequelae should include the full spectrum of injury severity. Monitoring the activity, reactivity, and regulation of biological systems sensitive to environmental insults may advance our understanding of individual differences in sequelae and adaptation following traumatic pediatric injury.

A systematic review of the usefulness of pre-employment and pre-duty screening in predicting mental health outcomes amongst emergency workers

Despite a lack of proven efficacy, pre-employment or pre-duty screening, which alleges to test for vulnerability to PTSD and other mental health disorders, remains common amongst emergency services. This systematic review aimed to determine the usefulness of different factors in predicting mental disorder amongst emergency workers and to inform practice regarding screening procedures. Systematic searches were conducted in MEDLINE, PsycINFO and EMBASE to identify cohort studies linking pre-employment or pre-duty measures in first responders with later mental health outcomes. Possible predictors of poor mental health were grouped into six categories and their overall level of evidence was assessed. Twenty-one prospective cohort studies were identified. Dynamic measures including physiological responses to simulated trauma and maladaptive coping styles (e.g. negative self-appraisal) had stronger evidence as predictors of vulnerability in first responders than more traditional static factors (e.g. pre-existing psychopathology). Personality factors (e.g. trait anger) had moderate evidence for predictive power. Based on the evidence reviewed, however, we are unable to provide emergency services with specific information to enhance their current personnel selection. The results indicate that pre-duty screening protocols that include personality assessments and dynamic measures of physiological and psychological coping strategies may be able to identify some personnel at increased risk of mental health problems. However, further longitudinal research is required in order to provide meaningful guidance to employers on the overall utility of either pre-employment or pre-duty screening. In particular, research examining the sensitivity, specificity and positive predictive values of various screening measures is urgently needed.

Risk factors for concurrent suicidal ideation and violent impulses in military veterans

Suicide and violence are significant problems in a subset of Iraq/Afghanistan-era veterans. This study investigates how posttraumatic stress disorder (PTSD) and resilience in veterans are associated with suicidal ideation and violent impulses while controlling for known covariates of both adverse outcomes. Structured clinical interviews were conducted of N = 2,543 Iraq/Afghanistan-era U.S. veterans. Compared with veterans denying suicidal ideation or violent impulses (n = 1,927), veterans endorsing both (n = 171) were more likely to meet diagnostic criteria for PTSD, report childhood abuse, combat exposure, physical pain symptoms, and drug misuse, and less likely to endorse self-direction/life purpose. Veterans reporting concurrent suicidal ideation and violent impulses had higher odds of misusing drugs and reporting pain symptoms relative to veterans reporting suicidal ideation only (n = 186) and had lower odds of endorsing self-direction/life purpose compared with veterans reporting violent impulses only (n = 259). The findings underscore the importance of examining drug abuse, physical pain symptoms, and self-direction/life purpose, as well as PTSD and history of trauma, in the context of clinical assessment and empirical research aimed at optimizing risk management of suicide and violence in military veterans. (PsycINFO Database Record

Heart rate-based window segmentation improves accuracy of classifying posttraumatic stress disorder using heart rate variability measures

OBJECTIVE

Heart rate variability (HRV) characterizes changes in autonomic nervous system function and varies with posttraumatic stress disorder (PTSD). In this study we developed a classifier based on heart rate (HR) and HRV measures, and improved classifier performance using a novel HR-based window segmentation.

APPROACH

Single-channel ECG data were collected from 23 subjects with current PTSD, and 25 control subjects with no history of PTSD over 24 h. RR intervals were derived from these data, cleaned, and used to calculate HR and HRV metrics. These metrics were used as features in a logistic regression classifier. Performance was assessed via repeated random sub-sampling validation. To reduce noise and activity-related effects, we calculated features from five non-overlapping ten-minute quiescent segments of RR intervals defined by lowest HR, as well as random ten-minute segments as a control.

MAIN RESULTS

Using a combination of the four most predictive features derived from quiescent segments we achieved a median area under the receiver operating curve (AUC) of 0.86 on out-of-sample test set data. This was significantly higher than the AUC using 24 h of data (0.72) or random segments (0.67).

