Paradoxical Prefrontal-Amygdala Recruitment to Angry and Happy Expressions in Pediatric Posttraumatic Stress Disorder

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

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

Adverse Life Experiences and Brain Function: A Meta-Analysis of Functional Magnetic Resonance Imaging Findings

Importance

Adverse life experiences have been proposed to contribute to diverse mental health problems through an association with corticolimbic functioning. Despite compelling evidence from animal models, findings from studies in humans have been mixed; activation likelihood estimation (ALE) meta-analyses have failed to identify a consistent association of adverse events with brain function.

Objective

To investigate the association of adversity exposure with altered brain reactivity using multilevel kernel density analyses (MKDA), a meta-analytic approach considered more robust than ALE to small sample sizes and methodological differences between studies.

Data Sources

Searches were conducted using PsycInfo, Medline, EMBASE, and Web of Science from inception through May 4, 2022. The following search term combinations were used for each database: trauma, posttraumatic stress disorder (PTSD), abuse, maltreatment, poverty, adversity, or stress; and functional magnetic resonance imaging (fMRI) or neuroimaging; and emotion, emotion regulation, memory, memory processing, inhibitory control, executive functioning, reward, or reward processing.

Study Selection

Task-based fMRI studies within 4 domains (emotion processing, memory processing, inhibitory control, and reward processing) that included a measure of adverse life experiences and whole-brain coordinate results reported in Talairach or Montreal Neurological Institute space were included. Conference abstracts, books, reviews, meta-analyses, opinions, animal studies, articles not in English, and studies with fewer than 5 participants were excluded.

Data Extraction and Synthesis

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline, 2 independent reviewers assessed abstracts and full-text articles for entry criteria. A third reviewer resolved conflicts and errors in data extraction. Data were pooled using a random-effects model and data analysis occurred from August to November 2022.

Main Outcomes and Measures

Peak activation x-axis (left-right), y-axis (posterior-anterior), and z-axis (inferior-superior) coordinates were extracted from all studies and submitted to MKDA meta-analyses.

Results

A total of 83 fMRI studies were included in the meta-analysis, yielding a combined sample of 5242 participants and 801 coordinates. Adversity exposure was associated with higher amygdala reactivity (familywise error rate corrected at P < .001; x-axis = 22; y-axis = -4; z-axis = -17) and lower prefrontal cortical reactivity (familywise error rate corrected at P < .001; x-axis = 10; y-axis = 60; z-axis = 10) across a range of task domains. These altered responses were only observed in studies that used adult participants and were clearest among those who had been exposed to severe threat and trauma.

Conclusions and Relevance

In this meta-analysis of fMRI studies of adversity exposure and brain function, prior adversity exposure was associated with altered adult brain reactivity to diverse challenges. These results might better identify how adversity diminishes the ability to cope with later stressors and produces enduring susceptibility to mental health problems.

Neural correlates of irritability symptom relief in adolescents pre- and post-trauma-focused cognitive behavioral therapy: A pilot study on reward processing

Despite that Trauma-Focused Cognitive Behavioral Therapy (TF-CBT) is a first-line, evidence-based treatment for youths experiencing trauma-related symptoms, treatment responses vary and it remains unclear for whom and how this treatment works. In this context, we examined pre-treatment neural reward processing and pre- vs. post-treatment changes in neural reward processing, in relation to irritability - a transdiagnostic and dimensional feature present in multiple trauma-related syndromes, following TF-CBT. Adolescents (N = 22) with childhood trauma history completed a child-friendly monetary incentive delay task during fMRI acquisition, prior to and after the treatment, and irritability symptoms were assessed at five time points over the course of the treatment. Individual irritability slopes (i.e., irritability change rate) and intercepts (i.e., initial irritability level), generated by linear growth curve modeling, were integrated with fMRI data. Repeated ANCOVAs demonstrated that both pre-treatment neural response to reward and pre- vs. post-treatment changes in neural reward processing correlated with irritability symptom relief, such that opposite baseline neural reward processing profiles and differential changing patterns were observed in individuals showing irritability symptom relief vs. not. Together, our findings provide proof of concept that integrating brain information with clinical information has the potential to identify predictors and mechanisms of symptom relief.

SAG treatment ameliorates memory impairment related to sleep loss by upregulating synaptic plasticity in adolescent mice

Adequate sleep during the developmental stage can promote learning and memory functions because synaptic protein synthesis at primed synapses during sleep profoundly affects neurological function. The Sonic hedgehog (Shh) signaling pathway affects neuroplasticity in the hippocampus during the development of the central nervous system. In this study, the changes in synaptic morphology and function induced by sleep deprivation and the potential therapeutic effect of a Shh agonist (SAG) on these changes were investigated in adolescent mice. Adolescent mice were subjected to sleep deprivation for 20 hrs (2pm to 10 am the next day) and were free to sleep for the remaining 4 hrs per day for 10 consecutive days. Sleep-deprived mice were injected with SAG (10mg/kg body weight, i.p.) or saline (i.p.) every day 5min before the onset of the 20h sleep deprivation period. Chronic sleep deprivation impaired recognition and spatial memory, decreased the number of dendritic spines and mEPSCs of hippocampal CA1 pyramidal neurons, decreased the postsynaptic density, and reduced Shh and glioma-associated oncogene homolog 1 (Gli1) expression. SAG significantly protected against sleep deprivation-induced memory dysfunction, increased the CA1 pyramidal neuronal dendritic spine number and mEPSC frequency, and increased Gli1 expression. In conclusion, sleep deprivation induces memory impairment in adolescent mice, and SAG treatment prevents this impairment, probably by enhancing synaptic function in the hippocampal CA1 region.

Towards assessing subcortical "deep brain" biomarkers of PTSD with functional near-infrared spectroscopy

Assessment of brain function with functional near-infrared spectroscopy (fNIRS) is limited to the outer regions of the cortex. Previously, we demonstrated the feasibility of inferring activity in subcortical "deep brain" regions using cortical functional magnetic resonance imaging (fMRI) and fNIRS activity in healthy adults. Access to subcortical regions subserving emotion and arousal using affordable and portable fNIRS is likely to be transformative for clinical diagnostic and treatment planning. Here, we validate the feasibility of inferring activity in subcortical regions that are central to the pathophysiology of posttraumatic stress disorder (PTSD; i.e. amygdala and hippocampus) using cortical fMRI and simulated fNIRS activity in a sample of adolescents diagnosed with PTSD (N = 20, mean age = 15.3 ± 1.9 years) and age-matched healthy controls (N = 20, mean age = 14.5 ± 2.0 years) as they performed a facial expression task. We tested different prediction models, including linear regression, a multilayer perceptron neural network, and a k-nearest neighbors model. Inference of subcortical fMRI activity with cortical fMRI showed high prediction performance for the amygdala (r > 0.91) and hippocampus (r > 0.95) in both groups. Using fNIRS simulated data, relatively high prediction performance for deep brain regions was maintained in healthy controls (r > 0.79), as well as in youths with PTSD (r > 0.75). The linear regression and neural network models provided the best predictions.

Gender diversity associated with patterns of brain activation seen in populations that experience childhood stress

Introduction

Stressful childhood experiences are associated with unique brain activity patterns during emotional processing. Specifically, pediatric stress is linked to activation in the insulae, superior temporal and parahippocampal gyri, and the amygdalae, as well as differential activation in the dorsal anterior cingulate cortex when viewing emotional faces. Gender diversity is broadly associated with higher victimization and mental health disparities in children aged 9/10, but whether it is associated with stress-like alterations in brain function (BOLD signal during task-based fMRI) remains unknown. We investigate the functional brain correlates of this relationship to determine if gender-diverse youth show patterns of functional activity during an emotional task consistent with those of other populations that experience heightened stress.

