A review of neuroimaging studies in PTSD: heterogeneity of response to symptom provocation

Neural correlates of stress-reactive rumination in depression - The role of childhood trauma and social anxiety

Recent work showed an association of prefrontal dysfunctions in patients with Major Depressive Disorder (MDD) and social stress induced rumination. However, up to date it is unclear which etiological features of MDD might cause prefrontal dysfunctions. In the study at hand, we aimed to replicate recent findings, that showed prefrontal activation alterations during the Trier Social Stress Test (TSST) and subsequently increased stress-reactive rumination in MDD compared to healthy controls. Moreover, we aimed to explore the role of adverse childhood experiences and other clinical variables in this relationship. N = 55 patients currently suffering from MDD and n = 42 healthy controls (HC) underwent the TSST, while cortical activity in areas of the Cognitive Control Network (CCN) was measured via functional near-infrared spectroscopy (fNIRS). The TSST successfully induced a stress reaction (physiologically, as well as indicated by subjective stress ratings) and state rumination in all subjects with moderate to large effect sizes. In comparison to HC, MDD patients showed elevated levels of state rumination with large effect sizes, as well as a typical pattern of reduced cortical oxygenation during stress in the CCN with moderate effect sizes. Self-reported emotional abuse and social anxiety were moderately positively associated with increased stress-reactive rumination. Within the MDD sample, emotional abuse was negatively and social anxiety positively associated with cortical oxygenation within the CCN with moderate to large effect sizes. In conclusion, our results replicate previous findings on MDD-associated prefrontal hypoactivity during stress and extends the research toward specific subtypes of depression.

A neural oscillatory signature of sustained anxiety

BACKGROUND

Anxiety is a sustained response to uncertain threats; yet few studies have explored sustained neurobiological activities underlying anxious states, particularly spontaneous neural oscillations. To address this gap, we reanalysed magnetoencephalographic (MEG) data recorded during induced anxiety to identify differences in sustained oscillatory activity between high- and low-anxiety states.

METHODS

We combined data from three previous MEG studies in which healthy adults (total N = 51) were exposed to alternating periods of threat of unpredictable shock and safety while performing a range of cognitive tasks (passive oddball, mixed-saccade or stop-signal tasks). Spontaneous, band-limited, oscillatory activity was extracted from middle and late intervals of the threat and safe periods, and regional power distributions were reconstructed with adaptive beamforming. Conjunction analyses were used to identify regions showing overlapping spectral power differences between threat and safe periods across the three task paradigms.

RESULTS

MEG source analyses revealed a robust and widespread reduction in beta (14-30 Hz) power during threat periods in bilateral sensorimotor cortices extending into right prefrontal regions. Alpha (8-13 Hz) power reductions during threat were more circumscribed, with notable peaks in left intraparietal sulcus and thalamus.

CONCLUSIONS

Threat-induced anxiety is underpinned by a sustained reduction in spontaneous beta- and alpha-band activity in sensorimotor and parietal cortical regions. This general oscillatory pattern likely reflects a state of heightened action readiness and vigilance to cope with uncertain threats. Our findings provide a critical reference for which to identify abnormalities in cortical oscillatory activities in clinically anxious patients as well as evaluating the efficacy of anxiolytic treatments.

The Challenge of Fibromyalgia Efficacy of Hypnosis in Alleviating the Invisible Pain: A Narrative Review

Fibromyalgia syndrome (FMS) is a multifaceted and incapacitating functional pain syndrome characterized by continuous, severe, widespread musculoskeletal pain. FMS is associated with other symptoms such as fatigue, nonrestorative sleep, cognitive/emotional dysfunction, and diminished health-related quality of life. The pathogenesis of FMS is still not fully understood, but an increasing amount of evidence supports the link between childhood/adulthood emotional, physical, sexual abuse or neglect and the development of FMS. Managing and treating FMS patients can be challenging because the syndrome is refractory to most treatments. However, psychological interventions, particularly hypnotherapy, have been shown to be effective in the cognitive modulation of fibromyalgic pain. FMS patients may benefit from hypnotherapy alone or in combination with standard medical therapy. Symptom-oriented hypnosis aims to reduce pain, fatigue, sleep problems, anxiety, and depression, while hypnotherapy focuses on resolving emotional conflicts and unresolved traumas associated with FMS. In conclusion, hypnosis may be a useful and safe adjunct tool for managing chronic pain and dysfunctional symptoms in challenging fibromyalgic patients.

Post-traumatic stress disorder (PTSD), cognitive control, and perceived seizure control in patients with epilepsy: An exploratory study

Epilepsy is often linked to various psychiatric symptoms, with anxiety, depression, and interictal dysphoric disorders being the most prevalent. Few studies have investigated posttraumatic stress disorder (PTSD) in epilepsy, but they suggest a notable prevalence of PTSD. PTSD is known to be associated with cognitive impairments, particularly memory and executive functions. Our proposed exploratory study aims to investigate executive attentional control and emotional inhibition in patients with drug-resistant epilepsy (DRE) who exhibit PTSD symptoms compared with a healthy control group. Additionally, some PWE can manage their seizures using emotional and cognitive strategies, we find it relevant to explore the connection between their regulation abilities, cognitive control performance, and PTSD symptoms. We included 54 PWE and 60 healthy participants. They completed anxiety and depression scales as well as two questionnaires assessing PTSD symptoms and a questionnaire that measured the perceived self-control of seizures. We measured executive control using an executive control task (Attention Network Test, ANT) and an emotional Go/No-Go task. We found a positive correlation between PTSD scores (PDS-5) and performance at the ANT task. In contrast, in the emotional inhibition (Go/No-Go) task, behavioral inhibition errors were positively correlated with PTSD scores, specifically with hypervigilance symptoms in PTSD+ patients. There was a positive correlation between response reaction times in an aversive condition and PTSD scores: the more severe the PTSD symptoms, the faster the PWE identified stimuli in the angry face condition of the Go/No-Go task. Regarding perceived seizure control, we found correlations between alertness and PTSD symptoms associated with seizure anticipation during the inter- and peri-ictal periods. Patients with PTSD symptoms reported better seizure control. Our findings suggest that epilepsy patients with PTSD experience cognitive changes such as heightened executive attentional control, weakened emotional inhibition, and improved seizure control perception.

Musical experience prior to traumatic exposure as a resilience factor: a conceptual analysis

Resilience mechanisms can be dynamically triggered throughout the lifecourse by resilience factors in order to prevent individuals from developing stress-related pathologies such as posttraumatic stress disorder (PTSD). Some interventional studies have suggested that listening to music and musical practice after experiencing a traumatic event decrease the intensity of PTSD, but surprisingly, no study to our knowledge has explored musical experience as a potential resilience factor before the potential occurrence of a traumatic event. In the present conceptual analysis, we sought to summarize what is known about the concept of resilience and how musical experience could trigger two key mechanisms altered in PTSD: emotion regulation and cognitive control. Our hypothesis is that the stimulation of these two mechanisms by musical experience during the pre-traumatic period could help protect against the symptoms of emotional dysregulation and intrusions present in PTSD. We then developed a new framework to guide future research aimed at isolating and investigating the protective role of musical experience regarding the development of PTSD in response to trauma. The clinical application of this type of research could be to develop pre-trauma training that promotes emotional regulation and cognitive control, aimed at populations at risk of developing PTSD such as healthcare workers, police officers, and military staffs.

The Lingering Impact of Resolved PTSD on Subsequent Functioning

This study investigated whether impairment persists after posttraumatic stress disorder (PTSD) has resolved. Traumatically injured patients (N = 1,035) were assessed during hospital admission and at 3 (85%) and 12 months (73%). Quality of life prior to traumatic injury was measured with the World Health Organization Quality of Life-BREF during hospitalization and at each subsequent assessment. PTSD was assessed using the Clinician-Administered PTSD Scale at 3 and 12 months. After controlling for preinjury functioning, current pain, and comorbid depression, patients whose PTSD symptoms had resolved by 12 months were more likely to have poorer quality of life in psychological (OR = 3.51), physical (OR = 10.17), social (OR = 4.54), and environmental (OR = 8.83) domains than those who never developed PTSD. These data provide initial evidence that PTSD can result in lingering effects on functional capacity even after remission of symptoms. Reprinted from Clin Psychol Sci 2016; 4:493-498, with permission from Sage. Copyright © 2016.