SIGNIFICANCE

These results demonstrate our segmentation approach improves the classification of PTSD from HR and HRV measures, and suggest the potential for tracking PTSD illness severity via objective physiological monitoring. Future studies should prospectively evaluate if classifier output changes significantly with worsening or effective treatment of PTSD.

Assessing PTSD in the military: Validation of a scale distributed to Danish soldiers after deployment since 1998

Since 1998, soldiers deployed to war zones with the Danish Defense (≈31,000) have been invited to fill out a questionnaire on post-mission reactions. This provides a unique data source for studying the psychological toll of war. Here, we validate a measure of PTSD-symptoms from the questionnaire. Soldiers from two cohorts deployed to Afghanistan with the International Security Assistance Force (ISAF) in 2009 (ISAF7, N = 334) and 2013 (ISAF15, N = 278) filled out a standard questionnaire (Psychological Reactions following International Missions, PRIM) concerning a range of post-deployment reactions including symptoms of PTSD (PRIM-PTSD). They also filled out a validated measure of PTSD-symptoms in DSM-IV, the PTSD-checklist (PCL). We tested reliability of PRIM-PTSD by estimating Cronbach's alpha, and tested validity by correlating items, clusters, and overall scale with corresponding items in the PCL. Furthermore, we conducted two confirmatory factor analytic models to test the factor structure of PRIM-PTSD, and tested measurement invariance of the selected model. Finally, we established a screening and a clinical cutoff score by application of ROC analysis. We found high internal consistency of the PRIM-PTSD (Cronbach's alpha = 0.88; both cohorts), strong item-item (0.48-0.83), item-cluster (0.43-0.72), cluster-cluster (0.71-0.82) and full-scale (0.86-0.88) correlations between PRIM-PTSD and PCL. The factor analyses showed adequate fit of a one-factor model, which was also found to display strong measurement invariance across cohorts. ROC curve analysis established cutoff scores for screening (sensitivity = 1, specificity = 0.93) and clinical use (sensitivity = 0.71, specificity = 0.98). In conclusion, we find that PRIM-PTSD is a valid measure for assessing PTSD-symptoms in Danish soldiers following deployment.

Does the Vulnerability Paradox in PTSD Apply to Women and Men? An Exploratory Study

Recent research suggests that greater country vulnerability is associated with a decreased, rather than increased, risk of mental health problems. Because societal parameters may have gender-specific implications, our objective was to explore whether the "vulnerability paradox" equally applies to women and men. Lifetime posttraumatic stress disorder (PTSD) prevalence data for women and men were retrieved from 11 population studies (N = 57,031): conducted in Australia, Brazil, Canada, France, Lebanon, Mexico, Netherlands, Portugal, Sweden, Switzerland, and the United States. We tested statistical models with vulnerability, gender, and their interaction as predictors. The average lifetime PTSD prevalence in women was at least twice as high as it was in men and the vulnerability paradox existed in the prevalence data for women and men (R² = .70). We could not confirm the possibility that gender effects are modified by socioeconomic and cultural country characteristics. Issues of methodology, language, and cultural validity complicate international comparisons. Nevertheless, this international sample points at a parallel paradox: The vulnerability paradox was confirmed for both women and men. The absence of a significant interaction between gender and country vulnerability implies that possible explanations for the paradox at the country-level do not necessarily require gender-driven distinction.

Genetic approaches for the study of PTSD: Advances and challenges

Post-traumatic stress disorder (PTSD) is a highly debilitating stress and anxiety-related disorder that occurs in response to specific trauma or abuse. Genetic risk factors may account for up to 30-40% of the heritability of PTSD. Understanding the gene pathways that are associated with PTSD, and how those genes interact with the fear and stress circuitry to mediate risk and resilience for PTSD will enable the development of targeted therapies to prevent the occurrence of or decrease the severity of this complex multi-gene disorder. This review will summarize recent research on genetic approaches to understanding PTSD risk and resilience in human populations, including candidate genes and their epigenetic modifications, genome-wide association studies and neural imaging genetics approaches. Despite challenges faced within this field of study such as inconsistent results and replications, genetic approaches still offer exciting opportunities for the identification and development of novel therapeutic targets and therapies in the future.

