Atypical modulation of medial prefrontal cortex to self-referential comments in generalized social phobia

A brain model of altered self-appraisal in social anxiety disorder

The brain's default mode network has a central role in the processing of information concerning oneself. Dysfunction in this self-referential processing represents a key component of multiple mental health conditions, particularly social anxiety disorder (SAD). This case-control study aimed to clarify alterations to network dynamics present during self-appraisal in SAD participants. A total of 38 adolescents and young adults with SAD and 72 healthy control participants underwent a self-referential processing fMRI task. The task involved two primary conditions of interest: direct self-appraisal (thinking about oneself) and reflected self-appraisal (thinking about how others might think about oneself). Dynamic causal modeling and parametric empirical Bayes were then used to explore differences in the effective connectivity of the default mode network between groups. We observed connectivity differences between SAD and healthy control participants in the reflected self-appraisal but not the direct self-appraisal condition. Specifically, SAD participants exhibited greater excitatory connectivity from the posterior cingulate cortex (PCC) to medial prefrontal cortex (MPFC) and greater inhibitory connectivity from the inferior parietal lobule (IPL) to MPFC. In contrast, SAD participants exhibited reduced intrinsic connectivity in the absence of task modulation. This was illustrated by reduced excitatory connectivity from the PCC to MPFC and reduced inhibitory connectivity from the IPL to MPFC. As such, participants with SAD showed changes to afferent connections to the MPFC which occurred during both reflected self-appraisal as well as intrinsically. The presence of connectivity differences in reflected and not direct self-appraisal is consistent with the characteristic fear of negative social evaluation that is experienced by people with SAD.

Neurocognitive Model of Schema-Congruent and -Incongruent Learning in Clinical Disorders: Application to Social Anxiety and Beyond

Negative schemas lie at the core of many common and debilitating mental disorders. Thus, intervention scientists and clinicians have long recognized the importance of designing effective interventions that target schema change. Here, we suggest that the optimal development and administration of such interventions can benefit from a framework outlining how schema change occurs in the brain. Guided by basic neuroscientific findings, we provide a memory-based neurocognitive framework for conceptualizing how schemas emerge and change over time and how they can be modified during psychological treatment of clinical disorders. We highlight the critical roles of the hippocampus, ventromedial prefrontal cortex, amygdala, and posterior neocortex in directing schema-congruent and -incongruent learning (SCIL) in the interactive neural network that comprises the autobiographical memory system. We then use this framework, which we call the SCIL model, to derive new insights about the optimal design features of clinical interventions that aim to strengthen or weaken schema-based knowledge through the core processes of episodic mental simulation and prediction error. Finally, we examine clinical applications of the SCIL model to schema-change interventions in psychotherapy and provide cognitive-behavior therapy for social anxiety disorder as an illustrative example.

Self-evaluation of social-rank in socially anxious individuals associates with enhanced striatal reward function

BACKGROUND

Negative self-views, especially in the domain of power (i.e. social-rank), characterize social anxiety (SA). Neuroimaging studies on self-evaluations in SA have mainly focused on subcortical threat processing systems. Yet, self-evaluation may concurrently invoke diverse affective processing, as motivational systems related to desired self-views may also be activated. To investigate the conflictual nature that may accompany self-evaluation of certain social domains in SA, we examined brain activity related to both threat and reward processing.

METHODS

Participants (N = 74) differing in self-reported SA-severity underwent fMRI while completing a self-evaluation task, wherein they judged the self-descriptiveness of high- v. low-intensity traits in the domains of power and affiliation (i.e. social connectedness). Participants also completed two auxiliary fMRI tasks designated to evoke reward- and threat-related activations in the ventral striatum (VS) and amygdala, respectively. We hypothesized that self-evaluations in SA, particularly in the domain of power, involve aberrant brain activity related to both threat and reward processing.

RESULTS

SA-severity was more negatively associated with power than with affiliation self-evaluations. During self-evaluative judgment of high-power (e.g. dominant), SA-severity associated with increased activity in the VS and ventromedial prefrontal cortex. Moreover, SA-severity correlated with higher similarity between brain activity patterns activated by high-power traits and patterns activated by incentive salience (i.e. reward anticipation) in the VS during the reward task.

CONCLUSIONS

Our findings indicate that self-evaluation of high-power in SA involves excessive striatal reward-related activation, and pinpoint the downregulation of VS-VMPFC activity within such self-evaluative context as a potential neural outcome for therapeutic interventions.