Functional correlates of subliminal stimulation in Posttraumatic Stress Disorder: Systematic review and meta-analysis

Patients with Post-traumatic stress disorder (PTSD) exposed to traumatic reminders show hyperreactivity in brain areas (e.g., amygdala) belonging or related to the Innate Alarm System (IAS), allowing the rapid processing of salient stimuli. Evidence that IAS is activated by subliminal trauma-reminders could shed a new light on the factors precipitating and perpetuating PTSD symptomatology. Thus, we systematically reviewed studies investigating neuroimaging correlates of subliminal stimulation in PTSD. Twenty-three studies were selected from the MEDLINE and Scopus® databases for a qualitative synthesis, 5 of which allowed a further meta-analysis of fMRI data. The intensity of IAS responses to subliminal trauma-related reminders ranged from a minimum in healthy controls to a maximum in the PTSD patients with the most severe (e.g., dissociative) symptoms or the least responsiveness to treatment. Comparisons with other disorders (e.g., phobias) revealed contrasting results. Our findings demonstrate the hyperactivation of areas belonging or related to IAS in response to unconscious threats that should be integrated in diagnostic as well as in therapeutic protocols.

The underlying mechanisms by which PTSD symptoms are associated with cardiovascular health in male UK military personnel: The ADVANCE cohort study

Post-Traumatic Stress Disorder (PTSD) has been identified as an independent risk factor for cardiovascular disease, but the mechanisms of this relationship are not well understood. This study investigates the associations between PTSD symptom clusters (hyperarousal, intrusive thoughts, avoidance behaviours and emotional numbing) and mechanisms of cardiovascular disease including cardiometabolic effects, inflammation, and haemodynamic functioning. In the ADVANCE study cohort of UK male military personnel, 1111 participants were assessed for PTSD via questionnaire and cardiovascular risk via venous blood sampling, pulse wave analysis and dual energy x-ray absorptiometry between 2015 and 2020. Variable selection procedures were conducted to assess which of the symptom clusters if any were associated with cardiovascular risk outcomes. Associations were confirmed via robust regression modelling. Avoidance behaviours were associated with greater systolic Blood Pressure (BP) (Adjusted Coefficient (AC) 0.640 (95% Confidence Interval (CI) 0.065, 1.149). Emotional numbing was associated with greater estimated glucose disposal rate (AC -0.021 (95%CI -0.036, -0.005). Hyperarousal was associated with greater levels of (log)triglycerides (exponentiated-AC 1.009 (95%CI 1.002, 1.017). Intrusive thoughts were associated with greater visceral adipose tissue (AC 0.574 (95%CI 0.020, 1.250). Nonlinear relationships were observed between emotional numbing with heart rate and intrusive thoughts with systolic BP. Limited evidence is present for symptom associations with lipoproteins and pulse wave velocity. No associations were observed between PTSD symptom clusters and high sensitivity c-reactive protein, diastolic BP, total cholesterol, or haemoglobin fasting glucose. In conclusion, symptom clusters of PTSD were associated with increased cardiovascular risk via cardiometabolic and haemodynamic functioning mechanisms, but not inflammation.

Altered brain activity and functional connectivity after MDMA-assisted therapy for post-traumatic stress disorder

Introduction

3,4-methylenedioxymethamphetamine-assisted therapy (MDMA-AT) for post-traumatic stress disorder (PTSD) has demonstrated promise in multiple clinical trials. MDMA is hypothesized to facilitate the therapeutic process, in part, by decreasing fear response during fear memory processing while increasing extinction learning. The acute administration of MDMA in healthy controls modifies recruitment of brain regions involved in the hyperactive fear response in PTSD such as the amygdala, hippocampus, and insula. However, to date there have been no neuroimaging studies aimed at directly elucidating the neural impact of MDMA-AT in PTSD patients.

Methods

We analyzed brain activity and connectivity via functional MRI during both rest and autobiographical memory (trauma and neutral) response before and two-months after MDMA-AT in nine veterans and first-responders with chronic PTSD of 6 months or more.

Results

We hypothesized that MDMA-AT would increase amygdala-hippocampus resting-state functional connectivity, however we only found evidence of a trend in the left amygdala-left hippocampus (t = -2.91, uncorrected p = 0.0225, corrected p = 0.0901). We also found reduced activation contrast (trauma > neutral) after MDMA-AT in the cuneus. Finally, the amount of recovery from PTSD after MDMA-AT correlated with changes in four functional connections during autobiographical memory recall: the left amygdala-left posterior cingulate cortex (PCC), left amygdala-right PCC, left amygdala-left insula, and left isthmus cingulate-left posterior hippocampus.

Discussion

Amygdala-insular functional connectivity is reliably implicated in PTSD and anxiety, and both regions are impacted by MDMA administration. These findings compliment previous research indicating that amygdala, hippocampus, and insula functional connectivity is a potential target of MDMA-AT, and highlights other regions of interest related to memory processes. More research is necessary to determine if these findings are specific to MDMA-AT compared to other types of treatment for PTSD.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT02102802, identifier NCT02102802.

Increased top-down control of emotions during symptom provocation working memory tasks following a RCT of alpha-down neurofeedback in PTSD

BACKGROUND

Posttraumatic stress disorder (PTSD) has been found to be associated with emotion under-modulation from the prefrontal cortex and a breakdown of the top-down control of cognition and emotion. Novel adjunct therapies such as neurofeedback (NFB) have been shown to normalize aberrant neural circuits that underlie PTSD psychopathology at rest. However, little evidence exists for NFB-linked neural improvements under emotionally relevant cognitive load. The current study sought to address this gap by examining the effects of alpha-down NFB in the context of an emotional n-back task.

METHODS

We conducted a 20-week double-blind randomized, sham-controlled trial of alpha-down NFB and collected neuroimaging data before and after the NFB protocol. Participants performed an emotional 1-back and 2-back working memory task, with interleaved trauma-neutral and trauma-relevant cues in the fMRI scanner. Data from 35 participants with a primary diagnosis of PTSD were analyzed in this study (n = 18 in the experimental group undergoing alpha-down NFB, n = 17 in the sham-control group).

RESULTS

Firstly, within-group analyses showed clinically significant reductions in PTSD symptom severity scores at the post-intervention timepoint and 3-month follow-up for the experimental group, and not for the sham-control group. The neuroimaging analyses revealed that alpha-down NFB enhanced engagement of top-down cognitive and emotional control centers, such as the dorsolateral prefrontal cortex (dlPFC), and improved integration of the anterior and posterior parts of the default mode network (DMN). Finally, our results also indicate that increased alpha-down NFB performance correlated with increased activity in brain regions involved in top-down control and bodily consciousness/embodied processing of self (TPJ and posterior insula).

CONCLUSION

This is the first study to provide mechanistic insights into how NFB may normalize dysfunctional brain activity and connectivity in PTSD under cognitive load with simultaneous symptom provocation, adding to a growing body of evidence supporting the therapeutic neuromodulatory effects of NFB. This preliminary study highlights the benefits of alpha-down NFB training as an adjunctive therapy for PTSD and warrants further investigation into its therapeutic effects on cognitive and emotion control in those with PTSD.

Hyperexcitability: From Normal Fear to Pathological Anxiety and Trauma

Hyperexcitability in fear circuits is suggested to be important for development of pathological anxiety and trauma from adaptive mechanisms of fear. Hyperexcitability is proposed to be due to acquired sensitization in fear circuits that progressively becomes more severe over time causing changing symptoms in early and late pathology. We use the metaphor and mechanisms of kindling to examine gains and losses in function of one excitatory and one inhibitory neuropeptide, corticotrophin releasing factor and somatostatin, respectively, to explore this sensitization hypothesis. We suggest amygdala kindling induced hyperexcitability, hyper-inhibition and loss of inhibition provide clues to mechanisms for hyperexcitability and progressive changes in function initiated by stress and trauma.

Reexperiencing and anxious arousal symptoms in relation to volumes of thalamus nuclei in posttraumatic stress spectrum adults

INTRODUCTION

Trauma reexperiencing is dominated by recollection of sensory-perceptual elements of the trauma, pointing to involvement of the sensory thalamus. This study examined posttraumatic stress symptoms in relation to volumes of thalamic nuclei that were grouped based on their predominant functions. We hypothesized that reexperiencing, controlling for other symptom dimensions, would correlate with volumes of thalamic nuclei involved in primary and higher-order sensory processing.