The Need to Take a Staging Approach to the Biological Mechanisms of PTSD and its Treatment

Despite the substantial body of neurobiological research, no specific drug target has been developed to treat PTSD and there are substantial limitations with the available interventions. We propose that advances are likely to depend on the development of better classification of the heterogeneity of PTSD using a staging approach of disease. A primary rationale for staging is to highlight the probability that distinct therapeutic approaches need to be utilised according to the degree of biological progression of the disorder. Prospective studies, particularly of military populations, provide substantial evidence about the emerging biological abnormalities that precede the full-blown disorder. These need to be targeted with tailored interventions to prevent disease progression. Equally, the neurobiology of chronic unremitting PTSD needs to be differentiated from the acute disorder which emerges across a spectrum of severity, and this range of presentations correspondingly needs to be addressed with differing therapeutic strategies. The staging approach also needs to take account of the range of somatic pathological outcomes that are being identified as a consequence of traumatic stress exposure. PTSD should be conceptualised as a systemic disorder underpinned a range of biological dysregulation, including metabolic and altered immune function, reflected in the increased rates of cardiovascular and autoimmune disease. The effectiveness of novel treatments needs to be judged across their effectiveness in addressing the spectrum of trauma-related pathology.

Posttraumatic Stress Disorder and Related Disorders among Female Yazidi Refugees following Islamic State of Iraq and Syria Attacks-A Case Series and Mini-Review

Following the severe attacks by the so-called "Islamic State of Iraq and Syria" on the Yazidi population, which started in summer 2014, the state government of Baden-Württemberg, Germany, funded a Special-Quota Project to bring 1,000 very ill or left-behind women and children who were being held hostage to 22 cities and towns in Baden-Württemberg to receive integrated care. Here, we report for the first time on the cases of four Yazidi women living in Ulm, Germany, focusing on the clinically observed and psychometrically assessed mental phenomena or disorders. Our primary aim was to explore what International Classification of Diseases, 10th Revision diagnoses are present in this population. Although highly traumatized, these women were suffering primarily from adjustment disorder rather than posttraumatic stress disorder according to official classification systems. Despite their symptoms of depression and anxiety, the women's responses to self-assessment questionnaires provided no evidence of compulsion, somatization, or eating disorders. The results suggest that further investigation of the individual-level effects of rape and torture, as well the historic, systemic, and collective effects, e.g., on families and societies, is required.

The neurobiology of emotion regulation in posttraumatic stress disorder: Amygdala downregulation via real-time fMRI neurofeedback

Amygdala dysregulation has been shown to be central to the pathophysiology of posttraumatic stress disorder (PTSD) representing a critical treatment target. Here, amygdala downregulation was targeted using real-time fMRI neurofeedback (rt-fMRI-nf) in patients with PTSD, allowing us to examine further the regulation of emotional states during symptom provocation. Patients (n = 10) completed three sessions of rt-fMRI-nf with the instruction to downregulate activation in the amygdala, while viewing personalized trauma words. Amygdala downregulation was assessed by contrasting (a) regulate trials, with (b) viewing trauma words and not attempting to regulate. Training was followed by one transfer run not involving neurofeedback. Generalized psychophysiological interaction (gPPI) and dynamic causal modeling (DCM) analyses were also computed to explore task-based functional connectivity and causal structure, respectively. It was found that PTSD patients were able to successfully downregulate both right and left amygdala activation, showing sustained effects within the transfer run. Increased activation in the dorsolateral and ventrolateral prefrontal cortex (PFC), regions related to emotion regulation, was observed during regulate as compared with view conditions. Importantly, activation in the PFC, rostral anterior cingulate cortex, and the insula, were negatively correlated to PTSD dissociative symptoms in the transfer run. Increased functional connectivity between the amygdala- and both the dorsolateral and dorsomedial PFC was found during regulate, as compared with view conditions during neurofeedback training. Finally, our DCM analysis exploring directional structure suggested that amygdala downregulation involves both top-down and bottom-up information flow with regard to observed PFC-amygdala connectivity. This is the first demonstration of successful downregulation of the amygdala using rt-fMRI-nf in PTSD, which was critically sustained in a subsequent transfer run without neurofeedback, and corresponded to increased connectivity with prefrontal regions involved in emotion regulation during the intervention. Hum Brain Mapp 38:541-560, 2017. © 2016 Wiley Periodicals, Inc.

