Social anxiety predicts amygdala activation in adolescents viewing fearful faces

Pre-scan state anxiety is associated with greater right amygdala-hippocampal response to fearful versus happy faces among trait-anxious Latina girls

BACKGROUND

Unfamiliarity with academic research may contribute to higher levels of anticipatory state anxiety about affective neuroimaging tasks. Children with high trait anxiety display differences in brain response to fearful facial affect compared to non-anxious youth, but little is known about the influence of state anxiety on this association. Because reduced engagement in scientific research and greater mistrust among minoritized groups may lead to systematic differences in pre-scan state anxiety, it is crucial to understand the neural correlates of state anxiety during emotion processing so as to disambiguate sources of individual differences.

METHODS

The present study probed the interactive effects of pre-scan state anxiety, trait anxiety, and emotional valence (fearful vs. happy faces) on neural activation during implicit emotion processing in a community sample of 46 preadolescent Latina girls (8-13 years).

RESULTS

Among girls with mean and high levels of trait anxiety, pre-scan state anxiety was associated with greater right amygdala-hippocampal and left inferior parietal lobe response to fearful faces relative to happy faces.

CONCLUSIONS

Anticipatory state anxiety in the scanning context may cause children with moderate and high trait anxiety to be hypervigilant to threats, further compounding the effects of trait anxiety. Neuroimaging researchers should control for state anxiety so that systematic differences in brain activation resulting from MRI apprehension are not misleadingly attributed to demographic or environmental characteristics.

Well-being is associated with cortical thickness network topology of human brain

BACKGROUND

Living a happy and meaningful life is an eternal topic in positive psychology, which is crucial for individuals' physical and mental health as well as social functioning. Well-being can be subdivided into pleasure attainment related hedonic well-being or emotional well-being, and self-actualization related eudaimonic well-being or psychological well-being plus social well-being. Previous studies have mostly focused on human brain morphological and functional mechanisms underlying different dimensions of well-being, but no study explored brain network mechanisms of well-being, especially in terms of topological properties of human brain morphological similarity network.

METHODS

Therefore, in the study, we collected 65 datasets including magnetic resonance imaging (MRI) and well-being data, and constructed human brain morphological network based on morphological distribution similarity of cortical thickness to explore the correlations between topological properties including network efficiency and centrality and different dimensions of well-being.

RESULTS

We found emotional well-being was negatively correlated with betweenness centrality in the visual network but positively correlated with eigenvector centrality in the precentral sulcus, while the total score of well-being was positively correlated with local efficiency in the posterior cingulate cortex of cortical thickness network.

CONCLUSIONS

Our findings demonstrated that different dimensions of well-being corresponded to different cortical hierarchies: hedonic well-being was involved in more preliminary cognitive processing stages including perceptual and attentional information processing, while hedonic and eudaimonic well-being might share common morphological similarity network mechanisms in the subsequent advanced cognitive processing stages.

A Mobile Application Adjunct to Augment Cognitive-Behavioral Group Therapy for Adolescents with Social Anxiety: Feasibility and Acceptability Results from the Wiring Adolescents with Social Anxiety via Behavioral Interventions Pilot Trial

Objective: Cognitive-Behavioral Group Therapy (CBGT) is an established treatment for Social Anxiety (SA). However, diagnostic recovery rate is only 20.5% in CBGT, and up to 50% of patients remain symptomatic posttreatment. Using videocalls to deliver digital CBGT (dCBGT) is feasible, cost-effective, and efficacious. Yet, the impact of dCBGT on social functioning remains limited, as dCBGT does not offer opportunities for monitoring cognition and behavior in social situations. Wiring Adolescents with Social Anxiety via Behavioral Interventions (WASABI), a clinician-assisted application that uses ecological momentary assessments (EMAs), cognitive bias tests, and clinical self-reports, was investigated as an adjunct to dCBGT. Methods: A prospective, parallel arm, double-blind randomized controlled trial was employed in 24 SA adolescents randomly assigned to dCBGT versus dCBGT plus WASABI. Results: Study completion rates (83%) and exit survey data indicated that WASABI is feasible and acceptable. Engagement with EMAs varied from four to 244 EMAs completed per person. Cognitive bias tests and clinical self-reports were completed at least weekly by 53% and 69% of participants, respectively. While standard tests did not reveal statistically significant differences between dCBGT plus WASABI and dCBGT alone, effect sizes were greater for dCBGT plus WASABI on symptom severity, social skills, and functioning. Conclusions: Despite the small sample, preliminary results suggest that WASABI is feasible, acceptable, and may be an effective augmentation tool for treating SA in teenagers.

Deep-SAGA: a deep-learning-based system for automatic gaze annotation from eye-tracking data

With continued advancements in portable eye-tracker technology liberating experimenters from the restraints of artificial laboratory designs, research can now collect gaze data from real-world, natural navigation. However, the field lacks a robust method for achieving this, as past approaches relied upon the time-consuming manual annotation of eye-tracking data, while previous attempts at automation lack the necessary versatility for in-the-wild navigation trials consisting of complex and dynamic scenes. Here, we propose a system capable of informing researchers of where and what a user's gaze is focused upon at any one time. The system achieves this by first running footage recorded on a head-mounted camera through a deep-learning-based object detection algorithm called Masked Region-based Convolutional Neural Network (Mask R-CNN). The algorithm's output is combined with frame-by-frame gaze coordinates measured by an eye-tracking device synchronized with the head-mounted camera to detect and annotate, without any manual intervention, what a user looked at for each frame of the provided footage. The effectiveness of the presented methodology was legitimized by a comparison between the system output and that of manual coders. High levels of agreement between the two validated the system as a preferable data collection technique as it was capable of processing data at a significantly faster rate than its human counterpart. Support for the system's practicality was then further demonstrated via a case study exploring the mediatory effects of gaze behaviors on an environment-driven attentional bias.

Anxiety and amygdala connectivity during movie-watching

Rodent and human studies have implicated an amygdala-prefrontal circuit during threat processing. One possibility is that while amygdala activity underlies core features of anxiety (e.g. detection of salient information), prefrontal cortices (i.e. dorsomedial prefrontal/anterior cingulate cortex) entrain its responsiveness. To date, this has been established in tightly controlled paradigms (predominantly using static face perception tasks) but has not been extended to more naturalistic settings. Consequently, using ‘movie fMRI’—in which participants watch ecologically-rich movie stimuli rather than constrained cognitive tasks—we sought to test whether individual differences in anxiety correlate with the degree of face-dependent amygdala-prefrontal coupling in two independent samples. Analyses suggested increased face-dependent superior parietal activation and decreased speech-dependent auditory cortex activation as a function of anxiety. However, we failed to find evidence for anxiety-dependent connectivity, neither in our stimulus-dependent or -independent analyses. Our findings suggest that work using experimentally constrained tasks may not replicate in more ecologically valid settings and, moreover, highlight the importance of testing the generalizability of neuroimaging findings outside of the original context.

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Using ‘movie fMRI’, we tested whether trait anxiety correlates with face-dependent amygdala-prefrontal coupling.

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We observed altered superior parietal activation to faces and auditory cortex activation to speech as a function of anxiety.

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We failed to find evidence for anxiety-dependent amygdala-dmPFC connectivity in stimulus-dependent or -independent analyses.

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Our findings highlight the importance of testing the generalizability of neuroimaging findings outside of the original context.