METHODS

Seventy-two trauma-exposed adults were interviewed with the Clinician Administered PTSD Scale for DSM-IV and underwent 3T magnetic resonance imaging. Scores were derived for reexperiencing, anxious arousal, dysphoric arousal, emotional numbing, and avoidance symptoms. These were entered as simultaneous predictors in five separate regression analyses, with age, sex, and total thalamus volume as covariates, predicting volumesf of five thalamus nuclear groupings corrected for intracranial volume: Specific sensory, associative-sensory, associative-cognitive, intralaminar, and motor groupings.

RESULTS

Reexperiencing symptoms were significantly positively correlated with volumes of the motor thalamic grouping, which included the ventral anterior, ventral lateral, and ventromedial nuclei. Anxious arousal was significantly negatively correlated with volumes of all five thalamic groupings.

CONCLUSIONS

Reexperiencing symptoms were correlated with volumes of the motor thalamus, while anxious arousal symptoms were related to all thalamic subregion volumes. Thalamic nuclei involved in motor functions, including oculomotor control and motor planning, may be implicated in posttraumatic reexperiencing symptoms.

Brain Responses to a Self-Compassion Induction in Trauma Survivors With and Without Post-traumatic Stress Disorder

Self-compassion (SC) is a mechanism of symptom improvement in post-traumatic stress disorder (PTSD), however, the underlying neurobiological processes are not well understood. High levels of self-compassion are associated with reduced activation of the threat response system. Physiological threat responses to trauma reminders and increased arousal are key symptoms which are maintained by negative appraisals of the self and self-blame. Moreover, PTSD has been consistently associated with functional changes implicated in the brain's saliency and the default mode networks. In this paper, we explore how trauma exposed individuals respond to a validated self-compassion exercise. We distinguish three groups using the PTSD checklist; those with full PTSD, those without PTSD, and those with subsyndromal PTSD. Subsyndromal PTSD is a clinically relevant subgroup in which individuals meet the criteria for reexperiencing along with one of either avoidance or hyperarousal. We use electroencephalography (EEG) alpha-asymmetry and EEG microstate analysis to characterize brain activity time series during the self-compassion exercise in the three groups. We contextualize our results with concurrently recorded autonomic measures of physiological arousal (heart rate and skin conductance), parasympathetic activation (heart rate variability) and self-reported changes in state mood and self-perception. We find that in all three groups directing self-compassion toward oneself activates the negative self and elicits a threat response during the SC exercise and that individuals with subsyndromal PTSD who have high levels of hyperarousal have the highest threat response. We find impaired activation of the EEG microstate associated with the saliency, attention and self-referential processing brain networks, distinguishes the three PTSD groups. Our findings provide evidence for potential neural biomarkers for quantitatively differentiating PTSD subgroups.

A Systematic Approach to Neuropsychiatric Intervention: Functional Neuroanatomy Underlying Symptom Domains as Targets for Treatment

An ever-growing population experiences a wide range of psychopathologies, and there is now more than ever a need for clear differential diagnoses between disorders. Furthering this need is the fact that many psychological, psychiatric, and neurological disorders have overlapping features. Functional neuroimaging has been shown to differentiate not only between the function of different brain structures but also between the roles of these structures in functional networks. The aim of this article is to aid in the goal of parsing out disorders on the basis of specific symptom domains by utilizing the most recent literature on functional networks. Current literature on the role of brain networks in relation to different psychopathological symptom domains is examined and corresponding circuit-based therapies that have been or may be used to treat them are discussed. Research on depression, obsession and compulsions, addiction, anxiety, and psychosis is reviewed. An understanding of networks and their specific dysfunctions opens the possibility of a new form of psychopathological treatment.

Skin conductance response to trauma interview as a candidate biomarker of trauma and related psychopathology in youth resettled as refugees

Background: Posttraumatic stress symptoms (PTSS) include a constellation of physical and emotional profiles that youth exposed to trauma may experience. An estimated 20% of youth are exposed to trauma, and in refugee populations, up to 54% experience posttraumatic stress. Given the physical and mental health consequences associated with trauma exposure and subsequent psychopathology, identifying biomarkers of symptom severity is a top research priority. Objective: Previous research in adults found that skin conductance responses to trauma interview predicted current and future PTSS. We extended this method to refugee youth exposed to civilian war trauma and forced migration, to examine associations between PTSS and skin conductance in this uniquely vulnerable child and adolescent population. Methods: 86 refugee youth ages 7-17 years completed a trauma interview and assessment of self-reported PTSS. The mobile eSense app on a iPad was used to obtain continuous recordings of skin conductance level (SCL) during a trauma interview (trauma SCL). Skin conductance response (SCR) was calculated by subtracting the baseline SCL from the maximum amplitude of the trauma SCL. Results: SCL during trauma was significantly greater than baseline SCL, Trauma exposure was significantly associated with SCR to trauma interview, R²= .084, p = .042. SCR to trauma interview was positively correlated with reexperiencing (R² = .127, p = .028), and hyperarousal symptoms (R ²= .123, p = .048). Conclusions: The present study provides evidence for feasibility of SCR to trauma interview as a candidate biomarker of PTSS in youth. This is the first study to look at SCR to trauma interview in youth resettled as refugees and is part of the limited but growing body of research to look at biomarkers in refugee cohorts more broadly. As the number of forcibly displaced persons surges, early detection and prevention of trauma-related psychology is becoming more important than ever.

HIGHLIGHTS

Using the mobile eSense app, we demonstrate that skin conductance is measurable in a variety of research settings and that skin conductance response may be a biological indicator of trauma and related psychopathology - namely re-experiencing symptoms - in youth resettled as refugees.

Neural Underpinnings of Social Stress in Substance Use Disorders

BACKGROUND

Drug addiction is a complex brain disorder that is characterized by craving, withdrawal, and relapse, which can be perpetuated by social stress. Stemming from an acute life event, chronic stress, or trauma in a social context, social stress has a major role in the initiation and trajectory of substance use. Preclinical literature shows that early life stress exposure and social isolation facilitate and enhance drug self-administration. Epidemiological evidence links childhood adversity to increased risk for drug use and demonstrates that cumulative stress experiences are predictive of substance use severity in a dose-dependent manner. Stress and drug use induce overlapping brain alterations leading to downregulation or deficits in brain reward circuitry, thereby resulting in greater sensitization to the rewarding properties of drugs. Though stress in the context of addiction has been studied at the neural level, a gap in our understanding of the neural underpinnings of social stress in humans remains.

METHODS

We conducted a systematic review of in vivo structural and functional neuroimaging studies to evaluate the neural processes associated with social stress in individuals with substance use disorder. Results were considered in relation to participants' history of social stress and with regard to the effects of social stress induced during the neuroimaging paradigm.

RESULTS

An exhaustive search yielded 21 studies that matched inclusion criteria. Social stress induces broad structural and functional neural effects in individuals with substance use disorder throughout their lifespan and across drug classes. A few patterns emerged across studies: (1) many of the brain regions altered in individuals who were exposed to chronic social stress and during acute stress induction have been implicated in addiction networks (including the prefrontal cortex, insula, hippocampus, and amygdala); (2) individuals with childhood maltreatment and substance use history had decreased gray matter or activation in regions of executive functioning (including the medial prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex), the hippocampal complex, and the supplementary motor area; and (3) during stress-induction paradigms, activation in the anterior cingulate cortex, caudate, and amygdala was most commonly observed.

CONCLUSIONS/IMPLICATIONS

A distinct overlap is shown between social stress-related circuitry and addiction circuitry, particularly in brain regions implicated in drug-seeking, craving, and relapse. Given the few studies that have thoroughly investigated social stress, the evidence accumulated to date needs to be replicated and extended, particularly using research designs and methods that disentangle the effects of substance use from social stress. Future clinical studies can leverage this information to evaluate the impact of exposure to trauma or adverse life events within substance use research. Expanding knowledge in this emerging field could help clarify neural mechanisms underlying addiction risk and progression to guide causal-experimental inquiry and novel prevention and treatment strategies.

Trauma-related dissociation and the autonomic nervous system: a systematic literature review of psychophysiological correlates of dissociative experiencing in PTSD patients

Background: Neurophysiological models link dissociation (e.g. feeling detached during or after a traumatic event) to hypoarousal. It is currently assumed that the initial passive reaction to a threat may coincide with a blunted autonomic response, which constitutes the dissociative subtype of post-traumatic stress disorder (PTSD). Objective: Within this systematic review we summarize research which evaluates autonomic nervous system activation (e.g. heart rate, blood pressure) and dissociation in PTSD patients to discern the validity of current neurophysiological models of trauma-related hypoarousal. Method: Of 553 screened articles, 28 studies (N = 1300 subjects) investigating the physiological response to stress provocation or trauma-related interventions were included in the final analysis. Results: No clear trend exists across all measured physiological markers in trauma-related dissociation. Extracted results are inconsistent, in part due to high heterogeneity in experimental methodology. Conclusion: The current review is unable to provide robust evidence that peri- and post-traumatic dissociation are associated with hypoarousal, questioning the validity of distinct psychophysiological profiles in PTSD.