Novel pharmacological treatment strategies for posttraumatic stress disorder

INTRODUCTION

A wide range of medications have been studied for posttraumatic stress disorder (PTSD) and a number are registered for this indication. Nevertheless, current pharmacotherapies are only partially effective in some patients, and are minimally effective in others. Thus novel treatment avenues need to be explored. Areas covered: In considering novel pharmacological agents for the treatment of PTSD, this paper takes a translational approach. We outline how advances in our understanding of the underlying neurobiology of PTSD may inform the identification of potential new treatment targets, including glutamatergic, noradrenergic and opioid pathways. Expert commentary: Continued investigation of the neural substrates and signalling pathways involved in responses to trauma may inform the development of novel treatment targets for future drug development for PTSD. However, the translation of preclinical findings to clinical practice is likely to be complex and gradual.

fMRI functional connectivity of the periaqueductal gray in PTSD and its dissociative subtype

BACKGROUND

Posttraumatic stress disorder (PTSD) is associated with hyperarousal and active fight or flight defensive responses. By contrast, the dissociative subtype of PTSD, characterized by depersonalization and derealization symptoms, is frequently accompanied by additional passive or submissive defensive responses associated with autonomic blunting. Here, the periaqueductal gray (PAG) plays a central role in defensive responses, where the dorsolateral (DL-PAG) and ventrolateral PAG (VL-PAG) are thought to mediate active and passive defensive responses, respectively.

METHODS

We examined PAG subregion (dorsolateral and ventrolateral) resting-state functional connectivity in three groups: PTSD patients without the dissociative subtype (n = 60); PTSD patients with the dissociative subtype (n = 37); and healthy controls (n = 40) using a seed-based approach via PickAtlas and SPM12.

RESULTS

All PTSD patients showed extensive DL- and VL-PAG functional connectivity at rest with areas associated with emotional reactivity and defensive action as compared to controls (n = 40). Although all PTSD patients demonstrated DL-PAG functional connectivity with areas associated with initiation of active coping strategies and hyperarousal (e.g., dorsal anterior cingulate; anterior insula), only dissociative PTSD patients exhibited greater VL-PAG functional connectivity with brain regions linked to passive coping strategies and increased levels of depersonalization (e.g., temporoparietal junction; rolandic operculum).

CONCLUSIONS

These findings suggest greater defensive posturing in PTSD patients even at rest and demonstrate that those with the dissociative subtype show unique patterns of PAG functional connectivity when compared to those without the subtype. Taken together, these findings represent an important first step toward identifying neural and behavioral targets for therapeutic interventions that address defensive strategies in trauma-related disorders.

Enhanced noradrenergic activity in the amygdala contributes to hyperarousal in an animal model of PTSD

Increased activity of the noradrenergic system in the amygdala has been suggested to contribute to the hyperarousal symptoms associated with post-traumatic stress disorder (PTSD). However, only two studies have examined the content of noradrenaline or its metabolites in the amygdala of rats previously exposed to traumatic stress showing inconsistent results. The aim of this study was to investigate the effects of an inescapable foot shock (IFS) procedure (1) on reactivity to novelty in an open-field (as an index of hyperarousal), and (2) on noradrenaline release in the amygdala during an acute stress. To test the role of noradrenaline in amygdala, we also investigated the effects of microinjections of propranolol, a β-adrenoreceptor antagonist, and clenbuterol, a β-adrenoreceptor agonist, into the amygdala of IFS and control animals. Finally, we evaluated the expression of mRNA levels of β-adrenoreceptors (β1 and β2) in the amygdala, the hippocampus and the prefrontal cortex. Male Wistar rats (3 months) were stereotaxically implanted with bilateral guide cannulae. After recovering from surgery, animals were exposed to IFS (10 shocks, 0.86mA, and 6s per shock) and seven days later either microdialysis or microinjections were performed in amygdala. Animals exposed to IFS showed a reduced locomotion compared to non-shocked animals during the first 5min in the open-field. In the amygdala, IFS animals showed an enhanced increase of noradrenaline induced by stress compared to control animals. Bilateral microinjections of propranolol (0.5μg) into the amygdala one hour before testing in the open-field normalized the decreased locomotion observed in IFS animals. On the other hand, bilateral microinjections of clenbuterol (30ng) into the amygdala of control animals did not change the exploratory activity induced by novelty in the open field. IFS modified the mRNA expression of β1 and β2 adrenoreceptors in the prefrontal cortex and the hippocampus. These results suggest that an increased noradrenergic activity in the amygdala contributes to the expression of hyperarousal in an animal model of PTSD.