Topography of the Anxious Self: Abnormal Rest-Task Modulation in Social Anxiety Disorder

Social anxiety disorder (SAD) is characterized by social anxiety/fear, self-attention, and interoception. Functional magnetic resonance imaging studies demonstrate increased activity during symptom-sensitive tasks in regions of the default-mode network (DMN), amygdala (AMG), and salience network (SN). What is the source of this task-unspecific symptom-sensitive hyperactivity in DMN? We address this question by probing SAD resting state (rs) changes in DMN including their relation to other regions as possible source of task-unspecific hyperactivity in the same regions. Our findings show the following: (1) rs-hypoconnectivity within-DMN regions; (2) rs-hyperconnectivity between DMN and AMG/SN; (3) task-evoked hyperactivity in the abnormal rs-regions of DMN and AMG/SN during different symptom-sensitive tasks; (4) negative relationship of rest and task changes in especially anterior DMN regions as their rs-hypoconnectivity is accompanied by task-unspecific hyperactivity; (5) abnormal top-down/bottom-up modulation between anterior DMN regions and AMG during rest and task. Findings demonstrate that rs-hypoconnectivity among DMN regions is negatively related to task-unspecific hyperactivity in DMN and AMG/SN. We propose a model of "Topography of the Anxious Self" in SAD (TAS-SAD). Abnormal DMN-AMG/SN topography during rest, as trait feature of an "unstable social self", is abnormally aggravated during SAD-sensitive situations resulting in task-related hyperactivity in the same regions with an "anxious self" as state feature.

Neural mechanisms of aberrant self-referential processing in patients with generalized anxiety disorder

Massive theoretical studies in clinical psychology have implicated the self in understanding internalizing disorders (i.e., anxiety and mood disorders), in which self-related tasks were frequently used to investigate internalizing psychopathology. As one of the most frequently seen internalizing disorder in primary care, patients with generalized anxiety disorder (GAD) are characterized by inappropriate self-related processing such as negative self-referential thinking. However, relevant neural mechanisms remain unknown. In this study, participants underwent a self-related task which they were presented with several positive and negative trait words and were required to judge the extent to which these traits matched themselves when compared to their average peers. Aberrant brain activation and functional connectivity of GAD were detected during processing positive and negative traits. Compared to healthy controls (HCs), patients with GAD exhibited abnormal self-processing which manifested as lower biased self-rating scores particularly for negative traits and weaker brain activity in the left dorsomedial prefrontal cortex, inferior frontal gyrus, superior temporal sulcus (STS), and bilateral lingual gyrus when processing trait words. Abnormal functional connections between these hypoactive regions and regions associated with reward, emotion, and theory of mind were observed in subsequent psychophysiological interaction analysis. An attenuation of connectivity between the left insula and left STS was associated with greater severity of anxiety symptom in GAD patients. These findings provide insight into the abnormal neurocognitive mechanisms of biased self-related processing in GAD patients, which involves distorted self-schema accompanied by abnormal activation and functional connections of regions implicated in self-related and social cognition processing.

The brain activation of anxiety disorders with emotional stimuli-an fMRI ALE meta-analysis

Numerous studies have analyzed the state of brain activation about anxiety disorders under emotional stimuli. However, there is no meta-analysis to assess the commonality and specificity activation concerning different subtypes of anxiety. Here, we used ALE to assess this. 29 studies revealed increased bilateral amygdala, anterior cingulate gyrus, parahippocampal gyrus activation in anxiety disorders during emotional stimuli. Moreover, we observed decreased activations in the posterior cingulate, lingual gyrus, and precuneus. In sub-analysis, although different anxiety showed dissimilar activations, the principal activations were observed in limbic lobe, which might indicate the limbic circuit was the main neural reflection of anxiety symptoms.

Psychosocial stress and cannabinoid drugs affect acetylation of α-tubulin (K40) and gene expression in the prefrontal cortex of adult mice

The dynamics of neuronal microtubules are essential for brain plasticity. Vesicular transport and synaptic transmission, additionally, requires acetylation of α-tubulin, and aberrant tubulin acetylation and neurobiological deficits are associated. Prolonged exposure to a stressor or consumption of drugs of abuse, like marihuana, lead to neurological changes and psychotic disorders. Here, we studied the effect of psychosocial stress and the administration of cannabinoid receptor type 1 drugs on α-tubulin acetylation in different brain regions of mice. We found significantly decreased tubulin acetylation in the prefrontal cortex in stressed mice. The impact of cannabinoid drugs on stress-induced microtubule disturbance was investigated by administration of the cannabinoid receptor agonist WIN55,212–2 and/or antagonist rimonabant. In both, control and stressed mice, the administration of WIN55,212–2 slightly increased the tubulin acetylation in the prefrontal cortex whereas administration of rimonabant acted antagonistically indicating a cannabinoid receptor type 1 mediated effect. The analysis of gene expression in the prefrontal cortex showed a consistent expression of ApoE attributable to either psychosocial stress or administration of the cannabinoid agonist. Additionally, ApoE expression inversely correlated with acetylated tubulin levels when comparing controls and stressed mice treated with WIN55,212–2 whereas rimonabant treatment showed the opposite.

Neural effects of a short-term virtual reality self-training program to reduce social anxiety

BACKGROUND

Social anxiety disorder (SAD) is characterized by anxiety regarding social situations, avoidance of external social stimuli, and negative self-beliefs. Virtual reality self-training (VRS) at home may be a good interim modality for reducing social fears before formal treatment. This study aimed to find neurobiological evidence for the therapeutic effect of VRS.