Methods

We used data from the Adolescent Brain Cognitive Development (ABCD)® study. First, we identified a subset of 4,385 participants aged 10/11 years with gender diversity data and quality-controlled fMRI data from the EN-Back (emotional n-back) task. The EN-Back is a working memory task that presents emotion faces as well as pictures of places as control stimuli. We regressed BOLD signal associated with emotion faces (faces minus places contrast) on gender diversity. Next, we tested if parental acceptance or youth perceptions of their school environment moderated the relationship between gender diversity and activation in the insulae or fusiform gyrus. Finally, we used structural equation modeling to investigate gender diversity's association with parental acceptance, perceptions of school environments, internalizing and externalizing problems.

Results

Gender diversity was associated with widespread increases in BOLD signal during the faces condition of the EN-Back task. Youth's report of parental acceptance and school environment did not moderate the relationship between gender diversity and BOLD signal in the insula or fusiform gyrus. Gender diversity was related to greater parent and school-related stress, which was associated with elevated mental health problems.

Conclusion

Patterns of functional activity were consistent with those reported in prior literature on childhood stress. Gender diversity was associated with increased emotional and behavioral problems, as well as parent and school-related stress. These findings indicate the importance of the home and school environments for supporting the wellbeing of gender diverse youth.

Childhood trauma and brain structure in children and adolescents

The dimensional model of adversity proposes that experiences of threat and deprivation have distinct neurodevelopmental consequences. We examined these dimensions, separately and jointly, with brain structure in a sample of 149 youth aged 8-17-half recruited based on exposure to threat-related experiences. We predicted that greater threat would be uniquely associated with reduced cortical thickness and surface area in brain regions associated with salience processing including ventromedial prefrontal cortex (vmPFC), anterior cingulate cortex (ACC), and insula, and that deprivation experiences would be uniquely associated with reductions in cortical thickness and surface area in frontoparietal areas associated with cognitive control. As predicted, greater threat was associated with thinner cortex in a network including areas involved in salience processing (anterior insula, vmPFC), and smaller amygdala volume (particularly in younger participants), after controlling for deprivation. Contrary to our hypotheses, threat was also associated with thinning in the frontoparietal control network. However, these associations were reduced following control for deprivation. No associations were found between deprivation and brain structure. This examination of deprivation and threat concurrently in the same sample provided further evidence that threat-related experiences influence the structure of the developing brain independent of deprivation.

The body keeps the score: The neurobiological profile of traumatized adolescents

Trauma-related disorders are debilitating psychiatric conditions that affect people who have directly or indirectly witnessed adversities. Experiencing multiple types of traumas appears to be common during childhood, and even more so during adolescence. Dramatic brain/body transformations occurring during adolescence may provide a highly responsive substrate to external stimuli and lead to trauma-related vulnerability conditions, such as internalizing (anxiety, depression, anhedonia, withdrawal) and externalizing (aggression, delinquency, conduct disorders) problems. Analyzing relations among neuronal, endocrine, immune, and biochemical signatures of trauma and internalizing and externalizing behaviors, including the role of personality traits in shaping these conducts, this review highlights that the marked effects of traumatic experience on the brain/body involve changes at nearly every level of analysis, from brain structure, function and connectivity to endocrine and immune systems, from gene expression (including in the gut) to the development of personality.

Childhood trauma, earlier pubertal timing, and psychopathology in adolescence: The role of corticolimbic development

Earlier pubertal development appears to be one pathway through which childhood trauma contributes to psychopathology in adolescence. Puberty-related changes in neural networks involved in emotion processing, namely the amygdala-medial prefrontal (mPFC) circuit, may be a potential mechanism linking trauma and adolescent psychopathology. Our participants were 227 youth between 10 and 13 years of age who completed assessments of threat and deprivation-related experiences of adversity, pubertal stage, and internalizing and externalizing symptoms. A subset (n = 149) also underwent a functional MRI scan while passively viewing fearful and calm faces. Potential mechanisms linking childhood trauma with psychopathology, encompassing earlier pubertal timing and neural response to aversive stimuli were explored. Earlier pubertal development was associated with childhood trauma as well as increased externalizing symptoms in boys only. Earlier pubertal timing in males and females was negatively associated with activation in bilateral amygdala, hippocampal, and fusiform regions when comparing fearful and calm faces. However, amygdala-mPFC connectivity showed no association with pubertal timing or psychopathology symptoms. These findings do not support accelerated amygdala-mPFC development as a mechanism linking childhood trauma and psychopathology, but instead provide support for the role of pubertal development in normative decreases in limbic activation across development.

Cortical activation predicts posttraumatic improvement in youth treated with TF-CBT or CCT

BACKGROUND

Identifying neural activation patterns that predict youths' treatment response may aid in the development of imaging-based assessment of emotion dysregulation following trauma and foster tailored intervention. Changes in cortical hemodynamic activity measured with functional near-infrared spectroscopy (fNIRS) may provide a time and cost-effective option for such work. We examined youths' PTSD symptom change following treatment and tested if previously identified activation patterns would predict treatment response.

METHODS

Youth (N = 73, mean age = 12.97, SD = 3.09 years) were randomly assigned to trauma-focused cognitive behavioral therapy (TF-CBT), cue-centered therapy (CCT), or treatment as usual (TAU). Parents and youth reported on youth's PTSD symptoms at pre-intervention, post-intervention, and follow-up. Neuroimaging data (N = 31) assessed at pre-intervention were obtained while youth engaged in an emotion expression task. Treatment response slopes were calculated for youth's PTSD symptoms.

RESULTS

Overall, PTSD symptoms decreased from pre-intervention through follow-up across conditions, with some evidence of relative benefit of TF-CBT and CCT over TAU but significant individual variation in treatment response. Cortical activation patterns were correlated with PTSD symptom improvement slopes (r = 0.53). In particular, cortical responses to fearful and neutral facial stimuli in six fNIRS channels in the bilateral dlPFC were important predictors of PTSD symptom improvement.

CONCLUSIONS

The use of fNIRS provides a method of monitoring and assessing cortical activation patterns in a relatively inexpensive and portable manner. Associations between functional activation and youths' PTSD symptoms improvement may be a promising avenue for understanding emotion dysregulation in clinical populations.

Posterior-prefrontal and medial orbitofrontal regions play crucial roles in happiness and sadness recognition

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Brain areas underlying trade-off relations between emotions were identified.

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Damage to the PPF area reduces accuracy of happiness recognition.

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Damage to the PPF increases accuracy of sadness recognition.

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A similar tendency was observed in orbitofrontal regions for sadness recognition.

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Only a deficit in sadness, but not happiness, persisted in the chronic phase.