New translational perspectives for blood-based biomarkers of PTSD: From glucocorticoid to immune mediators of stress susceptibility

Although biological systems have evolved to promote stress-resilience, there is variation in stress-responses. Understanding the biological basis of such individual differences has implications for understanding Posttraumatic Stress Disorder (PTSD) etiology, which is a maladaptive response to trauma occurring only in a subset of vulnerable individuals. PTSD involves failure to reinstate physiological homeostasis after traumatic events and is due to either intrinsic or trauma-related alterations in physiological systems across the body. Master homeostatic regulators that circulate and operate throughout the organism, such as stress hormones (e.g., glucocorticoids) and immune mediators (e.g., cytokines), are at the crossroads of peripheral and central susceptibility pathways and represent promising functional biomarkers of stress-response and target for novel therapeutics.

Alpha oscillation neurofeedback modulates amygdala complex connectivity and arousal in posttraumatic stress disorder

OBJECTIVE

Electroencephalogram (EEG) neurofeedback aimed at reducing the amplitude of the alpha-rhythm has been shown to alter neural networks associated with posttraumatic stress disorder (PTSD), leading to symptom alleviation. Critically, the amygdala is thought to be one of the central brain regions mediating PTSD symptoms. In the current study, we compare directly patterns of amygdala complex connectivity using fMRI, before and after EEG neurofeedback, in order to observe subcortical mechanisms associated with behavioural and alpha oscillatory changes among patients.

METHOD

We examined basolateral (BLA), centromedial (CMA), and superficial (SFA) amygdala complex resting-state functional connectivity using a seed-based approach via SPM Anatomy Toolbox. Amygdala complex connectivity was measured in twenty-one individuals with PTSD, before and after a 30-minute session of EEG neurofeedback targeting alpha desynchronization.

RESULTS

EEG neurofeedback was associated with a shift in amygdala complex connectivity from areas implicated in defensive, emotional, and fear processing/memory retrieval (left BLA and left SFA to the periaqueductal gray, and left SFA to the left hippocampus) to prefrontal areas implicated in emotion regulation/modulation (right CMA to the medial prefrontal cortex). This shift in amygdala complex connectivity was associated with reduced arousal, greater resting alpha synchronization, and was negatively correlated to PTSD symptom severity.

CONCLUSION

These findings have significant implications for developing targeted non-invasive treatment interventions for PTSD patients that utilize alpha oscillatory neurofeedback, showing evidence of neuronal reconfiguration between areas highly implicated in the disorder, in addition to acute symptom alleviation.

Influence of daily social stimulation on behavioral and physiological outcomes in an animal model of PTSD

INTRODUCTION

We have shown in previous work that acute episodes of predator exposure occurring in the context of chronic social instability produced PTSD-like sequelae in rats. Our animal model of PTSD contained two components: (1) acute trauma, immobilization of rats in close proximity to a cat twice in 10 days, and (2) chronic social instability, 31 days of randomized housing of cage cohorts. Here we tested the hypothesis that daily social stimulation would block the development of the PTSD-like sequelae.