METHODS

Fifty-two patients with SAD were randomly assigned to a VRS or waiting list (WL) group. The VRS group received an eight-session VRS program for 2 weeks, whereas the WL group received no intervention. Clinical assessments and functional magnetic resonance imaging scanning with the distress and speech evaluation tasks were repeatedly performed at baseline and after 3 weeks.

RESULTS

The post-VRS assessment showed significantly decreased anxiety and avoidance scores, distress index, and negative evaluation index for 'self', but no change in the negative evaluation index for 'other'. Patients showed significant responses to the distress task in various regions, including both sides of the prefrontal regions, occipital regions, insula, and thalamus, and to the speech evaluation task in the bilateral anterior cingulate cortex. Among these, significant neuronal changes after VRS were observed only in the right lingual gyrus and left thalamus.

CONCLUSIONS

VRS-induced improvements in the ability to pay attention to social stimuli without avoidance and even positively modulate emotional cues are based on functional changes in the visual cortices and thalamus. Based on these short-term neuronal changes, VRS can be a first intervention option for individuals with SAD who avoid society or are reluctant to receive formal treatment.

Neural correlates of attentional control in social anxiety disorder: the impact of early-life adversity and DNA methylation

BACKGROUND

Social anxiety disorder is characterized by intense fear and avoidance of social interactions and scrutiny by others. Although alterations in attentional control seem to play a central role in the psychopathology of social anxiety disorder, the neural underpinnings in prefrontal brain regions have not yet been fully clarified.

METHODS

The present study used functional MRI in participants (age 18-50 yr) with social anxiety disorder (n = 42, 31 female) and without (n = 58, 33 female). It investigated the interrelation of the effects of social anxiety disorder and early-life adversity (a main environmental risk factor of social anxiety disorder) on brain activity during an attentional control task. We applied DNA methylation analysis to determine whether epigenetic modulation in the gene encoding the glucocorticoid receptor, NR3C1, might play a mediating role in this process.

RESULTS

We identified 2 brain regions in the left and medial prefrontal cortex that exhibited an interaction effect of social anxiety disorder and early-life adversity. In participants with low levels of early-life adversity, neural activity in response to disorder-related stimuli was increased in association with social anxiety disorder. In participants with high levels of early-life adversity, neural activity was increased only in participants without social anxiety disorder. NR3C1 DNA methylation partly mediated the effect of social anxiety disorder on brain activity as a function of early-life adversity.

LIMITATIONS

The absence of behavioural correlates associated with social anxiety disorder limited functional interpretation of the results.

CONCLUSION

These findings demonstrate that the neurobiological processes that underlie social anxiety disorder might be fundamentally different depending on experiences of early-life adversity. Long-lasting effects of early-life adversity might be encoded in NR3C1 DNA methylation and entail alterations in social anxiety disorder-related activity patterns in the neural network of attentional control.

Frontoparietal and Default Mode Network Contributions to Self-Referential Processing in Social Anxiety Disorder

Social anxiety disorder (SAD) is characterized by negative self-referential processing, which triggers excessive emotional reactivity. In healthy individuals, positive self-views typically predominate and are supported by regions of the default mode network (DMN) that represent self-related information and regions of the frontoparietal control network (FPCN) that contribute to metacognitive awareness and emotion regulation. The current study used functional magnetic resonance imaging (fMRI) to examine patterns of DMN and FPCN activation during positive and negative self-referential judgments in SAD patients (N = 97) and controls (N = 34). As expected, SAD patients demonstrated a striking difference in self-beliefs compared with non-anxious healthy controls, endorsing fewer positive traits and more negative traits. However, SAD patients and controls demonstrated largely similar patterns of DMN and FPCN recruitment during self-referential judgements. No significant group differences were observed. However, equivalence testing identified numerous regions demonstrating effect sizes that were not small enough to conclude that they were practically equivalent to zero, despite the nonsignificant null hypothesis test. These regions may be key targets to investigate in future studies using larger samples.

Cognitive Neural Mechanism of Social Anxiety Disorder: A Meta-Analysis Based on fMRI Studies

Objective: The present meta-analysis aimed to explore the cognitive and neural mechanism of social anxiety disorder (SAD) from a whole-brain view, and compare the differences in brain activations under different task paradigms. Methods: We searched Web of Science Core Collection and other databases with the keywords related to social anxiety, social phobia, and functional magnetic resonance imaging (fMRI) for comparing persons with SAD to healthy controls and used the activation likelihood estimation method. Thirty-seven papers met the inclusion criteria, including 15 with emotional faces as stimuli, 8 presenting specific situations as stimuli, and 14 using other types of tasks as stimuli. Among these papers, 654 participants were in the SAD group and 594 participants were in the control group with 335 activation increase points and 115 activation decrease points. Results: Whole-brain analysis showed that compared with healthy controls, persons with SAD showed significantly lower activation of the left anterior cingulate gyrus (MNI coordinate: x = −6, y = 22, z = 38; p 0.001). Sub-group analysis based on task indicated that when performing tasks with emotional faces as stimuli, persons with SAD showed significantly lower activation of the left cerebellar slope and fusiform gyrus (MNI coordinate: x = −26, y = −68, z = −12; p 0.001), and significantly higher activation of the right supramarginal gyrus and angular gyrus, than healthy controls (MNI coordinate: x = 58, y = −52, z = 30; p 0.001). Conclusion: Individuals with social anxiety disorder show abnormal activation in the cingulate gyrus, which is responsible for the process of attention control, and task type can influence the activation pattern.