The core brain regions responsible for basic human emotions are not yet fully understood. We investigated the key areas responsible for emotion recognition of facial expressions of happiness and sadness using data obtained from patients who underwent local brain resection. A total of 44 patients with right cerebral hemispheric brain tumors and 33 healthy volunteers were enrolled and subjected to a facial expression recognition test. Voxel-based lesion-symptom mapping was performed to investigate the relationship between the accuracy of emotion recognition and the resected regions. Consequently, trade-off relationships were discovered: the posterior-prefrontal region was related to a low score of happiness recognition and a high score of sadness recognition (disorder-of-happiness group), whereas the medial orbitofrontal region was related to a low score of sadness recognition and a high score of happiness recognition (disorder-of-sadness group). The emotion recognition score in both the happiness and sadness disorder groups was significantly lower than that in the control group (p = 0.0009 and p = 0.021, respectively). Interestingly, the deficit in happiness recognition was temporary, whereas the deficit in sadness recognition persisted during the chronic phase. Using graph theoretical analysis, we identified structural connectivity between the posterior-prefrontal and medial orbitofrontal regions. When either of these regions was damaged, the tract volume connecting them was significantly reduced (p = 0.013). These results indicate that the posterior-prefrontal and medial orbitofrontal regions may be crucial for maintaining a balance between happiness and sadness recognition in humans. Investigating the clinical impact of certain area resections using lesion studies combined with connectivity analysis is a useful neuroimaging method for understanding neural networks.

The relationship between recent PTSD secondary to sexual assault, hippocampal volume and resting state functional connectivity in adolescent girls

Objective

Improved understanding of the time course of neural changes associated with adolescent PTSD would elucidate the development of the disorder and could inform approaches to treatment. We compared hippocampal volumes and resting state functional connectivity (RSFC) in adolescent girls with post-traumatic stress disorder (PTSD) secondary to sexual assault, within six months of onset and age- and gender-matched, non-trauma exposed healthy controls (HCs) in São Paulo, Brazil. We also examined the relationship between pre- and post-treatment PTSD symptoms and RSFC.

Method

We collected brain structure, RSFC, and PTSD symptoms in 30 adolescents with PTSD (mean age: 15.7 ± 1.04 years) and 21 HCs (mean age: 16.2 ± 1.21 years) at baseline. We collected repeated measures in 21 participants with PTSD following treatment; 9 participants dropped out. Hippocampal volume and RSFC from hippocampal and default mode network (DMN) seeds were compared between participants with PTSD and HCs. We examined associations between within-subject changes in RSFC and PTSD symptoms following treatment.

Results

No hippocampal volumetric differences between groups were found. Compared to HCs, adolescents with recent PTSD had reduced RSFC between hippocampus and the lateral parietal node of the DMN, encompassing the angular gyrus, peak coordinates: −38, −54, 16; 116 voxels; peak F_1,47 = 31.76; FDR corrected p = 0.038. Improvements in PTSD symptoms were associated with increased RSFC between hippocampus and part of the lateral parietal node of the DMN, peak coordinates: −38, −84, 38; 316 voxels; peak F_1,47 = 40.28; FDR corrected p < 0.001.

Conclusion

Adolescents with recent PTSD had reduced hippocampal-DMN RSFC, while no group differences in hippocampal volume were found, suggesting that hippocampal function, but not structure, is altered early in the course of PSTD. Following treatment, hippocampal-DMN RSFC increased with symptom improvement and may indicate an important neural mechanism related to successful PTSD treatment.

Mapping structural covariance networks in children and adolescents with post-traumatic stress disorder after earthquake

For children and adolescents, there is a high risk of developing post-traumatic stress disorder (PTSD) after suffering from catastrophic events. Previous studies have identified brain functionally and subcortical brain volumes structurally abnormalities in this population. However, up till now, researches exploring alterations of regional cortical thickness (CTh) and brain interregional structural covariance networks (SCNs) are scarce. In this cross-sectional study, CTh measures are derived from 3-Tesla Tl-weighted MRI imaging data in a well-characterized combined group of children and adolescents with PTSD after an earthquake (N = 35) and a traumatized healthy control group (N = 24). By using surface-based morphometry (SBM) techniques, the regional CTh analysis was conducted. To map interregional SCNs derived from CTh, twenty-five altered brain regions reported in the PTSD population were selected as seeds. Whole-brain SBM analysis discovered a significant thickness reduction in the left medial orbitofrontal cortex for the subjects with PTSD. Similarly, analysis of SCNs associated with "seed" regions primarily located in default mode network (DMN), midline cortex structures, motor cortex, auditory association cortex, limbic system, and visual cortex demonstrated that children and adolescents with PTSD are associated with altered structural covariance with six key regions. This study provides evidence for distinct CTh correlates of PTSD that are present across children and adolescents, suggesting that brain cortical abnormalities related to trauma exposure are present in this population, probably by driving specific symptom clusters associated with disrupted extinction recall mechanisms for fear, episodic memory network and visuospatial attention.

Functional near-infrared spectroscopy brain imaging predicts symptom severity in youth exposed to traumatic stress

Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging technique with the potential to enable the assessment of posttraumatic stress disorder (PTSD) brain biomarkers in an affordable and portable manner. Consistent with biological models of PTSD, functional magnetic resonance imaging (fMRI) and fNIRS studies of adults with trauma exposure and PTSD symptoms suggest increased activation in the dorsolateral prefrontal cortex (dlPFC) and ventrolateral PFC (vlPFC) in response to negative emotion stimuli. We tested this theory with fNIRS assessment among youth exposed to traumatic stress and experiencing PTSD symptoms (PTSS). A portable fNIRS system collected hemodynamic responses from (N = 57) youth with PTSS when engaging in a classic emotion expression task that included fearful and neutral faces stimuli. The General Linear Model was applied to identify cortical activations associated with the facial stimuli. Subsequently, a prediction model was established via a Support Vector Regression to determine whether PTSS severity could be predicted based on fNIRS-derived cortical response measures and individual demographic information. Results were consistent with findings from adult fMRI and fNIRS studies of PTSS showing increased activation in the dlPFC and vlPFC in response to negative emotion stimuli. Subsequent prediction analysis revealed ten features (i.e., cortical responses from eight frontocortical fNIRS channels, age and sex) strongly correlated with PTSS severity (r = 0.65, p < .001). Our findings suggest the potential utility of fNIRS as a portable tool for the detection of putative PTSS brain biomarkers.

Mechanisms of neuroplasticity linking early adversity to depression: developmental considerations

Early exposure to psychosocial adversity is among the most potent predictors of depression. Because depression commonly emerges prior to adulthood, we must consider the fundamental principles of developmental neuroscience when examining how experiences of childhood adversity, including abuse and neglect, can lead to depression. Considering that both the environment and the brain are highly dynamic across the period spanning gestation through adolescence, the purpose of this review is to discuss and integrate stress-based models of depression that center developmental processes. We offer a general framework for understanding how psychosocial adversity in early life disrupts or calibrates the biobehavioral systems implicated in depression. Specifically, we propose that the sources and nature of the environmental input shaping the brain, and the mechanisms of neuroplasticity involved, change across development. We contend that the effects of adversity largely depend on the developmental stage of the organism. First, we summarize leading neurobiological models that focus on the effects of adversity on risk for mental disorders, including depression. In particular, we highlight models of allostatic load, acceleration maturation, dimensions of adversity, and sensitive or critical periods. Second, we expound on and review evidence for the formulation that distinct mechanisms of neuroplasticity are implicated depending on the timing of adverse experiences, and that inherent within certain windows of development are constraints on the sources and nature of these experiences. Finally, we consider other important facets of adverse experiences (e.g., environmental unpredictability, perceptions of one's experiences) before discussing promising research directions for the future of the field.