Altered gray matter volume and structural co-variance in adolescents with social anxiety disorder: evidence for a delayed and unsynchronized development of the fronto-limbic system

BACKGROUND

Social anxiety disorder (SAD) is a prevalent mental disorder diagnosed in childhood and adolescence. Theories regarding brain development and SAD suggest a close link between neurodevelopmental dysfunction at the adolescent juncture and SAD, but direct evidence is rare. This study aims to examine brain structural abnormalities in adolescents with SAD.

METHODS

High-resolution T1-weighted images were obtained from 31 adolescents with SAD (15-17 years) and 42 matching healthy controls (HC). We evaluated symptom severity with the Social Anxiety Scale for Children (SASC) and the Screen for Child Anxiety Related Emotional Disorders (SCARED). We used voxel-based morphometry analysis to detect regional gray matter volume abnormalities and structural co-variance analysis to investigate inter-regional coordination patterns.

RESULTS

We found significantly higher gray matter volume in the orbitofrontal cortex (OFC) and the insula in adolescents with SAD compared to HC. We also observed significant co-variance of the gray matter volume between the OFC and amygdala, and the OFC and insula in HC, but these co-variance relationships diminished in SAD.

CONCLUSIONS

These findings provide the first evidence that the brain structural deficits in adolescents with SAD are not only in the core regions of the fronto-limbic system, but also represented by the diminished coordination in the development of these regions. The delayed and unsynchronized development pattern of the fronto-limbic system supports SAD as an adolescent-sensitive developmental mental disorder.

Neural correlates of negative expectancy and impaired social feedback processing in social anxiety

Social anxiety has been associated with abnormalities in cognitive processing in the literature, manifesting as various cognitive biases. To what extent these biases interrupt social interactions remains largely unclear. This study used the Social Judgment Paradigm that could separate the expectation and experience stages of social feedback processing. Event-related potentials (ERPs) in these two stages were recorded to detect the effect of social anxiety that might not be reflected by behavioral data. Participants were divided into two groups according to their social anxiety level. Participants in the high social anxiety (HSA) group were more likely to predict that they would be socially rejected by peers than did their low social anxiety (LSA) counterparts (i.e. the control group). Compared to the ERP data of the LSA group, the HSA group showed: (a) a larger P1 component to social cues (peer faces) prior to social feedback presentation, possibly indicating an attention bias; (b) a difference in feedback-related negativity amplitude between unexpected social acceptance and unexpected social rejection, possibly indicating an expectancy bias; and (c) a diminished sensitivity of the P3 amplitude to social feedback valence (be accepted/be rejected), possibly indicating an experience bias. These results could help understand the cognitive mechanisms that comprise and maintain social anxiety.

Research Review: Pediatric anxiety disorders - what have we learnt in the last 10 years?

BACKGROUND

Anxiety disorders first emerge during the critical developmental periods of childhood and adolescence. This review synthesizes recent findings on the prevalence, risk factors, and course of the anxiety disorders; and their neurobiology and treatment.

METHODS

For this review, searches were conducted using PubMed, PsycINFO, and clinicaltrials.gov. Findings related to the epidemiology, neurobiology, risk factors, and treatment of pediatric anxiety disorders were then summarized.

FINDINGS

Anxiety disorders are high prevalence, and early-onset conditions associated with multiple risk factors including early inhibited temperament, environment stress, and structural and functional abnormalities in the prefrontal-amygdala circuitry as well as the default mode and salience networks. The anxiety disorders are effectively treated with cognitive behavioral therapy (CBT), selective serotonin reuptake inhibitors (SSRIs), and serotonin-norepinephrine reuptake inhibitors (SNRIs).

CONCLUSIONS

Anxiety disorders are high prevalence, early-onset conditions associated with a distinct neurobiological fingerprint, and are consistently responsive to treatment. Questions remain regarding who is at risk of developing anxiety disorders as well as the way in which neurobiology predicts treatment response.

A conceptual model of risk and protective factors associated with internalizing symptoms in autism spectrum disorder: A scoping review, synthesis, and call for more research

This paper reviews and synthesizes key areas of research related to the etiology, development, and maintenance of internalizing symptoms in children, adolescents, and adults with autism spectrum disorder (ASD). In developing an integrated conceptual model, we draw from current conceptual models of internalizing symptoms in ASD and extend the model to include factors related to internalizing within other populations (e.g., children that have experienced early life stress, children with other neurodevelopmental conditions, typically developing children) that have not been systematically examined in ASD. Our review highlights the need for more research to understand the developmental course of internalizing symptoms, potential moderators, and the interplay between early risk and protective factors. Longitudinal studies incorporating multiple methods and both environmental and biological factors will be important in order to elucidate these mechanisms.

Context matters: The role of subjective arousal during Attentional Bias Modification targeting socially anxious students

BACKGROUND AND OBJECTIVES

Attentional Bias Modification (ABM) paradigms targeting anxiety aim to reduce attentional biases for threatening stimuli and thereby reduce anxiety. Based on cognitive theories of performance and learning, elevated levels of arousal during ABM might enhance its effectiveness by making training more engaging and activating fear schemas. This study investigated whether elevated levels of arousal during ABM would increase its effectiveness in reducing attentional bias, stress reactivity, and post-event processing.

METHOD

We randomly assigned 79 high socially anxious students to a session of ABM or control training preceded by either a social stress or control induction to manipulate arousal. Training outcomes were attentional bias, stress reactivity, and post-event processing. Subjective arousal was assessed before, during, and after training.

RESULTS

Results indicated that ABM was not successful in reducing attentional bias, stress reactivity or post-event processing, and that the effects of ABM were not moderated by subjective arousal. There was a trend towards ABM being more effective than control training in reducing attentional bias directly after training when participants were more aroused. However, this effect was not maintained one day after the training.

LIMITATIONS

The arousal manipulation did not result in significant between-group differences in subjective arousal.

CONCLUSIONS

This study did not provide support for the moderating role of arousal in ABM training effects. Replications with more effective mood induction procedures and more power are needed as a trend finding was observed suggesting that higher levels of arousal improved the direct ABM effects on attentional bias.

Brain imaging findings in children and adolescents with mental disorders: A cross-sectional review

Background

While brain imaging studies of juvenile patients has expanded in recent years to investigate the cerebral neurophysiologic correlates of psychiatric disorders, this research field remains scarce. The aim of the present review was to cluster the main mental disorders according to the differential brain location of the imaging findings recently reported in children and adolescents reports. A second objective was to describe the worldwide distribution and the main directions of the recent magnetic resonance imaging (MRI) and positron tomography (PET) studies in these patients.

Methods

A survey of 423 MRI and PET articles published between 2005 and 2008 was performed. A principal component analysis (PCA), then an activation likelihood estimate (ALE) meta-analysis, were applied on brain regional information retrieved from articles in order to cluster the various disorders with respect to the cerebral structures where alterations were reported. Furthermore, descriptive analysis characterized the literature production.

Results

Two hundred and seventy-four articles involving children and adolescent patients were analyzed. Both the PCA and ALE methods clustered, three groups of diagnosed psychiatric disorders, according to the brain structural and functional locations: one group of affective disorders characterized by abnormalities of the frontal-limbic regions; a group of mental disorders with “cognition deficits” mainly related to cortex abnormalities; and one psychomotor condition associated with abnormalities in the basal ganglia. The descriptive analysis indicates a focus on attention deficit hyperactivity disorders and autism spectrum disorders, a general steady rise in the number of annual reports, and lead of US research.