Self-other referential neural processing in social anxiety disorder and major depressive disorder

BACKGROUND

Social anxiety disorder (SAD) and major depressive disorder (MDD) are highly comorbid and share impairments in self-referential and social processing. Many naturalistic judgements activate these processes concurrently, which can be referred to as "self-other referential processing". We sought to examine its neural correlates in young people with SAD and MDD using a novel experimental task.

METHODS

Fifty six young people aged 16 to 25 with diagnoses of SAD and/or MDD (15 with SAD [M = 20.3 years, 60% female], 17 with MDD [M = 19.8 years, 53% female], 24 with comorbid SAD and MDD [M = 19.8 years, 67% female]) and 76 age and gender-matched healthy controls (HCs; M = 20.7 years, 66% female) completed a novel self-other referential processing fMRI task that involved rating how much one related to emotional faces in active conditions and judging how far apart each person's eyes were in control conditions.

RESULTS

Participants with SAD had more and those with MDD had less activity in social cognitive areas than HCs when processing social information across all conditions and emotion types. Participants with comorbid SAD-MDD exhibited a distinct pattern of neural activity to patients with single diagnoses. Across the whole sample, the activation of reward system areas (the medial orbitofrontal cortex and caudate) in response to increasing relatedness correlated positively with a dimensional measure of social anxiety.

CONCLUSIONS

Young people with SAD, MDD and comorbid SAD-MDD showed deficits in social processing, but they were not specifically related to self-other referential processing. Dimensional social anxiety symptoms were correlated with reward system activation, suggesting that such symptoms are associated with an overestimation of the hedonic value of social stimuli. These novel findings have implications for our understanding of the neural correlates of SAD and MDD, suggesting that alterations in social processing and reward functioning underlie the impairments in self and social processing that characterize both disorders.

Threat and safety reversal learning in social anxiety disorder - an fMRI study

Social anxiety disorder (SAD) has been linked to maladaptive forms of fear regulation, including flexibly distinguishing between learned threat and safety signals. Few studies have examined this in young, unmedicated SAD patients, including its neural basis. We aimed to characterize the neural, subjective, and autonomic correlates of reversal learning in patients with SAD and compare them to matched patients with major depressive disorder and to healthy control participants. All participants completed a threat-safety reversal learning task during functional magnetic resonance imaging. Successful threat-safety updating was associated with significant activation of primary regions of interest (anterior cingulate, insula and ventromedial prefrontal cortex), however, no significant differences were observed between them, consistent with subjective reports of task-evoked anxiety and affect. Contrary to expectations, we did not observe threat and safety reversal learning to be significantly impaired in young people with SAD.

Sex differences and effects of the estrous stage on hippocampal-prefrontal theta communications

Effective communication between the mammalian hippocampus and neocortex is essential to certain cognitive-behavioral tasks critical to survival in a changing environment. Notably, functional synchrony between local field potentials (LFPs) of the ventral hippocampus (vHPC) and the medial prefrontal cortex (mPFC) within the theta band (4-12 Hz) underlies innate avoidance behavior during approach-avoidance conflict tasks in male rodents. However, the physiology of vHPC-mPFC communications in females remains unestablished. Furthermore, little is known about how mPFC subdivisions functionally interact in the theta band with hippocampal subdivisions in both sexes in the absence of task demand. Given the established roles of biological sex and gonadal hormone status on innate avoidance behaviors and neuronal excitability, here, we characterize the effects of biological sex and female estrous stage on hippocampal-prefrontal (HPC-mPFC) theta signaling in freely moving female and male rats. LFPs from vHPC, dorsal hippocampus (dHPC), mPFC-prelimbic (PrL), and mPFC-infralimbic (IL) were simultaneously recorded during spontaneous exploration of a familiar arena. Data suggest that theta phase and power in vHPC preferentially synchronize with PrL; conversely, dHPC and IL preferentially synchronize. Males displayed greater vHPC-PrL theta synchrony than females, despite similar regional frequency band power and inter-regional coherence. Additionally, several significant estrous-linked changes in HPC-mPFC theta dynamics were observed. These findings support the hypothesis that HPC-mPFC theta signaling is sensitive to both biological sex and female estrous stage. These findings establish novel research avenues concerning sex as a biological variable and effects of gonadal hormone status on HPC-mPFC network activity as it pertains to threat evaluation biomarkers.

Abnormal dynamic functional connectivity density in patients with generalized anxiety disorder

BACKGROUND

Numerous studies have revealed the abnormal static functional connectivity (FC) among different brain regions in patients with generalized anxiety disorder (GAD). However, little is known about the dynamic changes of FC in patients with GAD.