Impact of stress resilience and susceptibility on fear learning, anxiety, and alcohol intake

Post-traumatic stress disorder (PTSD) can develop after exposure to traumatic events and severely impacts the quality of life. PTSD is frequently comorbid with substance use disorders, with alcoholism being particularly common. However, not everyone who experiences trauma develops PTSD and the factors that render individuals susceptible or resilient to the effects of stress are unknown although gender appears to play an important role. Rodent models of stress exposure such as stress-enhanced fear learning (SEFL) recapitulate some aspects of PTSD symptomology, making them an invaluable tool for studying this disorder. This study examined whether exposure to a modified version of the SEFL procedure (4 footshocks instead of the standard 15 over 90 min) would reveal both susceptible and resilient subjects. Following stress exposure, distinct susceptible and resilient groups emerged that differed in fear learning and anxiety-related behavior as well as voluntary alcohol intake. Some aspects of stress susceptibility manifested differently in males compared to females, with susceptibility associated with increased alcohol intake in males and increased baseline anxiety in females.

Neural response to trauma-related and trauma-unrelated negative stimuli in remitted and persistent pediatric post-traumatic stress disorder

INTRODUCTION

Most youths who suffer from post-traumatic stress disorder (PTSD) lose their diagnosis in the first 1-2 years. However, there are few studies on this brain mechanism, and the heterogeneity of the findings is partially due to the different stimuli applied and the mixed trauma history. Therefore, the use of trauma-related/unrelated stimuli to study the remittance mechanism of earthquake-induced PTSD could advance our knowledge of PTSD and inspire future treatment.

METHODS

Thirteen youths with PTSD, 18 remitted participants, and 18 control participants underwent functional magnetic resonance imaging (fMRI), while viewing trauma-related pictures, trauma-unrelated negative pictures, and scrambled pictures.

RESULTS

Under trauma-unrelated condition, the neural activity of the left hippocampus in the remitted group was between the two other groups. Under trauma-related condition, the PTSD and the remitted group exhibited higher neural activity in the right middle occipital gyrus than controls. The remitted group showed higher neural activity in the right parahippocampal gyrus and right lingual gyrus under trauma-related condition than trauma-unrelated condition, while no significant difference was found in PTSD group.

CONCLUSION

PTSD status-related group differences are mainly reflected in the left hippocampus under the trauma-unrelated condition, while the hyperactivity in the right middle occipital gyrus under trauma-related condition could be an endophenotype for PTSD.

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

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

How Processing of Sensory Information From the Internal and External Worlds Shape the Perception and Engagement With the World in the Aftermath of Trauma: Implications for PTSD

Post-traumatic stress disorder (PTSD) is triggered by an individual experiencing or witnessing a traumatic event, often precipitating persistent flashbacks and severe anxiety that are associated with a fearful and hypervigilant presentation. Approximately 14–30% of traumatized individuals present with the dissociative subtype of PTSD, which is often associated with repeated or childhood trauma. This presentation includes symptoms of depersonalization and derealization, where individuals may feel as if the world or self is “dream-like” and not real and/or describe “out-of-body” experiences. Here, we review putative neural alterations that may underlie how sensations are experienced among traumatized individuals with PTSD and its dissociative subtype, including those from the outside world (e.g., touch, auditory, and visual sensations) and the internal world of the body (e.g., visceral sensations, physical sensations associated with feeling states). We postulate that alterations in the neural pathways important for the processing of sensations originating in the outer and inner worlds may have cascading effects on the performance of higher-order cognitive functions, including emotion regulation, social cognition, and goal-oriented action, thereby shaping the perception of and engagement with the world. Finally, we introduce a theoretical neurobiological framework to account for altered sensory processing among traumatized individuals with and without the dissociative subtype of PTSD.

Identification of psychiatric disorder subtypes from functional connectivity patterns in resting-state electroencephalography

The understanding and treatment of psychiatric disorders, which are known to be neurobiologically and clinically heterogeneous, could benefit from the data-driven identification of disease subtypes. Here, we report the identification of two clinically relevant subtypes of post-traumatic stress disorder (PTSD) and major depressive disorder (MDD) on the basis of robust and distinct functional connectivity patterns, prominently within the frontoparietal control network and the default mode network. We identified the disease subtypes by analysing, via unsupervised and supervised machine learning, the power-envelope-based connectivity of signals reconstructed from high-density resting-state electroencephalography in four datasets of patients with PTSD and MDD, and show that the subtypes are transferable across independent datasets recorded under different conditions. The subtype whose functional connectivity differed most from those of healthy controls was less responsive to psychotherapy treatment for PTSD and failed to respond to an antidepressant medication for MDD. By contrast, both subtypes responded equally well to two different forms of repetitive transcranial magnetic stimulation therapy for MDD. Our data-driven approach may constitute a generalizable solution for connectome-based diagnosis.

Distinct patterns of resting-state connectivity in U.S. service members with mild traumatic brain injury versus posttraumatic stress disorder

Mild traumatic brain injury (mTBI) is highly prevalent in military populations, with many service members suffering from long-term symptoms. Posttraumatic stress disorder (PTSD) often co-occurs with mTBI and predicts worse clinical outcomes. Functional neuroimaging research suggests there are both overlapping and distinct patterns of resting-state functional connectivity (rsFC) in mTBI versus PTSD. However, few studies have directly compared rsFC of cortical networks in military service members with these two conditions. In the present study, U.S. service members (n = 137; ages 19-59; 120 male) underwent resting-state fMRI scans. Participants were divided into three study groups: mTBI only, PTSD only, and orthopedically injured (OI) controls. Analyses investigated group differences in rsFC for cortical networks: default mode (DMN), frontoparietal (FPN), salience, somatosensory, motor, auditory, and visual. Analyses were family-wise error (FWE) cluster-corrected and Bonferroni-corrected for number of network seeds regions at the whole brain level (p_FWE < 0.002). Both mTBI and PTSD groups had reduced rsFC for DMN and FPN regions compared with OI controls. These group differences were largely driven by diminished connectivity in the PTSD group. rsFC with the middle frontal gyrus of the FPN was increased in mTBI, but decreased in PTSD. Overall, these results suggest that PTSD symptoms may have a more consistent signal than mTBI. Our novel findings of opposite patterns of connectivity with lateral prefrontal cortex highlight a potential biomarker that could be used to differentiate between these conditions.

The imprint of childhood adversity on emotional processing in high functioning young adults

Adverse childhood experiences (ACEs) have been acknowledged as risk factors for increased mental health complications in adulthood, specifically increasing susceptibility to developing psychopathology upon exposure to trauma. Yet, little is known regarding the impact of mild ACEs on highly functioning population. In this study forty participants were selected from a group of 366 highly selected military parachute trainees using the self-report "childhood trauma questionnaire," and classified into two groups of 20 each, with and without ACEs. Behavioral measurements were obtained before and at the peak of an intensive combat training period, including anxiety, depression and executive function assessment. Functional MRI including a negative emotional face perception task was conducted at the first time point. Psychometric and cognitive measurements revealed higher levels of anxiety and depressive symptoms, and more difficulties in executive functioning in the ACE group at baseline. Slower reaction time to emotional faces presentation was found in the ACE group. Lower activation in response to negative emotional faces stimuli was found in this group in bilateral secondary visual areas, left anterior insula, left parietal cortex and left primary motor and sensory regions. In contrast, higher activation in the ACE group was found in the right ventral lateral prefrontal cortex (Vlpfc). No significant differences between groups were detected in the amygdala. To conclude, mild adverse childhood experiences produce long-term sequela on psychological wellbeing and neurocircuitry even in high functioning population. Brain regions modulated by childhood trauma may instigate avoidance mechanisms dampening the emotional and cognitive effects of intensive stress.

Pain perception and processing in individuals with posttraumatic stress disorder: a systematic review with meta-analysis

Supplemental Digital Content is Available in the Text.

Posttraumatic stress disorder encompasses latent subgroups of individuals with qualitative differences in pain perception.