Conclusion

This cross-sectional review of child and adolescent mental disorders based on neuroimaging findings suggests overlaps of brain locations that allow to cluster the diagnosed disorders into three sets with respectively marked affective, cognitive, and psychomotor phenomenology. Furthermore, the brain imaging research effort was unequally distributed across disorders, and did not reflect their prevalence.

Brain function and clinical characterization in the Boston adolescent neuroimaging of depression and anxiety study

We present a Human Connectome Project study tailored toward adolescent anxiety and depression. This study is one of the first studies of the Connectomes Related to Human Diseases initiative and is collecting structural, functional, and diffusion-weighted brain imaging data from up to 225 adolescents (ages 14-17 years), 150 of whom are expected to have a current diagnosis of an anxiety and/or depressive disorder. Comprehensive clinical and neuropsychological evaluations and longitudinal clinical data are also being collected. This article provides an overview of task functional magnetic resonance imaging (fMRI) protocols and preliminary findings (N = 140), as well as clinical and neuropsychological characterization of adolescents. Data collection is ongoing for an additional 85 adolescents, most of whom are expected to have a diagnosis of an anxiety and/or depressive disorder. Data from the first 140 adolescents are projected for public release through the National Institutes of Health Data Archive (NDA) with the timing of this manuscript. All other data will be made publicly-available through the NDA at regularly scheduled intervals. This article is intended to serve as an introduction to this project as well as a reference for those seeking to clinical, neurocognitive, and task fMRI data from this public resource.

A systematic review of treatments targeting cognitive biases in socially anxious adolescents: Special Section on "Translational and Neuroscience Studies in Affective Disorders" Section Editor, Maria Nobile MD, PhD

BACKGROUND

Adolescence is a period of brain plasticity that is affected by social and affective stimuli. Adaptive neurodevelopmental changes in the context of complex social situations may precipitate or exacerbate cognitive biases (i.e., attention and/or interpretation biases) and predispose at-risk individuals to symptoms of social anxiety.

METHODS

This systematic review followed the PRISMA guidelines. Nine adolescent studies were examined including 3 studies using Cognitive Bias Modification Training (CBMT) to target attention biases (CBMT-A), 3 studies using CBMT to target interpretation biases (CBMT-I), and 3 aimed at reducing both attention and interpretation biases.

RESULTS

The studies of CBMT-A alone did not find significant effects on cognitive and clinical outcomes. However, studies of CBMT-I alone showed some improvement in interpretation bias. The combination of CBMT-A and CBMT-I appeared promising in reducing both attentionl and interpretation biases.

LIMITATIONS

The paucity of studies and the heterogeneity across studies (e.g., format of CBMT, assessment measures) limit the calculation of overall effect sizes and the examination of predictors, moderators, and mediators of outcome.

CONCLUSIONS

Technology-driven interventions such as CBMT have the potential to extend treatments outside the clinic setting and to augment current therapies for social anxiety. Further research is needed to develop CBMT procedures that optimize learning in group and real-world settings and to identify predictors of treatment response. Understanding the neural correlates of response to CBMT may help identify future targets for intervention.

Autistic-traits, not anxiety, modulate implicit emotional guidance of attention in neurotypical adults

Although autistic and anxious traits are positively correlated, high levels of autistic traits are associated with poorer emotional guidance of attention (EGA) whilst high levels of anxious traits are associated with greater EGA. In order to better understand how these two trait dimensions influence EGA, we simultaneously examined the effects of anxiety and autistic traits in neurotypical adults on target identification in an attentional blink task. Analyses indicated that implicit EGA is attenuated in individuals with higher levels of autistic traits, but largely unaffected by variation in anxious traits. Our results suggest that anxiety plays a comparatively limited role in modulating implicit EGA and reinforces the importance of disentangling correlated individual differences when exploring the effects of personality, including emotional predisposition, on attention.

Higher resting-state BNST-CeA connectivity is associated with greater corrugator supercilii reactivity to negatively valenced images

The bed nucleus of the stria terminalis (BNST) and central nucleus of the amygdala (CeA) are hypothesized to be the output nodes of the extended amygdala threat response, integrating multiple signals to coordinate the threat response via outputs to the hypothalamus and brainstem. The BNST and CeA are structurally and functionally connected, suggesting interactions between these regions may regulate how the response to provocation unfolds. However, the relationship between human BNST-CeA connectivity and the behavioral response to affective stimuli is little understood. To investigate whether individual differences in BNST-CeA connectivity are related to the affective response to negatively valenced stimuli, we tested relations between resting-state BNST-CeA connectivity and both facial electromyographic (EMG) activity of the corrugator supercilii muscle and eyeblink startle magnitude during affective image presentation within the Refresher sample of the Midlife in the United States (MIDUS) study. We found that higher right BNST-CeA connectivity was associated with greater corrugator activity to negative, but not positive, images. There was a trend-level association between right BNST-CeA connectivity and trait negative affect. Eyeblink startle magnitude was not significantly related to BNST-CeA connectivity. These results suggest that functional interactions between BNST and CeA contribute to the behavioral response to negative emotional events.

Indices of association between anxiety and mindfulness: a guide for future mindfulness studies

Mindfulness and anxiety are often linked as inversely related traits and there have been several theoretical and mediational models proposed suggesting such a relationship between these two traits. The current review report offers an account of self-report measures, behavioral, electrophysiological, hemodynamic, and biological studies, which provide converging evidence for an inverse relationship between mindfulness and anxiety. To our knowledge, there are no comprehensive accounts of empirical evidence that investigate this relationship. After reviewing several empirical studies, we propose a schematic model, where a stressor can trigger the activation of amygdala which activates the hypothalamic-pituitary-adrenal (HPA) pathway. This hyperactive HPA axis leads to a cascade of psychological, behavioral, electrophysiological, immunological, endocrine, and genetic reactions in the body, primarily mediated by a sympathetic pathway. Conversely, mindfulness protects from deleterious effects of these triggered reactions by downregulating the HPA axis activity via a parasympathetic pathway. Finally, we propose a model suggesting a comprehensive scheme through which mindfulness and anxiety may interact through emotion regulation. It is recommended that future mindfulness intervention studies should examine a broad spectrum of measurement indices where possible, keeping logistic feasibility in mind and look at mindfulness in conjunction with anxiety rather than independently.

Beyond Emotions: Oscillations of the Amygdala and Their Implications for Electrical Neuromodulation

The amygdala is a structure involved in emotions, fear, learning and memory and is highly interconnected with other brain regions, for example the motor cortex and the basal ganglia that are often targets of treatments involving electrical stimulation. Deep brain stimulation of the basal ganglia is successfully used to treat movement disorders, but can carry along non-motor side effects. The origin of these non-motor side effects is not fully understood yet, but might be altered oscillatory communication between specific motor areas and the amygdala. Oscillations in various frequency bands have been detected in the amygdala during cognitive and emotional tasks, which can couple with oscillations in cortical regions or the hippocampus. However, data on oscillatory coupling between the amygdala and motor areas are still lacking. This review provides a summary of oscillation frequencies measured in the amygdala and their possible functional relevance in different species, followed by evidence for connectivity between the amygdala and motor areas, such as the basal ganglia and the motor cortex. We hypothesize that the amygdala could communicate with motor areas through coherence of low frequency bands in the theta-alpha range. Furthermore, we discuss a potential role of the amygdala in therapeutic approaches based on electrical stimulation.