Safety learning during development: Implications for development of psychopathology

Fear and safety learning are necessary adaptive behaviors that develop over the course of maturation. While there is a large body of literature regarding the neurobiology of fear and safety learning in adults, less is known regarding safety learning during development. Given developmental changes in the brain, there are corresponding changes in safety learning that are quantifiable; these may serve to predict risk and point to treatment targets for fear and anxiety-related disorders in children and adolescents. For healthy, typically developing youth, the main developmental variation observed is reduced discrimination between threat and safety cues in children compared to adolescents and adults, while lower expression of extinction learning is exhibited in adolescents compared to adults. Such distinctions may be related to faster maturation of the amygdala relative to the prefrontal cortex, as well as incompletely developed functional circuits between the two. Fear and anxiety-related disorders, childhood maltreatment, and behavioral problems are all associated with alterations in safety learning for youth, and this dysfunction may proceed into adulthood with corresponding abnormalities in brain structure and function-including amygdala hypertrophy and hyperreactivity. As impaired inhibition of fear to safety may reflect abnormalities in the developing brain and subsequent psychopathology, impaired safety learning may be considered as both a predictor of risk and a treatment target. Longitudinal neuroimaging studies over the course of development, and studies that query change with interventions are needed in order to improve outcomes for individuals and reduce long-term impact of developmental psychopathology.

Neurobehavioral correlates of impaired emotion recognition in pediatric PTSD

Despite broad evidence suggesting that adversity-exposed youth experience an impaired ability to recognize emotion in others, the underlying biological mechanisms remains elusive. This study uses a multimethod approach to target the neurological substrates of this phenomenon in a well-phenotyped sample of youth meeting diagnostic criteria for posttraumatic stress disorder (PTSD). Twenty-one PTSD-afflicted youth and 23 typically developing (TD) controls completed clinical interview schedules, an emotion recognition task with eye-tracking, and an implicit emotion processing task during functional magnetic resonance imaging )fMRI). PTSD was associated with decreased accuracy in identification of angry, disgust, and neutral faces as compared to TD youth. Of note, these impairments occurred despite the normal deployment of visual attention in youth with PTSD relative to TD youth. Correlation with a related fMRI task revealed a group by accuracy interaction for amygdala-hippocampus functional connectivity (FC) for angry expressions, where TD youth showed a positive relationship between anger accuracy and amygdala-hippocampus FC; this relationship was reversed in youth with PTSD. These findings are a novel characterization of impaired threat recognition within a well-phenotyped population of severe pediatric PTSD. Further, the differential amygdala-hippocampus FC identified in youth with PTSD may imply aberrant efficiency of emotional contextualization circuits.

Early Adversity and Emotion Processing From Faces: A Meta-analysis on Behavioral and Neurophysiological Responses

BACKGROUND

Although the link between early adversity (EA) and later-life psychiatric disorders is well established, it has yet to be elucidated whether EA is related to distortions in the processing of different facial expressions. We conducted a meta-analysis to investigate whether exposure to EA relates to distortions in responses to different facial emotions at three levels: 1) event-related potentials of the P100 and N170, 2) amygdala functional magnetic resonance imaging responses, and 3) accuracy rate or reaction time in behavioral data.

METHODS

The systematic literature search (PubMed and Web of Science) up to April 2020 resulted in 29 behavioral studies (n = 8555), 32 functional magnetic resonance imaging studies (n = 2771), and 3 electroencephalography studies (n = 197) for random-effect meta-analyses.

RESULTS

EA was related to heightened bilateral amygdala reactivity to sad faces (but not other facial emotions). Exposure to EA was related to faster reaction time but a normal accuracy rate in response to angry and sad faces. In response to fearful and happy faces, EA was related to a lower accuracy rate only in individuals with recent EA exposure. This effect was more pronounced in individuals with exposure to EA before (vs. after) the age of 3 years. These findings were independent of psychiatric diagnoses. Because of the low number of eligible electroencephalography studies, no conclusions could be reached regarding the effect of EA on the event-related potentials.

CONCLUSIONS

EA relates to alterations in behavioral and neurophysiological processing of facial emotions. Our study stresses the importance of assessing age at exposure and time since EA because these factors mediate some EA-related perturbations.

Posttraumatic Stress Disorder and the Developing Adolescent Brain

Posttraumatic stress disorder (PTSD) in adolescents is common and debilitating. In contrast to adult PTSD, relatively little is known about the neurobiology of adolescent PTSD, nor about how current treatments may alter adolescent neurodevelopment to allow recovery from PTSD. Improving our understanding of biological mechanisms of adolescent PTSD, taken in the context of neurodevelopment, is crucial for developing novel and personalized treatment approaches. In this review, we highlight prevailing constructs of PTSD and current findings on these domains in adolescent PTSD. Notably, little data exist in adolescent PTSD for prominent adult PTSD constructs, including threat learning and attentional threat bias. Most work to date has examined general threat processing, emotion regulation, and their neural substrates. These studies suggest that adolescent PTSD, while phenomenologically similar to adult PTSD, shows unique neurodevelopmental substrates that may impair recovery but could also be targeted in the context of adolescent neuroplasticity to improve outcomes. Both cross-sectional and longitudinal data suggest abnormal frontolimbic development compared with typically developing youths, a pattern that may differ from resilient youths. Whether current treatments such as trauma-focused psychotherapy engage these targets and restore healthy neurodevelopment remains an open question. We end our review by highlighting emerging areas and knowledge gaps that could be addressed to better characterize the biology underlying adolescent PTSD. Emerging studies in computational modeling of decision making, caregiver-related transmission of traumatic stress, and other areas may offer new targets that could harness adolescent neurobehavioral plasticity to improve resilience and recovery for some of our most vulnerable youths.

Prenatal stress exposure and multimodal assessment of amygdala-medial prefrontal cortex connectivity in infants

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Non-human animal research shows stress alters amygdala–medial prefrontal cortex (mPFC) connectivity.

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It is unclear how prenatal stress may alter human infant connectivity.

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Prenatal stress was associated with decreased amygdala–mPFC functional connectivity.

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Prenatal stress was associated with increased amygdala–mPFC structural connectivity.

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This work provides insight into how stress contributes to neurodevelopmental risk.

Stressful experiences are linked to neurodevelopment. There is growing interest in the role of stress in the connectivity between the amygdala and medial prefrontal cortex (mPFC), a circuit that subserves automatic emotion regulation. However, the specific timing and mechanisms that underlie the association between stress and amygdala–mPFC connectivity are unclear. Many factors, including variations in fetal exposure to maternal stress, appear to affect early developing brain circuitry. However, few studies have examined the associations of stress and amygdala–mPFC connectivity in early life, when the brain is most plastic and sensitive to environmental influence. In this longitudinal pilot study, we characterized the association between prenatal stress and amygdala–mPFC connectivity in young infants (approximately age 5 weeks). A final sample of 33 women who provided data on preconception and prenatal stress during their pregnancy returned with their offspring for a magnetic resonance imaging scan session, which enabled us to characterize amygdala–mPFC structural and functional connectivity as a function of prenatal stress. Increased prenatal stress was associated with decreased functional connectivity and increased structural connectivity between the amygdala and mPFC. These results provide insight into the influence of prenatal maternal stress on the early development of this critical regulatory circuitry.