Posttraumatic stress disorder (PTSD) is a known risk factor for the development of chronic pain conditions, and almost 1 in 5 individuals with chronic pain fulfills the criteria for PTSD. However, the relationship between PTSD and pain is poorly understood and studies on pain perception in patients with PTSD show inconsistent results suggesting that different sensory profiles exist among individuals with PTSD. Here, we (1) systematically summarize the current literature on experimentally evoked pain perception in patients with PTSD compared to subjects without PTSD, and (2) assess whether the nature of the traumatic event is associated with different patterns in pain perception. The main outcome measures were pain threshold, pain tolerance, and pain intensity ratings as well as measures of temporal summation of pain and conditioned pain modulation. A systematic search of MEDLINE, EMBASE, Web of Science, PsycINFO, and CINAHL identified 21 studies for the meta-analysis, including 422 individuals with PTSD and 496 PTSD-free controls. No main effect of PTSD on any outcome measure was found. However, stratification according to the nature of trauma revealed significant differences of small to medium effect sizes. Combat-related PTSD was associated with increased pain thresholds, whereas accident-related PTSD was associated with decreased pain thresholds. No clear relationship between PTSD and experimentally evoked pain perception exists. The type of trauma may affect pain thresholds differently indicating the presence of different subgroups with qualitative differences in pain processing.

Dissociative Symptoms In Posttraumatic Stress Disorder: A Systematic Review

Objectives: Research on dissociative symptomatology in the context of Posttraumatic Stress Disorder (PTSD) has been gaining traction, with dissociation being studied as a set of complex symptoms following trauma exposure and as a specific subtype of PTSD. The aims of this review are to summarize the literature as it stands, examine the efficacy of existing interventions in treating dissociative symptomatology within the context of PTSD, and offer potential suggestions for future research. Methods: A systematic approach was taken to locate empirical studies on PTSD that included dissociation as an outcome in the PubMed, Scopus, and PsycINFO databases. Recent experimental designs with adult subjects (18+ years) in the English language were included, yielding 103 potentially eligible studies. Thirty-three full-text articles were screened with 17 articles meeting criteria for inclusion in the systematic review. Results: Designs, populations, treatments, and inventories were extremely diverse. Most therapies did not target dissociation specifically, although the results of this review suggest that PTSD patients who experience dissociative symptoms could benefit from trauma-focused treatments, which often significantly reduced dissociative and trauma-related symptoms. Conclusion: Future work should consider the evaluation of dissociation as a unique outcome to gain understanding about the nature of traumatic stress and to develop treatment options for its many presentations. The current literature displays limited generalizability to the treatment of individuals with high dissociation, which is a line of inquiry that should be explored. More RCTs are needed.

Dissociative symptoms predict severe illness presentation in Canadian public safety personnel with presumptive post-traumatic stress disorder (PTSD)

BACKGROUND

Post-traumatic stress disorder affects 9% of individuals across their lifetime and increases nearly fourfold to 35% in Canadian public safety personnel (PSP). On-the-job experiences of PSP frequently meet criteria for traumatic events, making these individuals highly vulnerable to exposures of trauma and the negative consequences of PTSD. Few studies have reported on the clinical characteristics of Canadian samples of PSP and even fewer have examined the dissociative subtype of PTSD, which is associated with more severe, chronic traumatic experiences, and worse outcomes.

OBJECTIVE

This study aimed to characterize dissociative symptoms, PTSD symptom severity, and other clinical variables among Canadian PSP with presumptive PTSD.

METHODS

We sampled current and past PSP in Canada from both inpatient and outpatient populations (N = 50) that were enrolled in a psychological intervention. Only baseline testing data (prior to any intervention) were analysed in this study, such as PTSD symptom severity, dissociative symptoms, emotion dysregulation, and functional impairment.

RESULTS

In our sample, 24.4% self-reported elevated levels of dissociation, specifically symptoms of depersonalization and derealization. Depersonalization and derealization symptoms were associated with more severe PTSD symptoms, greater emotion dysregulation, and functional impairment.

CONCLUSIONS

Nearly a quarter of this sample of Canadian PSP reported experiencing elevated levels of PTSD-related dissociation (depersonalization and derealization). These high levels of depersonalization and derealization were consistently positively associated with greater illness severity across clinical measures. It is imperative that dissociative symptoms be better recognized in patient populations that are exposed to chronic traumatic events such as PSP, so that treatment interventions can be designed to target a more severe illness presentation.

Peripersonal Space and Bodily Self-Consciousness: Implications for Psychological Trauma-Related Disorders

Peripersonal space (PPS) is defined as the space surrounding the body where we can reach or be reached by external entities, including objects or other individuals. PPS is an essential component of bodily self-consciousness that allows us to perform actions in the world (e.g., grasping and manipulating objects) and protect our body while interacting with the surrounding environment. Multisensory processing plays a critical role in PPS representation, facilitating not only to situate ourselves in space but also assisting in the localization of external entities at a close distance from our bodies. Such abilities appear especially crucial when an external entity (a sound, an object, or a person) is approaching us, thereby allowing the assessment of the salience of a potential incoming threat. Accordingly, PPS represents a key aspect of social cognitive processes operational when we interact with other people (for example, in a dynamic dyad). The underpinnings of PPS have been investigated largely in human models and in animals and include the operation of dedicated multimodal neurons (neurons that respond specifically to co-occurring stimuli from different perceptive modalities, e.g., auditory and tactile stimuli) within brain regions involved in sensorimotor processing (ventral intraparietal sulcus, ventral premotor cortex), interoception (insula), and visual recognition (lateral occipital cortex). Although the defensive role of the PPS has been observed in psychopathology (e.g., in phobias) the relation between PPS and altered states of bodily consciousness remains largely unexplored. Specifically, PPS representation in trauma-related disorders, where altered states of consciousness can involve dissociation from the body and its surroundings, have not been investigated. Accordingly, we review here: (1) the behavioral and neurobiological literature surrounding trauma-related disorders and its relevance to PPS; and (2) outline future research directions aimed at examining altered states of bodily self-consciousness in trauma related-disorders.

[Combat stress and organic brain injury: type of the dynamics of posttraumatic stress disorder]

OBJECTIVE

To study a role of traumatic brain injury (TBI) in the development of posttraumatic stress disorder (PTSD) in ex combatants.

MATERIAL AND METHODS

Eighty-seven ex combatants were studied. The duration of follow-up was 15-18 years. The diagnosis was established in accordance with ICD-10 criteria. Patients were stratified by diagnosis into main group (PTSD) and comparison group (organic brain injury with reduced symptoms of PTSD ). A psychopathological method and a battery of questionnaires and scales, including those adapted for assessment of consequences of combat trauma, were administered.

RESULTS AND CONCLUSION

Clinical presentations of both groups in posttraumatic period show the similarity and homogeneity of posttraumatic disorders in these groups. In the future, the pathogenetic role of TBI severity appears more clearly, which, depending on the severity, leads to the formation of an organic lesion of the brain or performs only a pathoplastic role, giving some features to the clinical picture of PTSD. It was found that the more severe the injury, the greater the likelihood of PTSD transition to organic brain damage. It is emphasized that PTSD treatment is a continuous, long-term, complex and graded process that includes pharmacotherapy, psychotherapy, psychosocial interventions.

Neural correlates of script-driven imagery in adolescents with interpersonal traumatic experiences: A pilot study

In adults, trauma imagery has proven to be a useful tool to assess the neural mechanisms of psychological trauma processing. In adolescents, heterogeneous results could be found for other tasks, however, a trauma imagery paradigm has not been evaluated. For this purpose, we investigated a trauma imagery paradigm with control scripts to assess neural correlates of traumatic experiences in youth. 15 adolescents, who had experienced a traumatic interpersonal event in the past and have developed clinically relevant symptoms, underwent an fMRI scan while listening to their individual trauma- versus two control scripts (positive/negative). We analysed a parametric contrast of the imagery phases (trauma > negative > positive) which revealed activity in the thalamus, dorsal anterior cingulate cortex, cuneus, dorsomedial prefrontal cortex and amygdala. Additionally, amygdala-activity correlated positively with depression-symptom-severity. Our data provide evidence for the feasibility of fMRI during a trauma imagery task in adolescents to investigate networks previously related to hyperarousal in adults with PTSD. Further, we demonstrate the specificity of the activated networks for trauma imagery as compared to imagery of other emotional situations. The task might be particularly useful to evaluate neural correlates of treatment in adolescents when hyperarousal is a target symptom.