Sex-Differentiated Associations among Negative Parenting, Emotion-Related Brain Function, and Adolescent Substance Use and Psychopathology Symptoms

Parenting is a critical factor in adolescent social-emotional development, with maladaptive parenting leading to risk for the development of psychopathology. However, the emotion-related brain mechanisms underlying the influence of parenting on psychopathology symptoms are unknown. The present study utilized functional magnetic resonance imaging and laboratory measures to examine sex-differentiated associations among parenting, adolescent emotion-related brain function, and substance use and psychopathology symptoms in 66 12-14 year olds. Maternal parenting behaviors (warmth, negative parenting) were observed in a laboratory task. Adolescent brain responses to negative emotional stimuli were assessed in emotion processing regions of interest (left [L] and right [R] amygdala, anterior insula, anterior cingulate cortex [ACC]). Adolescents reported on substance use and depressive, anxiety, and externalizing symptoms. Maternal negative parenting predicted adolescent brain activation differently by sex. For girls, negative parenting predicted heightened R ACC activation to negative emotional stimuli. For boys, negative parenting predicted blunted L and R anterior insula and L ACC activation. Furthermore, for girls, but not boys, heightened L anterior insula and heightened L and R ACC activation were associated with substance use and depressive symptoms, respectively. Findings suggest neural response to negative emotion as a possible sex-specific pathway from negative parenting to psychopathology.

Fear Network Model in Panic Disorder: The Past and the Future

The core concept for pathophysiology in panic disorder (PD) is the fear network model (FNM). The alterations in FNM might be linked with disturbances in the autonomic nervous system (ANS), which is a common phenomenon in PD. The traditional FNM included the frontal and limbic regions, which were dysregulated in the feedback mechanism for cognitive control of frontal lobe over the primitive response of limbic system. The exaggerated responses of limbic system are also associated with dysregulation in the neurotransmitter system. The neuroimaging studies also corresponded to FNM concept. However, more extended areas of FNM have been discovered in recent imaging studies, such as sensory regions of occipital, parietal cortex and temporal cortex and insula. The insula might integrate the filtered sensory information via thalamus from the visuospatial and other sensory modalities related to occipital, parietal and temporal lobes. In this review article, the traditional and advanced FNM would be discussed. I would also focus on the current evidences of insula, temporal, parietal and occipital lobes in the pathophysiology. In addition, the white matter and functional connectome studies would be reviewed to support the concept of advanced FNM. An emerging dysregulation model of fronto-limbic-insula and temporooccipito-parietal areas might be revealed according to the combined results of recent neuroimaging studies. The future delineation of advanced FNM model can be beneficial from more extensive and advanced studies focusing on the additional sensory regions of occipital, parietal and temporal cortex to confirm the role of advanced FNM in the pathophysiology of PD.

[Separation anxiety disorder in adults - a new diagnostic category]

Anxiety separation disorder (SAD) became the subject of increased attention of researchers in recent decades. DSM-5 and project of ICD-11 allow us to treat this disorder as an independent nosological unit without attachment to age. The review provides information on the prevalence, clinical manifestations and diagnosis of SAD in adults, summarizes information on the etiopathogenesis, relations to other psychiatric disorders, and highlights the lack of modern therapeutic approaches to SAD. The purpose of this review is to raise the level of knowledge about SAD and its new positioning in classification systems.

When change is the only constant: The promise of longitudinal neuroimaging in understanding social anxiety disorder

Longitudinal studies offer a unique window into developmental change. Yet, most of what we know about the pathophysiology of psychiatric disorders is based on cross-sectional work. Here, we highlight the importance of adopting a longitudinal approach in order to make progress towards identifying the neurobiological mechanisms of social anxiety disorder (SAD). Using examples, we illustrate how longitudinal data can uniquely inform SAD etiology and timing of interventions. The brain's inherently adaptive quality requires that we model risk correlates of disorders as dynamic in their expression. Developmental theories regarding timing of environmental events, cascading effects and (mal)adaptations of the developing brain will be crucial components of comprehensive, integrative models of SAD. We close by discussing analytical considerations when working with longitudinal, developmental data.

The effects of stimulus novelty and negativity on BOLD activity in the amygdala, hippocampus, and bed nucleus of the stria terminalis

The amygdala responds to stimulus novelty, which may correspond to an evaluation of novel stimuli for potential threat, and trait anxiety may modulate this response. The bed nucleus of the stria terminalis (BNST) may also be sensitive to novelty as it responds to both uncertainty and threat. If so, a BNST novelty response may also be affected by trait anxiety and interact with stimulus negativity. We presented participants with novel and repeated negative and neutral images while measuring brain activity via fMRI, and assessed participants’ self-reported trait anxiety. We expected to replicate past findings of novelty responses in the hippocampus and amygdala that are independent of stimulus negativity. We also expected BNST novelty-sensitivity and that trait anxiety would predict greater sensitivity to both novelty and negativity in the amygdala and BNST, but not the hippocampus. Our a priori analyses replicated past findings of a novelty response that was independent of valence in the hippocampus and amygdala. The BNST exhibited a novelty response for negative, but not neutral, images. Trait anxiety did not modulate the response to novelty or negativity in any of the ROIs investigated. Our findings suggest that the BNST plays a role in the detection of novelty.

Key words: novelty; bed nucleus of the stria terminalis; BNST; amygdale; fMRI; BST

A dimensional approach to determine common and specific neurofunctional markers for depression and social anxiety during emotional face processing

Major depression disorder (MDD) and anxiety disorder are both prevalent and debilitating. High rates of comorbidity between MDD and social anxiety disorder (SAD) suggest common pathological pathways, including aberrant neural processing of interpersonal signals. In patient populations, the determination of common and distinct neurofunctional markers of MDD and SAD is often hampered by confounding factors, such as generally elevated anxiety levels and disorder-specific brain structural alterations. This study employed a dimensional disorder approach to map neurofunctional markers associated with levels of depression and social anxiety symptoms in a cohort of 91 healthy subjects using an emotional face processing paradigm. Examining linear associations between levels of depression and social anxiety, while controlling for trait anxiety revealed that both were associated with exaggerated dorsal striatal reactivity to fearful and sad expression faces respectively. Exploratory analysis revealed that depression scores were positively correlated with dorsal striatal functional connectivity during processing of fearful faces, whereas those of social anxiety showed a negative association during processing of sad faces. No linear relationships between levels of depression and social anxiety were observed during a facial-identity matching task or with brain structure. Together, the present findings indicate that dorsal striatal neurofunctional alterations might underlie aberrant interpersonal processing associated with both increased levels of depression and social anxiety.

Flashing a smile: Startle eyeblink modulation by masked affective faces

Affective faces are important stimuli with relevance to healthy and abnormal social and affective information processing. The aim of this study was to investigate the effect of brief presentations of affective faces on attention and emotional state across the time course of stimulus processing, as indexed by startle eyeblink response modulation. Healthy adults were presented with happy, neutral, and disgusted male and female faces that were backward masked by neutral faces. Startle responses were elicited at 300, 800, and 3,500 ms following stimulus presentation to probe early and late startle eyeblink modulation, indicative of attention allocation and emotional state, respectively. Results revealed that, at 300 ms, both face expression and face gender modulated startle eyeblink response, suggesting that more attention was allocated to masked happy compared to disgusted female faces, and masked disgusted compared to neutral male faces. There were no effects of either face expression or face gender on startle modulation at 800 ms. At 3,500 ms, target face expression did not modulate startle, but male faces elicited larger startle responses than female faces, indicative of a more negative emotional state. These findings provide a systematic investigation of attention and emotion modulation by brief affective faces across the time course of stimulus processing.