METHODS

This study investigated the whole-brain dynamic changes of FC in patients with GAD by combining global FC density (FCD) and sliding window correlation analyses. The standard deviation of dynamic FCD (dFCD) was calculated to evaluate its temporal variability along time. Support vector regression was then employed to predict the symptom severity of patients based on abnormal dynamic connectivity patterns.

RESULTS

The abnormal dFCD variability between 81 GAD patients and 80 healthy controls showed that the patients had higher dFCD variability in the bilateral dorsomedial prefrontal cortex (dmPFC) and left hippocampus while lower dFCD variability in the right postcentral gyrus. The abnormal dFCD variability of the left dmPFC is an important feature for anxiety prediction.

LIMITATIONS

The selection of sliding window length remains controversial, and most of our patients have been treated with medications. Future studies are expected to rule out the potential confounding effects from applying different parameters of the sliding window and recruiting large samples of medication-free patients.

CONCLUSION

The altered patterns of time-varying brain connectivity in the frontolimbic and sensorimotor areas may reflect abnormal dynamic neural communication between these regions and other regions of the brain, which may deepen our understanding of the disease.

Not intended, still embarrassed: Social anxiety is related to increased levels of embarrassment in response to unintentional social norm violations

Background:

Social anxiety disorder (SAD) is associated with altered social norm (SN) processing: SAD-patients rate stories on SN violations as more inappropriate and more embarrassing than healthy participants, with the most prominent effect for stories on unintentional SN violations (i.e. committing a blunder). Until now it’s unknown how levels of social anxiety (SA) are related to ratings of SN violations in the general population, in which SA-symptoms are present at a continuum. More insight in this relationship could improve our understanding of the symptom profile of SAD. Therefore, we investigated the relation between ratings of SN violations and SA-levels in the general population.

Methods:

Adults and adolescents (n = 87) performed the revised Social Norm Processing Task (SNPT-R) and completed self-report questionnaires on social anxiety. Repeated-measures ANCOVAs were used to investigate the effect of SA on the ratings of inappropriateness and embarrassment.

Results:

As hypothesized, participants with higher SA-levels rated SN violations as more inappropriate and more embarrassing. Whereas participants with low-to-intermediate SA-levels rated unintentional SN violations as less embarrassing than intentional SN violations, participants with high SA-levels (z-score SA ≥ 1.6) rated unintentional SN violations as equally embarrassing as intentional SN violations.

Conclusion:

These findings indicate that increased embarrassment for unintentional SN violations is an important characteristic of social anxiety. These high levels of embarrassment are likely related to the debilitating concern of socially-anxious people that their skills and behavior do not meet expectations of others, and to their fear of blundering. This concern might be an important target for future therapeutic interventions.

Overanxious and underslept

Are you feeling anxious? Did you sleep poorly last night? Sleep disruption is a recognized feature of all anxiety disorders. Here, we investigate the basic brain mechanisms underlying the anxiogenic impact of sleep loss. Additionally, we explore whether subtle, societally common reductions in sleep trigger elevated next-day anxiety. Finally, we examine what it is about sleep, physiologically, that provides such an overnight anxiety-reduction benefit. We demonstrate that the anxiogenic impact of sleep loss is linked to impaired medial prefrontal cortex activity and associated connectivity with extended limbic regions. In contrast, non-rapid eye movement (NREM) slow-wave oscillations offer an ameliorating, anxiolytic benefit on these brain networks following sleep. Of societal relevance, we establish that even modest night-to-night reductions in sleep across the population predict consequential day-to-day increases in anxiety. These findings help contribute to an emerging framework explaining the intimate link between sleep and anxiety and further highlight the prospect of non-rapid eye movement sleep as a therapeutic target for meaningfully reducing anxiety.

Neural responses to social evaluation: The role of fear of positive and negative evaluation

One of the core features of social anxiety disorder (SAD) is the persistent fear of being evaluated. Fear of evaluation includes fear of negative evaluation (FNE) and fear of positive evaluation (FPE). Few studies have examined the relationship between self-reported FNE and FPE and neural responses to simulated negative and positive social evaluation. In the current study, 56 participants, 35 with SAD and 21 healthy controls, completed questionnaires to assess dimensions of social anxiety including FNE and FPE, as well as symptoms of anxiety and depression. Participants also completed a social evaluation task, which involved viewing people delivering criticism and praise, and a control task, which involved counting asterisks, during functional magnetic resonance imaging. Although whole-brain analyses did not reveal significant associations between self-reported constructs and neural responses to social evaluation, region of interest analyses for the sample as a whole revealed that both FNE and social anxiety symptoms were associated with greater neural responses to both criticism and praise in emotion-processing brain regions, including the amygdala and anterior insula. There were no significant associations between FPE or depressive symptoms and neural responses to criticism or praise for the sample as a whole. Future research should examine the relationship between FNE, FPE, and neural responses to self-referent social evaluation in an unselected sample to assess a full range of fear of evaluation.