Brain connectivity abnormalities in patients with functional (psychogenic nonepileptic) seizures: A systematic review

OBJECTIVES

The aim of the current endeavor was to systematically review the existing evidence on brain connectivity abnormalities in patients with functional seizures (FS).

METHODS

This systematic review was prepared according to the instructions of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. MEDLINE (accessed from PubMed) and Scopus from inception to April 4, 2020 were systematically searched. The following search strategy was implemented and these key words (in the title/abstract) were used: "connectivity" OR "network" AND "psychogenic" OR "dissociative" OR "nonepileptic".

RESULTS

Through the search strategy, we could identify eighteen articles. These studies have applied various methodologies and they could identify a variety of brain connectivity abnormalities in people with FS. However, none of these studies provided a high level of evidence. They were all small studies (none had a sample size of more than 21 patients). In addition, most of the studies did not match their cases and their controls with respect to the psychiatric comorbidities and other significant confounders.

CONCLUSION

Abnormal functional connectivity between emotion processing areas of the brain with regions involved in executive control and cognitive performance, and the functional connections of the anterior cingulate cortex are of major interest and may be involved in the pathophysiology of FS. Pursuing the concept of brain connectivity abnormalities in patients with FS and comparing the findings with well-matched controls in well-designed studies may result in a breakthrough in identifying the exact neurobiological origin of FS.

Inter-channel phase differences during sleep spindles are altered in Veterans with PTSD

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We assessed the spatiotemporal dynamics of slow and fast spindles in PTSD.

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Inter-channel phase differences during slow spindles were reduced in PTSD.

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This effect was reproducible across nights and subsamples of the study population.

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The spatiotemporal dynamics of fast spindles was not altered in PTSD.

Sleep disturbances are common complaints in patients with post-traumatic stress disorder (PTSD). To date, however, objective markers of PTSD during sleep remain elusive. Sleep spindles are distinctive bursts of brain oscillatory activity during non-rapid eye movement (NREM) sleep and have been implicated in sleep protection and sleep-dependent memory processes. In healthy sleep, spindles observed in electroencephalogram (EEG) data are highly synchronized across different regions of the scalp. Here, we aimed to investigate whether the spatiotemporal synchronization patterns between EEG channels during sleep spindles, as quantified by the phase-locking value (PLV) and the mean phase difference (MPD), are altered in PTSD. Using high-density (64-channel) EEG data recorded from 78 combat-exposed Veteran men (31 with PTSD and 47 without PTSD) during two consecutive nights of sleep, we examined group differences in the PLV and MPD for slow (10–13 Hz) and fast (13–16 Hz) spindles separately. To evaluate the reproducibility of our findings, we set apart the first 47 consecutive participants (18 with PTSD) for the initial discovery and reserved the remaining 31 participants (13 with PTSD) for replication analysis. In the discovery analysis, compared to the non-PTSD group, the PTSD group showed smaller MPDs during slow spindles between the frontal and centro-parietal channel pairs on both nights. We obtained reproducible results in the replication analysis in terms of statistical significance and effect size. The PLVs during slow or fast spindles did not significantly differ between groups. The reduced inter-channel phase difference during slow spindles in PTSD may reflect pathological changes in the underlying thalamocortical circuits. This novel finding, if independently validated, may prove useful in developing sleep-focused PTSD diagnostics and interventions.

Acute and Post-Traumatic Stress Disorders: A biased nervous system

Acute stress disorder and post-traumatic stress disorder are generally triggered by an exceptionally intense threat. The consequences of this traumatogenic situation are explored here in chronological order, from exposure to the threat to development of symptoms. Such a situation may disrupt the equilibrium between two fundamental brain circuits, referred to as the "defensive" and "cognitive". The defensive circuit triggers the stress response as well as the formation of implicit memory. The cognitive circuit triggers the voluntary response and the formation of explicit autobiographical memory. During a traumatogenic situation, the defensive circuit could be over-activated while cognitive circuit is under-activated. In the most severe cases, overactivation of the defensive circuit may cause its brutal deactivation, resulting in dissociation. Here, we address the underlying neurobiological mechanisms at every scale: from neurons to behaviors, providing a detailed explanatory model of trauma.

Reduced gray matter volume in the left prefrontal, occipital, and temporal regions as predictors for posttraumatic stress disorder: a voxel-based morphometric study

The concept of acute stress disorder (ASD) was introduced as a diagnostic entity to improve the identification of traumatized people who are likely to develop posttraumatic stress disorder (PTSD). Neuroanatomical models suggest that changes in the prefrontal cortex, amygdala, and hippocampus play a role in the development of PTSD. Using voxel-based morphometry, this study aimed to investigate the predictive power of gray matter volume (GMV) alterations for developing PTSD. The GMVs of ASD patients (n = 21) were compared to those of PTSD patients (n = 17) and healthy controls (n = 18) in whole-brain and region-of-interest analyses. The GMV alterations seen in ASD patients shortly after the traumatic event (T1) were also correlated with PTSD symptom severity and symptom clusters 4 weeks later (T2). Compared with healthy controls, the ASD patients had significantly reduced GMV in the left visual cortex shortly after the traumatic event (T1) and in the left occipital and prefrontal regions 4 weeks later (T2); no significant differences in GMV were seen between the ASD and PTSD patients. Furthermore, a significant negative association was found between the GMV reduction in the left lateral temporal regions seen after the traumatic event (T1) and PTSD hyperarousal symptoms 4 weeks later (T2). Neither amygdala nor hippocampus alterations were predictive for the development of PTSD. These data suggest that gray matter deficiencies in the left hemispheric occipital and temporal regions in ASD patients may predict a liability for developing PTSD.

Neural correlates of conceptual-level fear generalization in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) may develop when mechanisms for making accurate distinctions about threat relevance have gone awry. Generalization across conceptually related objects has been hypothesized based on clinical observation in PTSD, but the neural mechanisms remain unexplored. Recent trauma-exposed military veterans (n = 46) were grouped into PTSD (n = 23) and non-PTSD (n = 23). Participants learned to generalize fear across conceptual categories (animals or tools) of semantically related items that were partially reinforced by shock during functional magnetic resonance imaging. Conditioned fear learning was quantified by shock expectancy and skin conductance response (SCR). Relative to veteran controls, PTSD subjects exhibited a stronger neural response associated with fear generalization to the reinforced object category in the striatum, anterior cingulate cortex, amygdala, occipitotemporal cortex, and insula (Z > 2.3; p < 0.05; whole-brain corrected). Based on SCR, both groups generalized the shock contingency to the reinforced conceptual category, but learning was not significantly different between groups. We found that PTSD was associated with an enhanced neural response in fronto-limbic, midline, and occipitotemporal regions to a learned representation of threat that is based on previously established conceptual knowledge of the relationship between basic-level exemplars within a semantic category. Behaviorally, veterans with PTSD were somewhat slower to differentiate threat and safety categories as compared with trauma-exposed veteran controls owing in part to an initial overgeneralized behavioral response to the safe category. These results have implications for understanding how fear spreads across semantically related concepts in PTSD.

Neurofeedback self-regulating training in patients with Post traumatic stress disorder: A randomized controlled trial study protocol

Background

Post-traumatic stress disorder (PTSD) has become an important public health problem. However, the conventional therapeutic strategy, including pharmacotherapy and cognitive behavioral therapy, has limitations. Neurofeedback is a technique that utilizes electroencephalography (EEG) signaling to monitor human physiological functions and is widely used to treat patients with PTSD. The purpose of our study is to assess the efficacy and safety level of neurofeedback treatment in patients with PTSD using quantitative EEG.

Methods

This is a randomized, waitlist-controlled, assessor-blinded, clinical trial. Forty-six patients with PTSD will be randomly assigned at a 1:1 ratio into two groups. The participants in the treatment group will receive neurofeedback treatment for 50 min, twice a week, for 8 weeks (16 sessions). Quantitative EEG will be utilized to monitor the physiological functions and brain waves of the participants. A four-week follow-up period is planned. The participants in the control group will wait for 12 weeks. The primary outcome is the Korean version of PTSD Checklist-5 (PCL-5-K) score. The PCL-5-K scores on week 8 will be compared between the two groups. Anxiety, depression, insomnia, emotions, EEG, quality-of-life, and safety level will be assessed as secondary outcomes.

Discussion

This trial will describe a clinical research methodology for neurofeedback in patients with PTSD. The numerous subjective and objective secondary outcomes add to the value of this trial’s results. It will also suggest a therapeutic strategy for utilizing quantitative EEG in patients with PTSD. Our trial will provide basic evidence for the management of PTSD via an integrative treatment.