Neural Reactivity to Angry Faces Predicts Treatment Response in Pediatric Anxiety

Although cognitive-behavioral psychotherapy (CBT) and pharmacotherapy are evidence-based treatments for pediatric anxiety, many youth with anxiety disorders fail to respond to these treatments. Given limitations of clinical measures in predicting treatment response, identifying neural predictors is timely. In this study, 35 anxious youth (ages 7-19 years) completed an emotional face-matching task during which the late positive potential (LPP), an event-related potential (ERP) component that indexes sustained attention towards emotional stimuli, was measured. Following the ERP measurement, youth received CBT or selective serotonin reuptake inhibitor (SSRI) treatment, and the LPP was examined as a predictor of treatment response. Findings indicated that, accounting for pre-treatment anxiety severity, neural reactivity to emotional faces predicted anxiety severity post- CBT and SSRI treatment such that enhanced electrocortical response to angry faces was associated with better treatment response. An enhanced LPP to angry faces may predict treatment response insofar as it may reflect greater emotion dysregulation or less avoidance and/or enhanced engagement with environmental stimuli in general, including with treatment.

Cognitive behavioural therapy attenuates the enhanced early facial stimuli processing in social anxiety disorders: an ERP investigation

Background

Previous studies of patients with social anxiety have demonstrated abnormal early processing of facial stimuli in social contexts. In other words, patients with social anxiety disorder (SAD) tend to exhibit enhanced early facial processing when compared to healthy controls. Few studies have examined the temporal electrophysiological event-related potential (ERP)-indexed profiles when an individual with SAD compares faces to objects in SAD. Systematic comparisons of ERPs to facial/object stimuli before and after therapy are also lacking. We used a passive visual detection paradigm with upright and inverted faces/objects, which are known to elicit early P1 and N170 components, to study abnormal early face processing and subsequent improvements in this measure in patients with SAD.

Methods

Seventeen patients with SAD and 17 matched control participants performed a passive visual detection paradigm task while undergoing EEG. The healthy controls were compared to patients with SAD pre-therapy to test the hypothesis that patients with SAD have early hypervigilance to facial cues. We compared patients with SAD before and after therapy to test the hypothesis that the early hypervigilance to facial cues in patients with SAD can be alleviated.

Results

Compared to healthy control (HC) participants, patients with SAD had more robust P1–N170 slope but no amplitude effects in response to both upright and inverted faces and objects. Interestingly, we found that patients with SAD had reduced P1 responses to all objects and faces after therapy, but had selectively reduced N170 responses to faces, and especially inverted faces. Interestingly, the slope from P1 to N170 in patients with SAD was flatter post-therapy than pre-therapy. Furthermore, the amplitude of N170 evoked by the facial stimuli was correlated with scores on the interaction anxiousness scale (IAS) after therapy.

Conclusions

Our results did not provide electrophysiological support for the early hypervigilance hypothesis in SAD to faces, but confirm that cognitive-behavioural therapy can reduce the early visual processing of faces. These findings have potentially important therapeutic implications in the assessment and treatment of social anxiety.

Trial registration HEBDQ2014021

Disentangling the effects of novelty, valence and trait anxiety in the bed nucleus of the stria terminalis, amygdala and hippocampus with high resolution 7T fMRI

The hippocampus and amygdala exhibit sensitivity to stimulus novelty that is reduced in participants with inhibited temperament, which is related to trait anxiety. Although the bed nucleus of the stria terminalis (BNST) is highly connected to the amygdala and is implicated in anxiety, whether the BNST responds to novelty remains unstudied, as well as how trait anxiety may modulate this response. Additionally how novelty, stimulus negativity and trait anxiety interact to affect activity in these areas is also unclear. To address these questions, we presented participants with novel and repeated, fearful and neutral faces, while measuring brain activity via fMRI, and also assessed participants' self-reported trait anxiety. As the small size of the BNST makes assessing its activity at typical fMRI resolution difficult, we employed high resolution 7 Tesla scanning. Our results replicate findings of novelty sensitivity that is independent of valence in the hippocampus. Our results also provide novel evidence for a BNST novelty response toward neutral, but not fearful faces. We also found that the novelty response in the hippocampus and BNST was blunted in participants with high trait anxiety. Additionally, we found left amygdala sensitivity to stimulus negativity that was blunted for high trait anxiety participants. These findings extend past research on the response to novel stimuli in the hippocampus and amygdala at high resolution, and are the first to demonstrate trait anxiety modulated novelty sensitivity in the BNST that is dependent on stimulus valence.

How does gaze direction affect facial processing in social anxiety? -An ERP study

Previous behavioral studies have demonstrated an effect of eye gaze direction on the processing of emotional expressions in adults with social anxiety. However, specific brain responses to the interaction between gaze direction and facial expressions in social anxiety remain unclear. The present study aimed to explore the time course of such interaction using event-related potentials (ERPs) in participants with social anxiety. High socially anxious individuals and low socially anxious individuals were asked to identify the gender of angry or neutral faces with direct or averted gaze while their behavioral performance and electrophysiological data were monitored. We found that identification of angry faces with direct but not averted gaze elicited larger N2 amplitude in high socially anxious individuals compared to low socially anxious individuals, while identification of neutral faces did not produce any gaze modulation effect. Moreover, the N2 was correlated with increased anxiety severity upon exposure to angry faces with direct gaze. Therefore, our results suggest that gaze direction modulates the processing of threatening faces in social anxiety. The N2 component elicited by angry faces with direct gaze could be a state-dependent biomarker of social anxiety and may be an important reference biomarker for social anxiety diagnosis and intervention.

Functional Connectivity of Multiple Brain Regions Required for the Consolidation of Social Recognition Memory

Social recognition memory is an essential and basic component of social behavior that is used to discriminate familiar and novel animals/humans. Previous studies have shown the importance of several brain regions for social recognition memories; however, the mechanisms underlying the consolidation of social recognition memory at the molecular and anatomic levels remain unknown. Here, we show a brain network necessary for the generation of social recognition memory in mice. A mouse genetic study showed that cAMP-responsive element-binding protein (CREB)-mediated transcription is required for the formation of social recognition memory. Importantly, significant inductions of the CREB target immediate-early genes c-fos and Arc were observed in the hippocampus (CA1 and CA3 regions), medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC), and amygdala (basolateral region) when social recognition memory was generated. Pharmacological experiments using a microinfusion of the protein synthesis inhibitor anisomycin showed that protein synthesis in these brain regions is required for the consolidation of social recognition memory. These findings suggested that social recognition memory is consolidated through the activation of CREB-mediated gene expression in the hippocampus/mPFC/ACC/amygdala. Network analyses suggested that these four brain regions show functional connectivity with other brain regions and, more importantly, that the hippocampus functions as a hub to integrate brain networks and generate social recognition memory, whereas the ACC and amygdala are important for coordinating brain activity when social interaction is initiated by connecting with other brain regions. We have found that a brain network composed of the hippocampus/mPFC/ACC/amygdala is required for the consolidation of social recognition memory.SIGNIFICANCE STATEMENT Here, we identify brain networks composed of multiple brain regions for the consolidation of social recognition memory. We found that social recognition memory is consolidated through CREB-meditated gene expression in the hippocampus, medial prefrontal cortex, anterior cingulate cortex (ACC), and amygdala. Importantly, network analyses based on c-fos expression suggest that functional connectivity of these four brain regions with other brain regions is increased with time spent in social investigation toward the generation of brain networks to consolidate social recognition memory. Furthermore, our findings suggest that hippocampus functions as a hub to integrate brain networks and generate social recognition memory, whereas ACC and amygdala are important for coordinating brain activity when social interaction is initiated by connecting with other brain regions.