Biological aging in childhood and adolescence following experiences of threat and deprivation: A systematic review and meta-analysis

Life history theory argues that exposure to early life adversity (ELA) accelerates development, although existing evidence for this varies. We present a meta-analysis and systematic review testing the hypothesis that ELA involving threat (e.g., violence exposure) will be associated with accelerated biological aging across multiple metrics, whereas exposure to deprivation (e.g., neglect, institutional rearing) and low-socioeconomic status (SES) will not. We meta-analyze 54 studies (n = 116,010) examining associations of ELA with pubertal timing and cellular aging (telomere length and DNA methylation age), systematically review 25 studies (n = 3,253) examining ELA and neural markers of accelerated development (cortical thickness and amygdala-prefrontal cortex functional connectivity) and evaluate whether associations of ELA with biological aging vary according to the nature of adversity experienced. ELA overall was associated with accelerated pubertal timing (d = -0.10) and cellular aging (d = -0.21), but these associations varied by adversity type. Moderator analysis revealed that ELA characterized by threat was associated with accelerated pubertal development (d = -0.26) and accelerated cellular aging (d = -0.43), but deprivation and SES were unrelated to accelerated development. Systematic review revealed associations between ELA and accelerated cortical thinning, with threat-related ELA consistently associated with thinning in ventromedial prefrontal cortex, and deprivation and SES associated with thinning in frontoparietal, default, and visual networks. There was no consistent association of ELA with amygdala-PFC connectivity. These findings suggest specificity in the types of early environmental experiences associated with accelerated biological aging and highlight the importance of evaluating how accelerated aging contributes to health disparities and whether this process can be mitigated through early intervention. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

MRI Insights Into Adolescent Neurocircuitry-A Vision for the Future

Adolescence is the time of onset of many psychiatric disorders. Half of pediatric patients present with comorbid psychiatric disorders that complicate both their medical and psychiatric care. Currently, diagnosis and treatment decisions are based on symptoms. The field urgently needs brain-based diagnosis and personalized care. Neuroimaging can shed light on how aberrations in brain circuits might underlie psychiatric disorders and their development in adolescents. In this perspective article, we summarize recent MRI literature that provides insights into development of psychiatric disorders in adolescents. We specifically focus on studies of brain structural and functional connectivity. Ninety-six included studies demonstrate the potential of MRI to assess psychiatrically relevant constructs, diagnose psychiatric disorders, predict their development or predict response to treatment. Limitations of the included studies are discussed, and recommendations for future research are offered. We also present a vision for the role that neuroimaging may play in pediatrics and primary care in the future: a routine neuropsychological and neuropsychiatric imaging (NPPI) protocol for adolescent patients, which would include a 30-min brain scan, a quality control and safety read of the scan, followed by computer-based calculation of the structural and functional brain network metrics that can be compared to the normative data by the pediatrician. We also perform a cost-benefit analysis to support this vision and provide a roadmap of the steps required for this vision to be implemented.

Multi-voxel pattern analysis of amygdala functional connectivity at rest predicts variability in posttraumatic stress severity

INTRODUCTION

Resting state functional magnetic resonance imaging (rsfMRI) studies demonstrate that individuals with posttraumatic stress disorder (PTSD) exhibit atypical functional connectivity (FC) between the amygdala, involved in the generation of emotion, and regions responsible for emotional appraisal (e.g., insula, orbitofrontal cortex [OFC]) and regulation (prefrontal cortex [PFC], anterior cingulate cortex). Consequently, atypical amygdala FC within an emotional processing and regulation network may be a defining feature of PTSD, although altered FC does not seem constrained to one brain region. Instead, altered amygdala FC involves a large, distributed brain network in those with PTSD. The present study used a machine-learning data-driven approach, multi-voxel pattern analysis (MVPA), to predict PTSD severity based on whole-brain patterns of amygdala FC.

METHODS

Trauma-exposed adults (N = 90) completed the PTSD Checklist-Civilian Version to assess symptoms and a 5-min rsfMRI. Whole-brain FC values to bilateral amygdala were extracted and used in a relevance vector regression analysis with a leave-one-out approach for cross-validation with permutation testing (1,000) to obtain significance values.

RESULTS

Results demonstrated that amygdala FC predicted PCL-C scores with statistically significant accuracy (r = .46, p = .001; mean sum of squares = 130.46, p = .001; R²  = 0.21, p = .001). Prediction was based on whole-brain amygdala FC, although regions that informed prediction (top 10%) included the OFC, amygdala, and dorsolateral PFC.

CONCLUSION

Findings demonstrate the utility of MVPA based on amygdala FC to predict individual severity of PTSD symptoms and that amygdala FC within a fear acquisition and regulation network contributed to accurate prediction.

Altered large-scale functional brain organization in posttraumatic stress disorder: A comprehensive review of univariate and network-level neurocircuitry models of PTSD

Classical neural circuitry models of posttraumatic stress disorder (PTSD) are largely derived from univariate activation studies and implicate the fronto-limbic circuit as a main neural correlate of PTSD symptoms. Though well-supported by human neuroimaging literature, these models are limited in their ability to explain the widely distributed neural and behavioral deficits in PTSD. Emerging interest in the application of large-scale network methods to functional neuroimaging provides a new opportunity to overcome such limitations and conceptualize the neural circuitry of PTSD in the context of network patterns. This review aims to evaluate both the classical neural circuitry model and a new, network-based model of PTSD neural circuitry using a breadth of functional brain organization research in subjects with PTSD. Taken together, this literature suggests global patterns of reduced functional connectivity (FC) in PTSD groups as well as altered FC targets that reside disproportionately in canonical functional networks, especially the default mode network. This provides evidence for an integrative model that includes elements of both the classical models and network-based models to characterize the neural circuitry of PTSD.

Early Life Stress, Frontoamygdala Connectivity, and Biological Aging in Adolescence: A Longitudinal Investigation

Early life stress (ELS) may accelerate frontoamygdala development related to socioemotional processing, serving as a potential source of resilience. Whether this circuit is associated with other proposed measures of accelerated development is unknown. In a sample of young adolescents, we examined the relations among ELS, frontoamygdala circuitry during viewing of emotional faces, cellular aging as measured by telomere shortening, and pubertal tempo. We found that greater cumulative severity of ELS was associated with stronger negative coupling between bilateral centromedial amygdala and the ventromedial prefrontal cortex, a pattern that may reflect more mature connectivity. More negative frontoamygdala coupling (for distinct amygdala subdivisions) was associated with slower telomere shortening and pubertal tempo over 2 years. These potentially protective associations of negative frontoamygdala connectivity were most pronounced in adolescents who had been exposed to higher ELS. Our findings provide support for the formulation that ELS accelerates maturation of frontoamygdala connectivity and provide novel evidence that this neural circuitry confers protection against accelerated biological aging, particularly for adolescents who have experienced higher ELS. Although negative frontoamygdala connectivity may be an adaptation to ELS, frontoamygdala connectivity, cellular aging, and pubertal tempo do not appear to be measures of the same developmental process.

Keeping in Touch with Mental Health: The Orienting Reflex and Behavioral Outcomes from Calatonia

Physical and psychological therapy based on touch has been gradually integrated into broader mental health settings in the past two decades, evolving from a variety of psychodynamic, neurobiological and trauma-based approaches, as well as Eastern and spiritual philosophies and other integrative and converging systems. Nevertheless, with the exception of a limited number of well-known massage therapy techniques, only a few structured protocols of touch therapy have been standardized and researched to date. This article describes a well-defined protocol of touch therapy in the context of psychotherapy-the Calatonia technique-which engages the orienting reflex. The orienting reflex hypothesis is explored here as one of the elements of this technique that helps to decrease states of hypervigilance and chronic startle reactivity (startle and defensive reflexes) and restore positive motivational and appetitive states.