Trial registration

Clinical Research Information Service (CRIS): KCT0003271.

Investigating patterns of neural response associated with childhood abuse v. childhood neglect

BACKGROUND

Childhood maltreatment is robustly associated with increased risk of poor mental health outcome and changes in brain function. The authors investigated whether childhood experience of abuse (e.g. physical, emotional and sexual abuse) and neglect (physical and emotional deprivation) was differentially associated with neural reactivity to threat.

METHODS

Participants were drawn from an existing study and allocated to one of four groups based on self-report of childhood maltreatment experience: individuals with childhood abuse experiences (n = 70); individuals with childhood neglect experiences (n = 87); individuals with combined experience of childhood abuse and neglect (n = 50); and non-maltreated individuals (n = 207) propensity score matched (PSM) on gender, age, IQ, psychopathology and SES. Neural reactivity to facial cues signalling threat was compared across groups, allowing the differential effects associated with particular forms of maltreatment experience to be isolated.

RESULTS

Brain imaging analyses indicated that while childhood abuse was associated with heightened localised threat reactivity in ventral amygdala, experiences of neglect were associated with heightened reactivity in a distributed cortical fronto-parietal network supporting complex social and cognitive processing as well as in the dorsal amygdala. Unexpectedly, combined experiences of abuse and neglect were associated with hypo-activation in several higher-order cortical regions as well as the amygdala.

CONCLUSIONS

Different forms of childhood maltreatment exert differential effects in neural threat reactivity: while the effects of abuse are more focal, the effects of neglect and combined experiences of abuse are more distributed. These findings are relevant for understanding the range of psychiatric outcomes following childhood maltreatment and have implications for intervention.

The role of emotion dysregulation in negative affect reactivity to a trauma cue: Differential associations through elicited posttraumatic stress disorder symptoms

BACKGROUND

Recent research has linked emotion dysregulation with increases in subjective ratings of negative affect (NA reactivity) to trauma reminders, a central symptom of posttraumatic stress disorder (PTSD). The current study adds to this burgeoning line of research by exploring elicited PTSD symptoms as a mechanism explicating the relation between emotion dysregulation and NA reactivity following trauma cue exposure.

METHODS

Participants were 60 treatment-seeking marijuana users with insomnia symptoms who reported exposure to a traumatic event. Participants were administered questionnaires assessing emotion dysregulation, PTSD symptoms, and NA prior to and/or after listening to a personalized trauma script, and subsequently completed a diagnostic interview.

RESULTS

Results demonstrated that greater emotion dysregulation was associated with heightened NA reactivity through re-experiencing symptoms, but not avoidance or dissociation symptoms, even after accounting for past 30-day PTSD symptom severity and pre-trauma script NA. These effects were driven by the dimensions of emotion dysregulation characterized by nonacceptance of negative emotions and limited access to effective emotion regulation strategies.

LIMITATIONS

This study requires replication among other clinical samples, and is limited by use of self-report measures.

CONCLUSIONS

Findings provide novel empirical support for one mechanism through which emotion dysregulation may confer vulnerability to PTSD symptomology, and offer implications for refining PTSD treatments.

Emotional remodeling with oxytocin durably rescues trauma-induced behavioral and neuro-morphological changes in rats: a promising treatment for PTSD

Recent evidence indicates that reactivated memories are malleable and can integrate new information upon their reactivation. We injected rats with oxytocin to investigate whether the delivery of a drug which dampens anxiety and fear before the reactivation of trauma memory decreases the emotional load of the original representation and durably alleviates PTSD-like symptoms. Rats exposed to the single prolonged stress (SPS) model of PTSD were classified 15 and 17 days later as either resilient or vulnerable to trauma on the basis of their anxiety and arousal scores. Following 2 other weeks, they received an intracerebral infusion of oxytocin (0.1 µg/1 µL) or saline 40 min before their trauma memory was reactivated by exposure to SPS reminders. PTSD-like symptoms and reactivity to PTSD-related cues were examined 3-14 days after oxytocin treatment. Results showed that vulnerable rats treated with saline exhibited a robust PTSD syndrome including increased anxiety and decreased arousal, as well as intense fear reactions to SPS sensory and contextual cues. Exposure to a combination of those cues resulted in c-fos hypo-activation and dendritic arbor retraction in prefrontal cortex and amygdala neurons, relative to resilient rats. Remarkably, 83% of vulnerable rats subjected to oxytocin-based emotional remodeling exhibited a resilient phenotype, and SPS-induced morphological alterations in prelimbic cortex and basolateral amygdala were eliminated. Our findings emphasize the translational potential of the present oxytocin-based emotional remodeling protocol which, when administered even long after the trauma, produces deep re-processing of traumatic memories and durable attenuation of the PTSD symptomatology.

Structural brain changes with lifetime trauma and re-experiencing symptoms is 5-HTTLPR genotype-dependent

Background: Findings on structural brain alterations following trauma are inconsistent due probably to heterogeneity in imaging studies and population, clinical presentations, genetic vulnerability, and selection of controls. This study examines whether trauma and re-experiencing symptoms are associated with specific alterations in grey matter volumes and if this varies according to 5-HTTLPR genotype. Methods: Structural MRI was used to acquire anatomical scans from 377 community-dwelling older adults. Quantitative regional estimates of 22 subregional volumes were derived using FreeSurfer software. Lifetime trauma was assessed using the validated Watson's PTSD inventory, which evaluates the most severe trauma experienced according to DSM criteria. Analyses adjusted for age, sex, total brain volume, head injury, and comorbidities. Results: Of the 212 participants reporting lifetime trauma, 35.4% reported re-experiencing symptoms and for 1.9%, this was severe enough to meet criteria for full threshold PTSD. In participants with the SS 5-HTTLPR genotype only, re-experiencing symptoms were associated with smaller volumes in middle and superior temporal, frontal (lateral orbital, rostral and caudal middle) and parietal (precuneus, inferior and superior) regions. The trauma-exposed participants without re-experiencing symptoms were not significantly different from the non-trauma-exposed participants except for smaller precuneus and superior parietal region in traumatized participants and a larger amygdala in traumatized women specifically. Conclusions: In the non-clinical sample, lifetime trauma and re-experiencing symptoms were associated with smaller volume in prefrontal, temporal and parietal cortex subregions, and this varied according to serotonergic genetic vulnerability, 5-HTTLPR SS individuals being most susceptible.

Childhood Maltreatment Alters the Neural Processing of Chemosensory Stress Signals

Accumulating evidence suggests that childhood maltreatment (CM) confers risk for psychopathology later in life by inducing hypervigilance to social threat cues such as fearful faces. However, it remains unclear whether the modulatory impact of CM extents to the olfactory domain of social communication in humans. To address this question, we examined whether CM modulates the neural processing of chemosensory threat signals in sweat and whether CM affects the stress-reducing effects of oxytocin (OXT) in this context. In a randomized, double-blind within-subject functional MRI study design, 58 healthy participants (30 females) received intranasal OXT (40 IU) or placebo (PLC) and completed a forced-choice emotion recognition task with faces of varying emotion intensities (neutral to fearful) while exposed to sweat stimuli and a non-social control odor. Axillary sweat samples were collected from 30 healthy male donors undergoing an acute psychosocial stressor (stress) and ergometer training (sport) as control in a pre-study. CM was assessed by the 25-item Childhood Trauma Questionnaire (CTQ). The final fMRI analysis included 50 healthy participants (26 females). Regression analysis showed a stress-specific association of CTQ scores with amygdala hyperreactivity, hippocampal deactivation, and increased functional connectivity between the amygdala and the hippocampus, medial orbitofrontal cortex, and the anterior cingulate cortex (ACC) under PLC. Furthermore, we observed a positive association of CTQ scores and the dampening effects of OXT on stress-related amygdala responses. Our findings suggest that CM may induce hypervigilance to chemosensory threat cues in a healthy sample due to inefficient frontolimbic inhibition of amygdala activation. Future studies should investigate whether increased recruitment of the intralimbic amygdala-hippocampus complex reflects a compensatory mechanism that prevents the development of psychopathology in those who have experienced CM. Furthermore, the results reveal that the stress-specific effects of OXT in the olfactory domain are more pronounced in participants with increasing levels of CM exposure.