A dimensional approach to modeling symptoms of neuropsychiatric disorders in the marmoset monkey

Some patients suffering from the same neuropsychiatric disorder may have no overlapping symptoms whilst others may share symptoms common to other distinct disorders. Therefore, the Research Domain Criteria initiative recognises the need for better characterisation of the individual symptoms on which to focus symptom-based treatment strategies. Many of the disorders involve dysfunction within the prefrontal cortex (PFC) and so the marmoset, due to their highly developed PFC and small size, is an ideal species for studying the neurobiological basis of the behavioural dimensions that underlie these symptoms.Here we focus on a battery of tests that address dysfunction spanning the cognitive (cognitive inflexibility and working memory), negative valence (fear generalisation and negative bias) and positive valence (anhedonia) systems pertinent for understanding disorders such as ADHD, Schizophrenia, Anxiety, Depression and OCD. Parsing the separable prefrontal and striatal circuits and identifying the selective neurochemical modulation (serotonin vs dopamine) that underlie cognitive dysfunction have revealed counterparts in the clinical domain. Aspects of the negative valence system have been explored both at individual- (trait anxiety and genetic variation in serotonin transporter) and circuit-based levels enabling the understanding of generalisation processes, negative biases and differential responsiveness to SSRIs. Within the positive valence system, the combination of cardiovascular and behavioural measures provides a framework for understanding motivational, anticipatory and consummatory aspects of anhedonia and their neurobiological mechanisms. Together, the direct comparison of experimental findings in marmosets with clinical studies is proving an excellent translational model to address the behavioural dimensions and neurobiology of neuropsychiatric symptoms. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 328-353, 2017.

Prefrontal Reactivity to Social Signals of Threat as a Predictor of Treatment Response in Anxious Youth

Neuroimaging has shown promise as a tool to predict likelihood of treatment response in adult anxiety disorders, with potential implications for clinical decision-making. Despite the relatively high prevalence and emergence of anxiety disorders in youth, very little work has evaluated neural predictors of response to treatment. The goal of the current study was to examine brain function during emotional face processing as a predictor of response to treatment in children and adolescents (age 7-19 years; N=41) with generalized, social, and/or separation anxiety disorder. Prior to beginning treatment with the selective serotonin reuptake inhibitor (SSRI) sertraline or cognitive behavior therapy (CBT), participants completed an emotional faces matching task during functional magnetic resonance imaging (fMRI). Whole brain responses to threatening (ie, angry and fearful) and happy faces were examined as predictors of change in anxiety severity following treatment. Greater activation in inferior and superior frontal gyri, including dorsolateral prefrontal cortex and ventrolateral prefrontal cortex, as well as precentral/postcentral gyri during processing of threatening faces predicted greater response to CBT and SSRI treatment. For processing of happy faces, activation in postcentral gyrus was a significant predictor of treatment response. Post-hoc analyses indicated that effects were not significantly moderated by type of treatment. Findings suggest that greater activation in prefrontal regions involved in appraising and regulating responses to social signals of threat predict better response to SSRI and CBT treatment in anxious youth and that neuroimaging may be a useful tool for predicting how youth will respond to treatment.

Altered Development of Amygdala-Anterior Cingulate Cortex Connectivity in Anxious Youth and Young Adults

BACKGROUND

Development of cortico-amygdala circuitry underlies the maturation of emotion processing and regulation, and age-related changes in amygdala connectivity with anterior cingulate cortex (ACC) have been shown to mediate normative developmental decreases in anxiety. It remains unclear whether developmental changes in this circuitry relate to pathological anxiety in youth. The current functional magnetic resonance imaging (fMRI) study addresses this question by examining amygdala functional connectivity in anxious and healthy individuals spanning the developmental period from childhood through adulthood.

METHODS

Youth and young adults (age 7-25) with current anxiety disorders (n=57) and healthy comparisons (n=61) completed an fMRI emotional face processing task known to elicit amygdala activation in youth and adults. We examined interaction effects of anxiety group and age on amygdala connectivity with frontolimbic regions during processing of happy, angry, and fearful faces.

RESULTS

Anxiety interacted with age to predict amygdala-ACC connectivity across emotional faces. Among healthy comparisons, age was negatively related to connectivity. In contrast, age was positively associated with amygdala-ACC connectivity in the anxious group. Group effects were also observed on amygdala connectivity with midcingulate and middle frontal gyri. Effects of anxiety and age on amygdala activation were not significant.

CONCLUSIONS

Results indicate that anxiety is characterized by altered patterns of age-related changes in amygdala connectivity during emotional face processing. Positive associations between age and amygdala-ACC connectivity among anxious youth and young adults may indicate failure to establish early bottom-up connections in childhood and/or less top-down regulation of the amygdala into adulthood.

Basic emotion processing and the adolescent brain: Task demands, analytic approaches, and trajectories of changes

Early neuroimaging studies suggested that adolescents show initial development in brain regions linked with emotional reactivity, but slower development in brain structures linked with emotion regulation. However, the increased sophistication of adolescent brain research has made this picture more complex. This review examines functional neuroimaging studies that test for differences in basic emotion processing (reactivity and regulation) between adolescents and either children or adults. We delineated different emotional processing demands across the experimental paradigms in the reviewed studies to synthesize the diverse results. The methods for assessing change (i.e., analytical approach) and cohort characteristics (e.g., age range) were also explored as potential factors influencing study results. Few unifying dimensions were found to successfully distill the results of the reviewed studies. However, this review highlights the potential impact of subtle methodological and analytic differences between studies, need for standardized and theory-driven experimental paradigms, and necessity of analytic approaches that are can adequately test the trajectories of developmental change that have recently been proposed. Recommendations for future research highlight connectivity analyses and non-linear developmental trajectories, which appear to be promising approaches for measuring change across adolescence. Recommendations are made for evaluating gender and biological markers of development beyond chronological age.

Comorbid Anxiety and Depressive Symptoms in Children and Adolescents: A Systematic Review and Analysis

BACKGROUND

A large and extensive body of research has examined comorbid anxiety and depression in adults. Children and adolescents also frequently present with comorbid anxiety and depression; however, research and treatment require unique environmental and neurodevelopmental considerations in children. As a result, our understanding of comorbid anxiety and depression in children and adolescents is limited.

OBJECTIVE

The goal of this systematic review was to examine the current literature focused on comorbid anxiety and depression in children and adolescents. The review included theoretical conceptualizations as well as diagnostic, neurobiological, prevention, and treatment considerations. In addition, a proposed algorithm for the treatment of comorbid anxiety and depression in children/adolescents is provided.

METHODS

This systematic literature review included 3 discrete searches in Ovid SP Medline, PsycInfo, and PubMed.