Commentary on the Special Issue on Network Analysis: Assessment, Intervention, Theory, and the Nature of Reality: Actualizing the Potential of Network Perspectives on Posttraumatic Stress Disorder

This commentary on the Journal of Traumatic Stress special issue on network analysis explores the network perspective on posttraumatic stress disorder (PTSD), emphasizing the advances in research made in this collection of articles. The commentary is organized around the following themes related to actualizing the perspective's methodological, assessment, and intervention potential and the potential shift in the theoretical underpinnings of mental disorders that networks models imply. First, extant data using network analysis suggest that reactions to traumatic stress are more complicated than once thought but that this complexity does not mean efficient, relatively simple heuristics to aid assessment and intervention do not exist. Attention to methodological issues in symptom assessment may help move this aspect of the research forward. Second, the extant research is largely correlational and has not yet established causal linkages, although temporal associations underlying network models are being identified. Prospective and intervention studies employing network analysis are critical. Third, the network perspective of PTSD symptoms may advance research on the mechanisms of risk and resilience (e.g., neurodevelopmental, cognitive behavioral, emotional, and social models) by helping link symptoms to theoretical causal processes. A developmental framework that views the effect of traumatic stress in terms of temporal cascades of reactions with both negative and potentially positive cognitive, behavioral, social, and emotional outcomes fits the network analysis model. Fourth, network models call into question some of the fundamental assumptions underlying the conceptualization of mental disorders, leaving several ontological questions and implications currently unanswered; research examining the implications of the new assumptions is needed.

Transcranial magnetic stimulation demonstrates a role for the ventrolateral prefrontal cortex in emotion perception

The lateral prefrontal cortex, a region with both structural and functional connectivity to the amygdala, has been consistently implicated in the downregulation of subcortical-generated emotional responses. Although previous work has demonstrated that the ventral lateral prefrontal cortex (vlPFC) is important to emotion processing, no study has interrupted vlPFC function in order to test is role in emotion perception. In the current study, we acutely disrupted vlPFC function in twenty healthy adult participants by administering sham stimulation and transcranial magnetic stimulation (TMS), in randomized order, during performance of an emotional perception task. During sham stimulation, participants demonstrated increased perceptual sensitivity for happy faces compared to angry faces. Disruption of the vlPFC eliminated this difference: in this condition, perceptual sensitivity did not differ between happy and angry faces. Reaction times and response bias did not differ between emotions or TMS conditions. This pattern of perceptual bias is consistent with effects observed in a wide range of affective disorders, in which vlPFC dysfunction has also been reported. This study provides insight into a possible mechanism through which the vlPFC may contribute to emotion perception.

Improved prediction of brain age using multimodal neuroimaging data

Brain age prediction based on imaging data and machine learning (ML) methods has great potential to provide insights into the development of cognition and mental disorders. Though different ML models have been proposed, a systematic comparison of ML models in combination with imaging features derived from different modalities is still needed. In this study, we evaluate the prediction performance of 36 combinations of imaging features and ML models including deep learning. We utilize single and multimodal brain imaging data including MRI, DTI, and rs‐fMRI from a large data set with 839 subjects. Our study is a follow‐up to the initial work (Liang et al., 2019. Human Brain Mapping) to investigate different analytic strategies to combine data from MRI, DTI, and rs‐fMRI with the goal to improve brain age prediction accuracy. Additionally, the traditional approach to predicting the brain age gap has been shown to have a systematic bias. The potential nonlinear relationship between the brain age gap and chronological age has not been thoroughly tested. Here we propose a new method to correct the systematic bias of brain age gap by taking gender, chronological age, and their interactions into consideration. As the true brain age is unknown and may deviate from chronological age, we further examine whether various levels of behavioral performance across subjects predict their brain age estimated from neuroimaging data. This is an important step to quantify the practical implication of brain age prediction. Our findings are helpful to advance the practice of optimizing different analytic methodologies in brain age prediction.

Longitudinal cortical markers of persistence and remission of pediatric PTSD

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Neural correlates of clinical outcomes in pediatric PTSD are poorly understood.

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Remission and persistence show unique patterns of cortical development over time.

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Nonremitters exhibit atypical decreases in prefrontal, parietal, and occipital CSA.

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PTSD remission was associated with cortical expansion in the prefrontal cortex.

Background

Previous studies have identified structural brain abnormalities in pediatric PTSD. However, little is known about what structural brain substrates may confer recovery versus persistence of PTSD in the context of the developing brain.

Methods

This naturalistic longitudinal study used T1-weighted MRI to evaluate cortical thickness and surface area in youth with a PTSD diagnosis (n = 28) and typically developing healthy youth (TD; n = 27) at baseline and one-year follow-up. Of the PTSD group, 10 youth were remitters at one-year follow up while 18 had persistent PTSD. Whole-brain estimates of cortical thickness and surface area were extracted to identify differences in cortical architecture associated with PTSD remission and persistence as compared to typical development.

Results

Youth who achieved PTSD remission entered the study with significantly lower trauma exposure and reduced symptom severity as compared to nonremitters. PTSD persistence was associated with decreased surface area over time in the ventrolateral prefrontal cortex (vlPFC) as compared to both remitters and TD youth. In contrast, PTSD remission was associated with expansion of frontal pole surface area and ventromedial PFC (vmPFC) thickness over time. Across clinical groups, vmPFC thickness was further inversely associated with symptom severity.

Conclusions

To our knowledge, these findings represent the first report of cortical substrates underlying persistence versus remission in pediatric PTSD. Together, these findings suggest active structural developmental processes unique to both remission and nonremission in youth with PTSD. In particular, expansion of prefrontal regions implicated in emotion regulation may facilitate recovery from PTSD in youth and would warrant further study.

Glycyrrhizin treatment ameliorates post-traumatic stress disorder-like behaviours and restores circadian oscillation of intracranial serotonin

Post-traumatic stress disorder (PTSD) has become a major disease that threatens human health. Neurotransmitters and the amygdala are found to be critical in the development and maintenance of PTSD. We aim to investigate the role of glycyrrhizin in treating PTSD. Contextual fear extinction and elevated plus maze test were applied to evaluate the anxiety and fear memory. Microdialysis and high-performance liquid chromatography were used to analyze the expression of amygdala neurotransmitters in PTSD animal models and to verify the effects of glycyrrhizin on major neurotransmitters. The protein levels of tryptophan hydroxylase 2 (TPH2) were examined by western bolt. Glycyrrhizin treatment significantly reduced anxiety and fear memory after 1 and 7 days of PTSD modelling. In addition, glycyrrhizin treatment restored the circadian rhythm changes of serotonin and TPH2. The present study found a significant circadian rhythm change of serotonin in the amygdala in PTSD rats. Besides, glycyrrhizin treatment restored the altered serotonin diurnal fluctuations, which raises important implications for PTSD treatment.

Longitudinal changes in brain function associated with symptom improvement in youth with PTSD

BACKGROUND

Previous studies indicate that youth with posttraumatic stress disorder (PTSD) have abnormal activation in brain regions important for emotion processing. It is unknown whether symptom improvement is accompanied by normative changes in these regions. This study identified neural changes associated with symptom improvement with the long-term goal of identifying malleable targets for interventions.

METHODS

A total of 80 functional magnetic resonance imaging (fMRI) scans were collected, including 20 adolescents with PTSD (ages 9-17) and 20 age- and sex-matched healthy control subjects, each scanned before and after a 5-month period. Trauma-focused cognitive behavioral therapy was provided to the PTSD group to ensure improvement in symptoms. Whole brain voxel-wise activation and region of interest analyses of facial expression task data were conducted to identify abnormalities in the PTSD group versus HC at baseline (BL), and neural changes correlated with symptom improvement from BL to EOS of study (EOS).