Altered Neurobiological Processing of Unintentional Social Norm Violations: A Multiplex, Multigenerational Functional Magnetic Resonance Imaging Study on Social Anxiety Endophenotypes

BACKGROUND

Patients with social anxiety disorder (SAD) fear negative evaluation in social situations. Specifically, previous work indicated that social anxiety is associated with increased medial prefrontal cortex activation in response to unintentional social norm (SN) transgressions, accompanied by increased embarrassment ratings for such SN violations. Here, we used data from the multiplex, multigenerational LFLSAD (Leiden Family Lab study on Social Anxiety Disorder), which involved two generations of families genetically enriched for SAD, and investigated whether these neurobiological and behavioral correlates of unintentional SN processing are SAD endophenotypes. Of four endophenotype criteria, we examined two: first, the cosegregation of these characteristics with social anxiety (SA) within families of SAD probands (criterion 4), and second, the heritability of the candidate endophenotypes (criterion 3).

METHODS

Participants (n = 110, age range 9.0-61.5 years, eight families) performed the revised Social Norm Processing Task; functional magnetic resonance imaging data and behavioral ratings related to this paradigm were used to examine whether brain activation in response to processing unintentional SN violations and ratings of embarrassment were associated with SA levels. Next, heritability of these measurements was estimated.

RESULTS

As expected, voxelwise functional magnetic resonance imaging analyses revealed positive associations between SA levels and brain activation in the medial prefrontal cortex and medial temporal gyrus, superior temporal gyrus, and superior temporal sulcus, and these brain activation levels displayed moderate to moderately high heritability. Furthermore, although SA levels correlated positively with behavioral ratings of embarrassment for SN transgressions, these behavioral characteristics were not heritable.

CONCLUSIONS

These results show, for the first time, that brain responses in the medial prefrontal cortex and medial temporal gyrus, superior temporal gyrus, and superior temporal sulcus, related to processing unintentional SN violations, provide a neurobiological candidate endophenotype of SAD.

Neural Correlates of Self-referential Processing and Their Clinical Implications in Social Anxiety Disorder

Social anxiety disorder (SAD) is associated with aberrant self-referential processing (SRP) such as increased self-focused attention. Aberrant SRP is one of the core features of SAD and is also related to therapeutic interventions. Understanding of the underlying neural correlates of SRP in SAD is important for identifying specific brain regions as treatment targets. We reviewed functional magnetic resonance imaging (fMRI) studies to clarify the neural correlates of SRP and their clinical implications for SAD. Task-based and resting fMRI studies have reported the cortical midline structures including the default mode network, theory of mind-related regions of the temporo-parietal junction and temporal pole, and the insula as significant neural correlates of aberrant SRP in SAD patients. Also, these neural correlates are related to clinical improvement on pharmacological and cognitive-behavioral treatments. Furthermore, these could be candidates for the development of novel SAD treatments. This review supports that neural correlates of SAD may be significant biomarkers for future pathophysiology based treatment.

A mind full of self: Self-referential processing as a mechanism underlying the therapeutic effects of mindfulness training on internalizing disorders

The aim of the current review is to advance the hypothesis that change in self-referential processing is a key but under-examined mechanism through which mindfulness training confers its therapeutic benefits for individuals with internalizing disorders. Consequently, we integrated neuroscientific studies on aberrant self-referential processing in internalizing disorders with contemplative science scholarship examining the effects of mindfulness training on the self-referential system. Reviewing these literatures yielded four major conclusions: (1) internalizing disorders can be characterized by excessive self-referential processing and emotion dysregulation; (2) mindfulness training has moderate effects on reducing internalizing symptoms; (3) mindfulness training promotes the shifting from narrative self-focus to present-centered experiential awareness; (4) such mindfulness-induced changes in self-reference is accompanied by reduced activation in overactive self-referential brain regions that have been implicated in internalizing disorders. Clinical and research implications related to delineating the role of self-referential processing in producing the therapeutic effects of mindfulness training are discussed.

Effects of repeated long-term psychosocial stress and acute cannabinoid exposure on mouse corticostriatal circuitries: Implications for neuropsychiatric disorders

Introduction

Vulnerability to psychiatric manifestations is achieved by the influence of genetic and environment including stress and cannabis consumption. Here, we used a psychosocial stress model based on resident‐intruder confrontations to study the brain corticostriatal‐function, since deregulation of corticostriatal circuitries has been reported in many psychiatric disorders. CB₁ receptors are widely expressed in the central nervous system and particularly, in both cortex and striatum brain structures.

Aims and methods

The investigation presented here is addressed to assess the impact of repeated stress following acute cannabinoid exposure on behavior and corticostriatal brain physiology by assessing mice behavior, the concentration of endocannabinoid and endocannabinoid‐like molecules and changes in the transcriptome.