RESULTS

The review included and synthesized 115 articles published between 1987 and 2015. The available evidence suggests that anxiety and depression are common in clinical populations of children and adolescents, and that comorbidity is likely underestimated in children and adolescents. Children and adolescents with comorbid anxiety and depression have unique presentations, greater symptom severity, and treatment resistance compared with those who have either disease in isolation. A dimensional approach may be necessary for the future development of diagnostic strategies and treatments for this population. Nascent neuroimaging work suggests that anxiety and depression each represents a distinct neurobiological phenotype.

CONCLUSIONS

The literature that is currently available suggests that comorbid anxiety and depression is a common presentation in children and adolescents. This diagnostic picture underscores the importance of comprehensive dimensional assessments and multimodal evidence-based approaches given the high disease severity. Future research on the neurobiology and the treatment of these common clinical conditions is warranted.

Neural basis of uncertain cue processing in trait anxiety

Individuals with high trait anxiety form a non-clinical group with a predisposition for an anxiety-related bias in emotional and cognitive processing that is considered by some to be a prerequisite for psychiatric disorders. Anxious individuals tend to experience more worry under uncertainty, and processing uncertain information is an important, but often overlooked factor in anxiety. So, we decided to explore the brain correlates of processing uncertain information in individuals with high trait anxiety using the learn-test paradigm. Behaviorally, the percentages on memory test and the likelihood ratios of identifying novel stimuli under uncertainty were similar to the certain fear condition, but different from the certain neutral condition. The brain results showed that the visual cortex, bilateral fusiform gyrus, and right parahippocampal gyrus were active during the processing of uncertain cues. Moreover, we found that trait anxiety was positively correlated with the BOLD signal of the right parahippocampal gyrus during the processing of uncertain cues. No significant results were found in the amygdala during uncertain cue processing. These results suggest that memory retrieval is associated with uncertain cue processing, which is underpinned by over-activation of the right parahippocampal gyrus, in individuals with high trait anxiety.

Social anxiety disorder in adolescence: How developmental cognitive neuroscience findings may shape understanding and interventions for psychopathology

Social anxiety disorder represents a debilitating condition that has large adverse effects on the quality of social connections, educational achievement and wellbeing. Age-of-onset data suggests that early adolescence is a developmentally sensitive juncture for the onset of social anxiety. In this review, we highlight the potential of using a developmental cognitive neuroscience approach to understand (i) why there are normative increases in social worries in adolescence and (ii) how adolescence-associated changes may 'bring out' neuro-cognitive risk factors for social anxiety in a subset of individuals during this developmental period. We also speculate on how changes that occur in learning and plasticity may allow for optimal acquisition of more adaptive neurocognitive strategies through external interventions. Hence, for the minority of individuals who require external interventions to target their social fears, this enhanced flexibility could result in more powerful and longer-lasting therapeutic effects. We will review two novel interventions that target information-processing biases and their neural substrates via cognitive training and visual feedback of neural activity measured through functional magnetic resonance imaging.

Proneness to social anxiety modulates neural complexity in the absence of exposure: A resting state fMRI study using Hurst exponent

To test the hypothesis that brain activity is modulated by trait social anxiety, we measured the Hurst Exponent (HE), an index of complexity in time series, in healthy individuals at rest in the absence of any social trigger. Functional magnetic resonance imaging (fMRI) time series were recorded in 36 subjects at rest. All volunteers were healthy without any psychiatric, medical or neurological disorder. Subjects completed the Liebowitz Social Anxiety Scale (LSAS) and the Brief Fear of Negative Evaluation (BFNE) to assess social anxiety and thoughts in social contexts. We also obtained the fractional Amplitude of Low Frequency Fluctuations (fALFF) of the BOLD signal as an independent control measure for HE data. BFNE scores correlated positively with HE in the posterior cingulate/precuneus, while LSAS scores correlated positively with HE in the precuneus, in the inferior parietal sulci and in the parahippocamus. Results from fALFF were highly consistent with those obtained using LSAS and BFNE to predict HE. Overall our data indicate that spontaneous brain activity is influenced by the degree of social anxiety, on a continuum and in the absence of social stimuli. These findings suggest that social anxiety is a trait characteristic that shapes brain activity and predisposes to different reactions in social contexts.

Neural activation during anticipated peer evaluation and laboratory meal intake in overweight girls with and without loss of control eating

The interpersonal model of loss of control (LOC) eating proposes that socially distressing situations lead to anxious states that trigger excessive food consumption. Self-reports support these links, but the neurobiological underpinnings of these relationships remain unclear. We therefore examined brain regions associated with anxiety in relation to LOC eating and energy intake in the laboratory. Twenty-two overweight and obese (BMIz: 1.9±0.4) adolescent (15.8±1.6y) girls with LOC eating (LOC+, n=10) and without LOC eating (LOC-, n=12) underwent functional magnetic resonance imaging (fMRI) during a simulated peer interaction chatroom paradigm. Immediately after the fMRI scan, girls consumed lunch ad libitum from a 10,934-kcal laboratory buffet meal with the instruction to "let yourself go and eat as much as you want." Pre-specified hypotheses regarding activation of five regions of interest were tested. Analysis of fMRI data revealed a significant group by peer feedback interaction in the ventromedial prefrontal cortex (vmPFC), such that LOC+ had less activity following peer rejection (vs. acceptance), while LOC- had increased activity (p<.005). Moreover, functional coupling between vmPFC and striatum for peer rejection (vs. acceptance) interacted with LOC status: coupling was positive for LOC+, but negative in LOC- (p<.005). Activity of fusiform face area (FFA) during negative peer feedback from high-value peers also interacted with LOC status (p<.005). A positive association between FFA activation and intake during the meal was observed among only those with LOC eating. In conclusion, overweight and obese girls with LOC eating may be distinguished by a failure to engage regions of prefrontal cortex implicated in emotion regulation in response to social distress. The relationship between FFA activation and food intake supports the notion that heightened sensitivity to incoming interpersonal cues and perturbations in socio-emotional neural circuits may lead to overeating in order to cope with negative affect elicited by social discomfort in susceptible youth.

Neurostructural impact of co-occurring anxiety in pediatric patients with major depressive disorder: a voxel-based morphometry study

BACKGROUND

Depressive and anxiety disorders are among the most frequently occurring psychiatric conditions in children and adolescents and commonly present occur together. Co-occurring depression and anxiety is associated with increased functional impairment and suicidality compared to depression alone. Despite this, little is known regarding the neurostructural differences between anxiety disorders and major depressive disorder (MDD). Moreover, the neurophysiologic impact of the presence of anxiety in adolescents with MDD is unknown.

METHODS

Using voxel-based morphometry, gray matter volumes were compared among adolescents with MDD (and no co-morbid anxiety disorders, n=14), adolescents with MDD and co-morbid anxiety ("anxious depression," n=12), and healthy comparison subjects (n=41).

RESULTS

Patients with anxious depression exhibited decreased gray matter volumes in the dorsolateral prefrontal cortex (DLPFC) compared to patients with MDD alone. Compared to healthy subjects, adolescents with anxious depression had increased gray matter volumes in the pre- and post-central gyri.

LIMITATIONS

The current sample size was small and precluded an analysis of multiple covariates which may influence GMV.

CONCLUSIONS

Gray matter deficits in the DLPFC in youth with anxious depression compared to patients with MDD and no co-occurring anxiety may reflect the more severe psychopathology in these patients. Additionally, the distinct gray matter fingerprints of MDD and anxious depression (compared to healthy subjects) suggest differing neurophysiologic substrates for these conditions, though the etiology and longitudinal trajectory of the differences remain to be determined.