RESULTS

At BL, the PTSD group had abnormally elevated activation in the cingulate cortex, hippocampus, amygdala, and medial frontal cortex compared to HC. From BL to EOS, PTSD symptoms improved an average of 39%. Longitudinal improvement in symptoms of PTSD was associated with decreasing activation in posterior cingulate, mid-cingulate, and hippocampus, while improvement in dissociative symptoms was correlated with decreasing activation in the amygdala.

CONCLUSIONS

Abnormalities in emotion-processing brain networks in youth with PTSD normalize when symptoms improve, demonstrating neural plasticity of these regions in young patients and the importance of early intervention.

Annual Research Review: Pediatric posttraumatic stress disorder from a neurodevelopmental network perspective

BACKGROUND

Experiencing traumatic stress is common and may lead to posttraumatic stress disorder (PTSD) in a number of children and adolescents. Research using advanced imaging techniques is beginning to elucidate some of the neurobiological correlates of the traumatic stress response in youth.

METHODS

This paper summarizes the emerging network perspective of PTSD symptoms and reviews brain imaging research emphasizing structural and functional connectivity studies that employ magnetic resonance imaging techniques in pediatric samples.

RESULTS

Differences in structural connections and distributed functional networks such as the salience, default mode, and central executive networks are associated with traumatic and severe early life stress. The role of development has been relatively underappreciated in extant studies though there is evidence that critical brain regions as well as the structural and functional networks implicated undergo significant change in childhood and these typical developmental differences may be affected by traumatic stress.

CONCLUSIONS

Future research will benefit from adopting a truly developmental approach that considers children's growth as a meaningful effect (rather than simply a covariate) interacting with traumatic stress to predict disruptions in the anatomical, functional, and connective aspects of brain systems thought to underlie the network of PTSD symptoms. Linking symptom networks with neurodevelopmental network models may be a promising avenue for future work.

Chronic Stress Remodels Synapses in an Amygdala Circuit-Specific Manner

BACKGROUND

Chronic stress exposure increases the risk of developing various neuropsychiatric illnesses. The behavioral sequelae of stress correlate with dendritic hypertrophy and glutamate-related synaptic remodeling at basolateral amygdala projection neurons (BLA PNs). Yet, though BLA PNs are functionally heterogeneous with diverse corticolimbic targets, it remains unclear whether stress differentially impacts specific output circuits.

METHODS

Confocal imaging was used to reconstruct the morphology of mouse BLA PNs with the aid of retrograde tracing and biocytin staining. The synaptic activity in these neurons was measured with in vitro electrophysiology, and anxiety-like behavior of the mice was assessed with the elevated plus maze and open field test.

RESULTS

Chronic restraint stress (CRS) produced dendritic hypertrophy across mouse BLA PNs, regardless of whether they did (BLA→dorsomedial prefrontal cortex [dmPFC]) or did not (BLA↛dmPFC) target dmPFC. However, CRS increased the size of dendritic spine heads and the number of mature, mushroom-shaped spines only in BLA↛dmPFC PNs, sparing neighboring BLA→dmPFC PNs. Moreover, the excitatory glutamatergic transmission was also selectively increased in BLA↛dmPFC PNs, and this effect correlated with CRS-induced increases in anxiety-like behavior. Segregating BLA↛dmPFC PNs based on their targeting of ventral hippocampus (BLA→ventral hippocampus) or nucleus accumbens (BLA→nucleus accumbens) revealed that CRS increased spine density and glutamatergic signaling in BLA→ventral hippocampus PNs in a manner that correlated with anxiety-like behavior.

CONCLUSIONS

Chronic stress caused BLA PN neuronal remodeling with a previously unrecognized degree of circuit specificity, offering new insight into the pathophysiological basis of depression, anxiety disorders, and other stress-related conditions.

Does development moderate the effect of early life assaultive violence on resting-state networks? An exploratory study

Current neurocircuitry models of PTSD do not account for developmental effects, despite that early life assaultive violence is a potent risk factor for PTSD. Here, we preliminarily evaluated developmental stage as a moderator of the effect of early life assaultive violence on resting-state connectivity amongst regions associated with emotion generation and regulation using fMRI. Participants were adult women (n = 25) and adolescent girls (n = 36) who had or had not experienced early life assaultive violence. We found significant interactions between developmental stage and trauma exposure on resting-state functional connectivity (FC). Left amygdala connectivity with the left ventral anterior cingulate gyrus (BA 32) was reduced among trauma-exposed compared to control adolescents, but increased among trauma-exposed compared to control adults. A corresponding pattern of results was identified for FC between rostral anterior cingulate gyrus seed region and a similar right ventral anterior superior frontal gyrus cluster. Increased FC in both regions for assaulted adult women scaled positively with self-reported emotion regulation difficulties. Our results should be viewed tentatively due to sample limitations, but provide impetus to examine whether neurocircuitry models of PTSD may be strengthened by accounting for developmental stage.

Differential Roles of the Salience Network During Prediction Error Encoding and Facial Emotion Processing Among Female Adolescent Assault Victims

BACKGROUND

Early-life assaultive violence exposure is a potent risk factor for posttraumatic stress disorder (PTSD) and other mood and anxiety disorders. Neurocircuitry models posit that increased risk is mediated by heightened emotion processing in a salience network including the dorsal anterior cingulate cortex, anterior insula, and amygdala. However, the processes of reinforcement learning (RL) also engage the salience network and are implicated in responses to early-life trauma and PTSD. To define their relative roles in response to early-life trauma and PTSD symptoms, the current study compared engagement of the salience network during emotion processing and RL as a function of early-life assault exposure.

METHODS

Adolescent girls (n = 30 girls who had previously been physically or sexually assaulted; n = 30 healthy girls for comparison) 11 to 17 years of age completed two types of tasks during functional magnetic resonance imaging: a facial emotion processing task and an RL task using either social or nonsocial stimuli. Independent component analysis was used to identify a salience network and characterize its engagement in response to emotion processing and prediction error encoding during the RL tasks.

RESULTS

Assault was related to greater reactivity of the salience network during emotion processing. By contrast, we found lesser encoding of negative prediction errors in the salience network, particularly during the social RL task, in girls who had been assaulted. The dysfunction of salience network activity during emotion processing and prediction error encoding was not associated with PTSD symptoms.

CONCLUSIONS

These results suggest that hyper- versus hypoactivity of the salience network among trauma-exposed youths depends on the cognitive-affective domain.

Brain circuit dysfunction in post-traumatic stress disorder: from mouse to man

Post-traumatic stress disorder (PTSD) is a prevalent, debilitating and sometimes deadly consequence of exposure to severe psychological trauma. Although effective treatments exist for some individuals, they are limited. New approaches to intervention, treatment and prevention are therefore much needed. In the past few years, the field has rapidly developed a greater understanding of the dysfunctional brain circuits underlying PTSD, a shift in understanding that has been made possible by technological revolutions that have allowed the observation and perturbation of the macrocircuits and microcircuits thought to underlie PTSD-related symptoms. These advances have allowed us to gain a more translational knowledge of PTSD, have provided further insights into the mechanisms of risk and resilience and offer promising avenues for therapeutic discovery.