METHODS

Beginning 24 h after the first cat exposure, adult male rats were given our established PTSD model, alone or in conjunction with daily social stimulation, in which all rats within a group interacted in a large apparatus for 2 h each day for the final 30 days of the PTSD regimen. All behavioral, for example, anxiety, memory, startle testing, and physiological assessments, for example, body growth, organ weights, and corticosterone levels, took place following completion of the psychosocial stress period.

RESULTS

Daily social stimulation blocked the expression of a subset of PTSD-like effects, including predator-based cued fear conditioning, enhanced startle response, heightened anxiety on the elevated plus maze and the stress-induced suppression of growth rate. We also found that social stimulation and psychosocial stress produced equivalent outcomes in some measures, including adrenal and heart hypertrophy, thymus atrophy, and a reduction in poststress corticosterone levels.

CONCLUSIONS

Daily exposure of rats to a highly social environment blocked the development of a subset of trauma-induced sequelae, particularly fear-related outcomes. It is notable that daily social stimulation normalized a subset, but not all, of the PTSD-like effects. We discuss our findings in the context of the literature demonstrating that social stimulation can counteract the adverse effects of traumatic stress on behavioral and physiological measures, as well as to produce its own stress-like outcomes.

Neuroanatomical features in soldiers with post-traumatic stress disorder

Background

Posttraumatic stress disorder (PTSD), an anxiety disorder that can develop after exposure to psychological trauma, impacts up to 20 % of soldiers returning from combat-related deployment. Advanced neuroimaging holds diagnostic and prognostic potential for furthering our understanding of its etiology. Previous imaging studies on combat-related PTSD have focused on selected structures, such as the hippocampi and cortex, but none conducted a comprehensive examination of both the cerebrum and cerebellum. The present study provides a complete analysis of cortical, subcortical, and cerebellar anatomy in a single cohort. Forty-seven magnetic resonance images (MRIs) were collected from 24 soldiers with PTSD and 23 Control soldiers. Each image was segmented into 78 cortical brain regions and 81,924 vertices using the corticometric iterative vertex based estimation of thickness algorithm, allowing for both a region-based and a vertex-based cortical analysis, respectively. Subcortical volumetric analyses of the hippocampi, cerebellum, thalamus, globus pallidus, caudate, putamen, and many sub-regions were conducted following their segmentation using Multiple Automatically Generated Templates Brain algorithm.

Results

Participants with PTSD were found to have reduced cortical thickness, primarily in the frontal and temporal lobes, with no preference for laterality. The region-based analyses further revealed localized thinning as well as thickening in several sub-regions. These results were accompanied by decreased volumes of the caudate and right hippocampus, as computed relative to total cerebral volume. Enlargement in several cerebellar lobules (relative to total cerebellar volume) was also observed in the PTSD group.

Conclusions

These data highlight the distributed structural differences between soldiers with and without PTSD, and emphasize the diagnostic potential of high-resolution MRI.

What I have changed my mind about and why

This paper is based upon a panel discussion "What I Have Changed My Mind About and Why" held on 5 November in New Orleans, Louisiana (USA), as part of the ISTSS 2015 annual meeting "Back to Basics: Integrating Clinical and Scientific Knowledge to Advance the Field of Trauma." The panel was chaired by Professor Dr. Rachel Yehuda of the Icahn School of Medicine at Mount Sinai and the James J. Peters Veterans Affairs, and included five clinician-scholars who exchanged thoughts about what they have changed their minds about over the years: Dr. David Spiegel, Dr. Steven Southwick, Dr. Lori Davis, Dr. Thomas Neylan, and Dr. John Krystal. This paper provides a summary of the salient points made by each expert and the questions and discussion that ensured. Major issues raised included the increasingly clear limitations to the fear-based model that has advanced the field. While treatments for PTSD have improved, there are some aspects of trauma exposure that cannot be entirely repaired. Research providing an evidence base to treatment has led to overly specific treatment guidelines that may obscure more general principles of effective treatment. Treatment might be viewed as a way to increase the plasticity of the brain in the context of processing social cues. A variety of novel and integrative therapies include comprehensive holistic care, exercise, returning to competitive work, logotherapy, mindfulness, enhancing well-being and resilience, and medications with novel mechanisms, such as ketamine.