An fMRI study of emotional face processing in adolescent major depression

BACKGROUND

Major depressive disorder (MDD) often begins during adolescence when the brain is still maturing. To better understand the neurobiological underpinnings of MDD early in development, this study examined brain function in response to emotional faces in adolescents with MDD and healthy (HC) adolescents using functional magnetic resonance imaging (fMRI).

METHOD

Thirty-two unmedicated adolescents with MDD and 23 healthy age- and gender-matched controls completed an fMRI task viewing happy and fearful faces. Fronto-limbic regions of interest (ROI; bilateral amygdala, insula, subgenual and rostral anterior cingulate cortices) and whole-brain analyses were conducted to examine between-group differences in brain function.

RESULTS

ROI analyses revealed that patients had greater bilateral amygdala activity than HC in response to viewing fearful versus happy faces, which remained significant when controlling for comorbid anxiety. Whole-brain analyses revealed that adolescents with MDD had lower activation compared to HC in a right hemisphere cluster comprised of the insula, superior/middle temporal gyrus, and Heschl׳s gyrus when viewing fearful faces. Brain activity in the subgenual anterior cingulate cortex was inversely correlated with depression severity.

LIMITATIONS

Limitations include a cross-sectional design with a modest sample size and use of a limited range of emotional stimuli.

CONCLUSIONS

Results replicate previous studies that suggest emotion processing in adolescent MDD is associated with abnormalities within fronto-limbic brain regions. Findings implicate elevated amygdalar arousal to negative stimuli in adolescents with depression and provide new evidence for a deficit in functioning of the saliency network, which may be a future target for early intervention and MDD treatment.

Neural changes associated with emotion processing in children experiencing peer rejection: a functional MRI study

This study was performed to investigate differences between children who did and did not experience peer rejection in psychological state through surveys and in emotion processing during an interpersonal stress challenge task to reflect naturalistic interpersonal face-to-face relationships. A total of 20 right-handed children, 10 to 12 yr of age, completed self-rating questionnaires inquiring about peer rejection in school, depression, and anxiety. They then underwent an interpersonal stress challenge task simulating conditions of emotional stress, in reaction to positive, negative and neutral facial expression stimuli, using interpersonal feedbacks, and functional magnetic resonance imaging (FMRI) for an analysis of neural correlates during the task. Ten were the peer-rejection group, whereas the remainder were the control group. Based on the behavioral results, the peer-rejection group exhibited elevated levels of depression, state anxiety, trait anxiety and social anxiety as compared to the control group. The FMRI results revealed that the peer-rejection group exhibited greater and remarkably more extensive activation of brain regions encompassing the amygdala, orbitofrontal cortex and ventrolateral prefrontal cortex in response to negative feedback stimuli of emotional faces. The different brain reactivities characterizing emotion processing during interpersonal relationships may be present between children who do and do not experience peer rejection.

The impact of puberty and social anxiety on amygdala activation to faces in adolescence

Adolescence is associated with the onset of puberty, shifts in social and emotional behavior and an increased vulnerability to social anxiety disorder. These transitions coincide with changes in amygdala response to social and affective stimuli. Utilizing an emotional face-matching task, we examined amygdala response to peer-aged neutral and fearful faces in relation to puberty and social anxiety in a sample of 60 adolescent females between the ages of 8 and 15 years. We observed amygdala activation in response to both neutral and fearful faces compared to the control condition but did not observe differential amygdala activation between fearful and neutral faces. Right amygdala activity in response to neutral faces was negatively correlated with puberty and positively correlated with social anxiety, and these effects were statistically independent. Puberty and social anxiety did not relate to amygdala activation in response to fearful faces. These findings suggest that emotional differentiation between fearful and neutral faces may arise during later pubertal development and may result from decreasing sensitivity to neutral faces rather than increasing sensitivity to threatening faces. Furthermore, these findings highlight the importance of considering individual differences in social anxiety when examining the neural response to social stimuli in adolescents.

Neurobiology of Pediatric Anxiety Disorders

While the fear-based anxiety disorders (i.e., generalized anxiety disorder, social phobia and separation anxiety disorder) are among the most common psychiatric conditions in children and adolescents, only recently has an integrated understanding of the neurobiology of these disorders developed. In this regard, both structural and functional neuroimaging studies have demonstrated neuroanatomic and functional abnormalities within the amygdala and prefrontal cortex in youth with fear-based anxiety disorders, and have also suggested altered functional connectivity among components of the anterior limbic network (ALN), as well as alterations in neurochemistry within the anterior cingulate cortex. Additionally, several prefrontal structures and regions (e.g., medial prefrontal cortex) appear to be dysregulated in youth who are at risk of developing anxiety disorders (e.g., youth with inhibited temperament, behavioral inhibition, etc.). Finally, emerging data raise the possibility that functional activity within these amygdala-prefrontal networks may be affected by successful psychopharmacologic and psychotherapeutic treatment and may predict outcome.

Are you gonna leave me? Separation anxiety is associated with increased amygdala responsiveness and volume

The core feature of separation anxiety is excessive distress when faced with actual or perceived separation from people to whom the individual has a strong emotional attachment. So far little is known about the neurobiological underpinnings of separation anxiety. Therefore, we investigated functional (amygdala responsiveness and functional connectivity during threat-related emotion processing) and structural (grey matter volume) imaging markers associated with separation anxiety as measured with the Relationship Scale Questionnaire in a large sample of healthy adults from the Münster Neuroimaging Cohort (N = 320). We used a robust emotional face-matching task and acquired high-resolution structural images for morphometric analyses using voxel-based morphometry. The main results were positive associations of separation anxiety scores with amygdala reactivity to emotional faces as well as increased amygdala grey matter volumes. A functional connectivity analysis revealed positive associations between separation anxiety and functional coupling of the amygdala with areas involved in visual processes and attention, including several occipital and somatosensory areas. Taken together, the results suggest a higher emotional involvement in subjects with separation anxiety while watching negative facial expressions, and potentially secondary neuro-structural adaptive processes. These results could help to understand and treat (adult) separation anxiety.

Amygdala inputs to the ventral hippocampus bidirectionally modulate social behavior

Impairments in social interaction represent a core symptom of a number of psychiatric disease states, including autism, schizophrenia, depression, and anxiety. Although the amygdala has long been linked to social interaction, little is known about the functional role of connections between the amygdala and downstream regions in noncompetitive social behavior. In the present study, we used optogenetic and pharmacological tools in mice to study the role of projections from the basolateral complex of the amygdala (BLA) to the ventral hippocampus (vHPC) in two social interaction tests: the resident-juvenile-intruder home-cage test and the three chamber sociability test. BLA pyramidal neurons were transduced using adeno-associated viral vectors (AAV5) carrying either channelrhodopsin-2 (ChR2) or halorhodopsin (NpHR), under the control of the CaMKIIα promoter to allow for optical excitation or inhibition of amygdala axon terminals. Optical fibers were chronically implanted to selectively manipulate BLA terminals in the vHPC. NpHR-mediated inhibition of BLA-vHPC projections significantly increased social interaction in the resident-juvenile intruder home-cage test as shown by increased intruder exploration. In contrast, ChR2-mediated activation of BLA-vHPC projections significantly reduced social behaviors as shown in the resident-juvenile intruder procedure as seen by decreased time exploring the intruder and in the three chamber sociability test by decreased time spent in the social zone. These results indicate that BLA inputs to the vHPC are capable of modulating social behaviors in a bidirectional manner.