Traumatic imagery following glucocorticoid administration in earthquake-related post-traumatic stress disorder: A preliminary functional magnetic resonance imaging study

OBJECTIVE

Post-traumatic stress disorder involves excessive retrieval of traumatic memories. Glucocorticoids impair declarative memory retrieval. This preliminary study examined the effect of acute hydrocortisone administration on brain activation in individuals with earthquake-related post-traumatic stress disorder compared with earthquake-exposed healthy individuals, during retrieval of traumatic memories.

METHOD

Participants exposed to earthquakes with (n = 11) and without post-traumatic stress disorder (n = 11) underwent two functional magnetic resonance imaging scans, 1-week apart, in a double-blind, placebo-controlled, counter-balanced design. On one occasion, they received oral hydrocortisone (20 mg), and on the other, placebo, 1 hour before scanning. Symptom provocation involved script-driven imagery (traumatic and neutral scripts) and measures of self-reported anxiety.

RESULTS

Arterial spin labelling showed that both post-traumatic stress disorder and trauma-exposed controls had significantly reduced cerebral blood flow in response to retrieval of traumatic versus neutral memories in the right hippocampus, parahippocampal gyrus, calcarine sulcus, middle and superior temporal gyrus, posterior cingulate, Heschl's gyrus, inferior parietal lobule, angular gyrus, middle occipital gyrus, supramarginal gyrus, lingual gyrus and cuneus, and the left prefrontal cortex. Hydrocortisone resulted in non-significant trends of increasing subjective distress and reduced regional cerebral blood flow in the left inferior frontal gyrus, left anterior cingulate gyrus, middle temporal gyrus, cerebellum, postcentral gyrus and right frontal pole, during the trauma script.

CONCLUSION

Findings do not fit with some aspects of the accepted neurocircuitry model of post-traumatic stress disorder, i.e., failure of the medial prefrontal cortex to quieten hyperresponsive amygdala activity, and the potential therapeutic benefits of hydrocortisone. They do, however, provide further evidence that exposure to earthquake trauma, regardless of whether post-traumatic stress disorder eventuates, impacts brain activity and highlights the importance of inclusion of trauma-exposed comparisons in studies of post-traumatic stress disorder.

Imaging of Posttraumatic Stress Disorder

This review summarizes current knowledge obtained from psychoradiological studies of posttraumatic stress disorder (PTSD). We first focus on 3 key anatomic structures (hippocampus, amygdala, and medial prefrontal cortex) and the functional circuits to which they contribute. In addition, we discuss the triple-network model, a widely accepted neurobiological model of PTSD that explains the vast majority of neuroimaging findings, as well as their interactions and relationships to functional disruptions in PTSD.

Opponent Effects of Hyperarousal and Re-experiencing on Affective Habituation in Posttraumatic Stress Disorder

BACKGROUND

Aberrant emotion processing is a hallmark of posttraumatic stress disorder (PTSD), with neurobiological models suggesting both heightened neural reactivity and diminished habituation to aversive stimuli. However, empirical work suggests that these response patterns may be specific to subsets of those with PTSD. This study investigates the unique contributions of PTSD symptom clusters (re-experiencing, avoidance and numbing, and hyperarousal) to neural reactivity and habituation to negative stimuli in combat-exposed veterans.

METHODS

Ninety-five combat-exposed veterans (46 with PTSD) and 53 community volunteers underwent functional magnetic resonance imaging while viewing emotional images. This study examined the relationship between symptom cluster severity and hemodynamic responses to negative compared with neutral images (NEG>NEU).

RESULTS

Veterans exhibited comparable mean and habituation-related responses for NEG>NEU, relative to civilians. However, among veterans, habituation, but not mean response, was differentially related to PTSD symptom severity. Hyperarousal symptoms were related to decreased habituation for NEG>NEU in a network of regions, including superior and inferior frontal gyri, ventromedial prefrontal cortex, superior and middle temporal gyri, and anterior insula. In contrast, re-experiencing symptoms were associated with increased habituation in a similar network. Furthermore, re-experiencing severity was positively related to amygdalar functional connectivity with the left inferior frontal gyrus and dorsal anterior cingulate cortex for NEG>NEU.

CONCLUSIONS

These results indicate that hyperarousal symptoms in combat-related PTSD are associated with decreased neural habituation to aversive stimuli. These impairments are partially mitigated in the presence of re-experiencing symptoms, such that during exposure to negative stimuli, re-experiencing symptoms are positively associated with amygdalar connectivity to prefrontal regions implicated in affective suppression.

Psychometric Properties of the Dissociative Subtype of PTSD Scale: Replication and Extension in a Clinical Sample of Trauma-Exposed Veterans

The addition of the dissociative subtype of posttraumatic stress disorder (PTSD) to the DSM-5 has spurred investigation of its genetic, neurobiological, and treatment response correlates. In order to reliably assess the subtype, we developed the Dissociative Subtype of PTSD Scale (DSPS; Wolf et al., 2017), a 15-item index of dissociative features. Our initial investigation of the dichotomous DSPS lifetime items in a veteran epidemiological sample demonstrated its ability to identify the subtype, supported a three-factor measurement structure, distinguished the three subscales from the normal-range trait of absorption, and demonstrated the greater contribution of derealization and depersonalization symptoms relative to other dissociative symptomatology. In this study, we replicated and extended these findings by administering self-report and interview versions of the DSPS, and assessing personality and PTSD in a sample of 209 trauma-exposed veterans (83.73% male, 57.9% with probable current PTSD). Results replicated the three-factor structure using confirmatory factor analysis of current symptom severity interview items, and the identification of the dissociative subtype (via latent profile analysis). Associations with personality supported the discriminant validity of the DSPS and suggested the subtype was marked by tendencies towards odd and unusual cognitive experiences and low positive affect. Receiver operating characteristic curves identified diagnostic cut-points on the DSPS to inform subtype classification, which differed across the interview and self-report versions. Overall, the DSPS performed well in psychometric analyses, and results support the utility of the measure in identifying this important component of posttraumatic psychopathology.

The effects of trauma on brain and body: A unifying role for the midbrain periaqueductal gray

Post-traumatic stress disorder (PTSD), a diagnosis that may follow the experience of trauma, has multiple symptomatic phenotypes. Generally, individuals with PTSD display symptoms of hyperarousal and of hyperemotionality in the presence of fearful stimuli. A subset of individuals with PTSD; however, elicit dissociative symptomatology (i.e., depersonalization, derealization) in the wake of a perceived threat. This pattern of response characterizes the dissociative subtype of the disorder, which is often associated with emotional numbing and hypoarousal. Both symptomatic phenotypes exhibit attentional threat biases, where threat stimuli are processed preferentially leading to a hypervigilant state that is thought to promote defensive behaviors during threat processing. Accordingly, PTSD and its dissociative subtype are thought to differ in their proclivity to elicit active (i.e., fight, flight) versus passive (i.e., tonic immobility, emotional shutdown) defensive responses, which are characterized by the increased and the decreased expression of the sympathetic nervous system, respectively. Moreover, active and passive defenses are accompanied by primarily endocannabinoid- and opioid-mediated analgesics, respectively. Through critical review of the literature, we apply the defense cascade model to better understand the pathological presentation of defensive responses in PTSD with a focus on the functioning of lower-level midbrain and extended brainstem systems.

The Dissociative Subtype of Post-traumatic Stress Disorder: Research Update on Clinical and Neurobiological Features

Recently, a dissociative subtype of post-traumatic stress disorder (PTSD) has been included in the DSM-5. This review focuses on the clinical and neurobiological features that distinguish the dissociative subtype of PTSD from non-dissociative PTSD. Clinically, the dissociative subtype of PTSD is associated with high PTSD severity, predominance of derealization and depersonalization symptoms, a more significant history of early life trauma, and higher levels of comorbid psychiatric disorders. Furthermore, PTSD patients with dissociative symptoms exhibit different psychophysiological and neural responses to the recall of traumatic memories. While individuals with non-dissociative PTSD exhibit an increased heart rate, decreased activation of prefrontal regions, and increased activation of the amygdala in response to traumatic reminders, individuals with the dissociative subtype of PTSD show an opposite pattern. It has been proposed that dissociation is a regulatory strategy to restrain extreme arousal in PTSD through hyperinhibition of limbic regions. In this research update, promises and pitfalls in current research studies on the dissociative subtype of PTSD are listed. Inclusion of the dissociative subtype of PTSD in the DSM-5 stimulates research on the prevalence, symptomatology, and neurobiology of the dissociative subtype of PTSD and poses a challenge to improve treatment outcome in PTSD patients with dissociative symptoms.