Abnormal Prefrontal Development in Pediatric Posttraumatic Stress Disorder: A Longitudinal Structural and Functional Magnetic Resonance Imaging Study

BACKGROUND

Prior studies of pediatric posttraumatic stress disorder (PTSD) have reported cross-sectional and age-related structural and functional brain abnormalities in networks associated with cognitive, affective, and self-referential processing. However, no reported studies have comprehensively examined longitudinal gray matter development and its intrinsic functional correlates in pediatric PTSD.

METHODS

Twenty-seven youths with PTSD and 21 nontraumatized typically developing (TD) youths were assessed at baseline and 1-year follow-up. At each visit, youths underwent structural magnetic resonance imaging and resting-state functional magnetic resonance imaging. Regions with volumetric abnormalities in whole-brain structural analyses were identified and used as seeds in exploratory intrinsic connectivity analyses.

RESULTS

Youths with PTSD exhibited sustained reductions in gray matter volume (GMV) in right ventromedial prefrontal cortex (PFC) and bilateral ventrolateral PFC. Group-by-time analyses revealed aberrant longitudinal development in dorsolateral PFC, where typically developing youths exhibited normative decreases in GMV between baseline and follow-up, and youths with PTSD showed increases in GMV. Using these regions as seeds, patients with PTSD exhibited atypical longitudinal decreases in intrinsic PFC-amygdala and PFC-hippocampus connectivity, in contrast to increases in typically developing youths. Specifically, youths with PTSD showed decreasing ventromedial PFC-amygdala connectivity as well as decreasing ventrolateral PFC-hippocampus connectivity over time. Notably, volumetric abnormalities in ventromedial PFC and ventrolateral PFC were predictive of symptom severity.

CONCLUSIONS

These findings represent novel longitudinal volumetric and connectivity changes in pediatric PTSD. Atypical prefrontal GMV and prefrontal-amygdala/hippocampus development may underlie persistence of PTSD in youths and could serve as future therapeutic targets.

Childhood Emotional Abuse Moderates Associations Among Corticomotor White Matter Structure and Stress Neuromodulators in Women With and Without Depression

Adverse caregiving during development can produce long-lasting changes to neural, endocrine, and behavioral responses to stress, and is strongly related to elevated risk of adult psychopathology. While prior experience of adversity is associated with altered sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis activity, the underlying neural pathways are not completely understood. In a double-blind crossover study, we used diffusion tensor imaging (DTI) to examine whether variation in white matter structure predicts differences in HPA-SNS interactions as a function of early adversity. Participants included 74 women who exhibited a wide range of depression severity and/or childhood emotional abuse (EA). Participants attended two experimental sessions during which they were administered 20 mg cortisol (CORT) or placebo and after 90 min, viewed emotionally laden pictures while undergoing MRI scanning. Immediately after emotional picture-viewing, we collected salivary alpha-amylase (sAA) to index SNS activation. We tested whether EA moderated the relation between fractional anisotropy (FA), a measure of white matter fiber structure, and sAA. In the placebo condition, for participants with minimal history of EA, higher FA in corticomotor projections was negatively correlated with sAA, whereas in participants with severe EA, the correlation was trending in the opposite direction. Following CORT administration, FA and sAA were not related, suggesting that SNS tone during acute cortisol elevation may depend on neural pathways other than corticomotor projections. The results suggest that at baseline—though not during cortisol elevation—increased FA in these tracts is associated with lower levels of SNS activity in women with minimal EA, but not in women with severe EA. These findings provide evidence that corticomotor projections may be a key component of altered neural circuitry in adults with history of maltreatment, and may be related to alterations in stress neuromodulators in psychopathology.

Psychopathy to Altruism: Neurobiology of the Selfish-Selfless Spectrum

The age-old philosophical, biological, and social debate over the basic nature of humans as being “universally selfish” or “universally good” continues today highlighting sharply divergent views of natural social order. Here we analyze advances in biology, genetics and neuroscience increasing our understanding of the evolution, features and neurocircuitry of the human brain underlying behavior in the selfish–selfless spectrum. First, we examine evolutionary pressures for selection of altruistic traits in species with protracted periods of dependence on parents and communities for subsistence and acquisition of learned behaviors. Evidence supporting the concept that altruistic potential is a common feature in human populations is developed. To go into greater depth in assessing critical features of the social brain, the two extremes of selfish–selfless behavior, callous unemotional psychopaths and zealous altruists who take extreme measures to help others, are compared on behavioral traits, structural/functional neural features, and the relative contributions of genetic inheritance versus acquired cognitive learning to their mindsets. Evidence from population groups ranging from newborns, adopted children, incarcerated juveniles, twins and mindfulness meditators point to the important role of neuroplasticity and the dopaminergic reward systems in forming and reforming neural circuitry in response to personal experience and cultural influences in determining behavior in the selfish–selfless spectrum. The underlying neural circuitry differs between psychopaths and altruists with emotional processing being profoundly muted in psychopaths and significantly enhanced in altruists. But both groups are characterized by the reward system of the brain shaping behavior. Instead of rigid assignment of human nature as being “universally selfish” or “universally good,” both characterizations are partial truths based on the segments of the selfish–selfless spectrum being examined. In addition, individuals and populations can shift in the behavioral spectrum in response to cognitive therapy and social and cultural experience, and approaches such as mindfulness training for introspection and reward-activating compassion are entering the mainstream of clinical care for managing pain, depression, and stress.

Trauma, PTSD, and the Developing Brain

PURPOSE OF REVIEW

PTSD in youth is common and debilitating. In contrast to adult PTSD, relatively little is known about the neurobiology of pediatric PTSD, nor how neurodevelopment may be altered. This review summarizes recent neuroimaging studies in pediatric PTSD and discusses implications for future study.

RECENT FINDINGS

Pediatric PTSD is characterized by abnormal structure and function in neural circuitry supporting threat processing and emotion regulation. Furthermore, cross-sectional studies suggest that youth with PTSD have abnormal frontolimbic development compared to typically developing youth. Examples include declining hippocampal volume, increasing amygdala reactivity, and declining amygdala-prefrontal coupling with age. Pediatric PTSD is characterized by both overt and developmental abnormalities in frontolimbic circuitry. Notably, abnormal frontolimbic development may contribute to increasing threat reactivity and weaker emotion regulation as youth age. Longitudinal studies of pediatric PTSD are needed to characterize individual outcomes and determine whether current treatments are capable of restoring healthy neurodevelopment.

Neurobiology of comorbid post-traumatic stress disorder and alcohol-use disorder

Post-traumatic stress disorder (PTSD) and alcohol-use disorder (AUD) are highly comorbid in humans. Although we have some understanding of the structural and functional brain changes that define each of these disorders, and how those changes contribute to the behavioral symptoms that define them, little is known about the neurobiology of comorbid PTSD and AUD, which may be due in part to a scarcity of adequate animal models for examining this research question. The goal of this review is to summarize the current state-of-the-science on comorbid PTSD and AUD. We summarize epidemiological data documenting the prevalence of this comorbidity, review what is known about the potential neurobiological basis for the frequent co-occurrence of PTSD and AUD and discuss successes and failures of past and current treatment strategies. We also review animal models that aim to examine comorbid PTSD and AUD, highlighting where the models parallel the human condition, and we discuss the strengths and weaknesses of each model. We conclude by discussing key gaps in our knowledge and strategies for addressing them: in particular, we (1) highlight the need for better animal models of the comorbid condition and better clinical trial design, (2) emphasize the need for examination of subpopulation effects and individual differences and (3) urge cross-talk between basic and clinical researchers that is reflected in collaborative work with forward and reverse translational impact.