Results

Stressed animals urinated frequently; showed exacerbated scratching activity, lower striatal N‐arachidonylethanolamine (AEA) levels and higher cortical expression of cholinergic receptor nicotinic alpha 6. The cannabinoid agonist WIN55212.2 diminished locomotor activity while the inverse agonist increased the distance travelled in the center of the open field. Upon CB₁ activation, N‐oleoylethanolamide and N‐palmitoylethanolamide, two AEA congeners that do not interact directly with cannabinoid receptors, were enhanced in the striatum. The co‐administration with both cannabinoids induced an up‐regulation of striatal FK506 binding protein 5. The inverse agonist in controls reversed the effects of WIN55212.2 on motor activity. When Rimonabant was injected under stress, the cortical levels of 2‐arachidonoylglycerol were maximum. The agonist and the antagonist influenced the cortical expression of cholinergic receptor nicotinic alpha 6 and serotonin transporter neurotransmitter type 4 in opposite directions, while their co‐administration tended to produce a null effect under stress.

Conclusions

The endocannabinoid system had a direct effect on serotoninergic neurotransmission and glucocorticoid signaling. Cholinergic receptor nicotinic alpha‐6 was shown to be deregulated in response to stress and following synthetic cannabinoid drugs thus could confer vulnerability to cannabis addiction and psychosis. Targeting the receptors of endocannabinoids and endocannabinoid‐like mediators might be a valuable option for treating stress‐related neuropsychiatric symptoms.

Reduced optimism and a heightened neural response to everyday worries are specific to generalized anxiety disorder, and not seen in social anxiety

BACKGROUND

Generalized anxiety disorder (GAD) and social anxiety disorder (SAD) are co-morbid and associated with similar neural disruptions during emotion regulation. In contrast, the lack of optimism examined here may be specific to GAD and could prove an important biomarker for that disorder.

METHOD

Unmedicated individuals with GAD (n = 18) and age-, intelligence quotient- and gender-matched SAD (n = 18) and healthy (n = 18) comparison individuals were scanned while contemplating likelihoods of high- and low-impact negative (e.g. heart attack; heartburn) or positive (e.g. winning lottery; hug) events occurring to themselves in the future.

RESULTS

As expected, healthy subjects showed significant optimistic bias (OB); they considered themselves significantly less likely to experience future negative but significantly more likely to experience future positive events relative to others (p < 0.001). This was also seen in SAD, albeit at trend level for positive events (p < 0.001 and p < 0.10, respectively). However, GAD patients showed no OB for positive events (t 17 = 0.82, n.s.) and showed significantly reduced neural modulation relative to the two other groups of regions including the medial prefrontal cortex (mPFC) and caudate to these events (p < 0.001 for all). The GAD group further differed from the other groups by showing increased neural responses to low-impact events in regions including the rostral mPFC (p < 0.05 for both).

CONCLUSIONS

The neural dysfunction identified here may represent a unique feature associated with reduced optimism and increased worry about everyday events in GAD. Consistent with this possibility, patients with SAD did not show such dysfunction. Future studies should consider if this dysfunction represents a biomarker for GAD.

Task-dependent modulation of amygdala connectivity in social anxiety disorder

Increased amygdala activation is consistently found in patients suffering from social anxiety disorder (SAD), a psychiatric condition characterized by an intense fear of social situations and scrutiny. Disruptions in the amygdalar-frontal network in SAD may explain the inability of frontal regions to appropriately down-regulate amygdalar hyper-activation. In this study, we measured 15 SAD patients and 15 healthy controls during an affective counting Stroop task with emotional faces to assess the interaction of affective stimuli with a cognitive task in SAD, as well as to investigate the causal interactions between the amygdala and the medial orbitofrontal cortex (OFC) using dynamic causal modeling (DCM). Here we show for the first time that differences in OFC-amygdala effective connectivity between SAD patients and healthy controls are influenced by cognitive load during task processing. In SAD patients relative to controls dysfunctional amygdala regulation was observed during passive viewing of harsh faces This could be linked to ongoing self-initiated cognitive processes (such as rumination and anticipation of negative events) that hinder successful amygdala regulation. However, between-group differences diminished during cognitive processing, suggesting that attentional load interfered with emotional processing in both patients and controls.

Neural responses to social threat and predictors of cognitive behavioral therapy and acceptance and commitment therapy in social anxiety disorder

Previous research has often highlighted hyperactivity in emotion regions to simple, static social threat cues in social anxiety disorder (SAD). Investigation of the neurobiology of SAD using more naturalistic paradigms can further reveal underlying mechanisms and how these relate to clinical outcomes. We used fMRI to investigate responses to novel dynamic rejection stimuli in individuals with SAD (N=70) and healthy controls (HC; N=17), and whether these responses predicted treatment outcomes following cognitive behavioral therapy (CBT) or acceptance and commitment therapy (ACT). Both HC and SAD groups reported greater distress to rejection compared to neutral social stimuli. At the neural level, HCs exhibited greater activations in social pain/rejection regions, including dorsal anterior cingulate cortex and anterior insula, to rejection stimuli. The SAD group evidenced a different pattern, with no differences in these rejection regions and relatively greater activations in the amygdala and other regions to neutral stimuli. Greater responses in anterior cingulate cortex and the amygdala to rejection vs. neutral stimuli predicted better CBT outcomes. In contrast, enhanced activity in sensory-focused posterior insula predicted ACT responses.

Learning from other people's fear: amygdala-based social reference learning in social anxiety disorder

BACKGROUND

Social anxiety disorder involves fear of social objects or situations. Social referencing may play an important role in the acquisition of this fear and could be a key determinant in future biomarkers and treatment pathways. However, the neural underpinnings mediating such learning in social anxiety are unknown. Using event-related functional magnetic resonance imaging, we examined social reference learning in social anxiety disorder. Specifically, would patients with the disorder show increased amygdala activity during social reference learning, and further, following social reference learning, show particularly increased response to objects associated with other people's negative reactions?

METHOD

A total of 32 unmedicated patients with social anxiety disorder and 22 age-, intelligence quotient- and gender-matched healthy individuals responded to objects that had become associated with others' fearful, angry, happy or neutral reactions.

RESULTS

During the social reference learning phase, a significant group × social context interaction revealed that, relative to the comparison group, the social anxiety group showed a significantly greater response in the amygdala, as well as rostral, dorsomedial and lateral frontal and parietal cortices during the social, relative to non-social, referencing trials. In addition, during the object test phase, relative to the comparison group, the social anxiety group showed increased bilateral amygdala activation to objects associated with others' fearful reactions, and a trend towards decreased amygdala activation to objects associated with others' happy and neutral reactions.

CONCLUSIONS

These results suggest perturbed observational learning in social anxiety disorder. In addition, they further implicate the amygdala and dorsomedial prefrontal cortex in the disorder, and underscore their importance in future biomarker developments.

The aetiology and maintenance of social anxiety disorder: A synthesis of complimentary theoretical models and formulation of a new integrated model

BACKGROUND

Within maintenance models of social anxiety disorder (SAD), a number of cognitive and behavioural factors that drive the persistence of SAD have been proposed. However, these maintenance models do not address how SAD develops, or the origins of the proposed maintaining factors. There are also models of the development of SAD that have been proposed independently from maintenance models. These models highlight multiple factors that contribute risk to the onset of SAD, but do not address how these aetiological factors may lead to the development of the maintaining factors associated with SAD.

METHODS

A systematic review of the literature was conducted to identify aetiological and maintenance models of SAD. We then united key factors identified in these models and formulated an integrated aetiological and maintenance (IAM) model of SAD. A systematic review of the literature was then conducted on the components of the IAM model.

RESULTS

A number of aetiological and maintaining factors were identified in models of SAD. These factors could be drawn together into the IAM model. On balance, there is empirical evidence for the association of each of the factors in the IAM model with social anxiety or SAD, providing preliminary support for the model.

LIMITATIONS

There are relationships between components of the IAM model that require empirical attention. Future research will need to continue to test the IAM model.

CONCLUSIONS

The IAM model provides a framework for future investigations into the development and persistence of SAD.

Neural activity during self-referential working memory and the underlying role of the amygdala in social anxiety disorder

Self-referential processing, theory of mind, and working memory are distorted in social anxiety disorder (SAD). This study aimed to investigate characteristics of altered self-referential working memory processing and resting-state functional connectivity in patients with SAD. Twenty patients and 20 healthy controls underwent functional magnetic resonance imaging at resting-state and while performing a working memory task containing faces with self-referential positive or negative comments and three memory phases (encoding, maintenance, and retrieval). Task-related results were compared between groups and tested for correlations. Resting-state connectivity between amygdala subregions and regions showing a task-related difference was also compared between groups. Patients compared to controls showed augmented memory for the negative comments, hyperactivation of the dorsomedial prefrontal cortex and temporo-parietal junction during encoding, and hypoactivation of the dorsolateral prefrontal cortex and insula during retrieval. At resting-state, increased connectivity of amygdala subregions with multiple task-related regions was found in patients. These findings suggest that the encoding process in SAD is accompanied by altered involvement of self-referential processing and theory of mind, whereas the retrieval process reflects impaired cognitive control. These memory-related processing may be affected by predisposing resting-state hyperconnectivity with the amygdala, and may underlie a hypersensitivity to negative comments and post-event reflection in SAD.

Abnormal brain activation and connectivity to standardized disorder-related visual scenes in social anxiety disorder

Our understanding of altered emotional processing in social anxiety disorder (SAD) is hampered by a heterogeneity of findings, which is probably due to the vastly different methods and materials used so far. This is why the present functional magnetic resonance imaging (fMRI) study investigated immediate disorder-related threat processing in 30 SAD patients and 30 healthy controls (HC) with a novel, standardized set of highly ecologically valid, disorder-related complex visual scenes. SAD patients rated disorder-related as compared with neutral scenes as more unpleasant, arousing and anxiety-inducing than HC. On the neural level, disorder-related as compared with neutral scenes evoked differential responses in SAD patients in a widespread emotion processing network including (para-)limbic structures (e.g. amygdala, insula, thalamus, globus pallidus) and cortical regions (e.g. dorsomedial prefrontal cortex (dmPFC), posterior cingulate cortex (PCC), and precuneus). Functional connectivity analysis yielded an altered interplay between PCC/precuneus and paralimbic (insula) as well as cortical regions (dmPFC, precuneus) in SAD patients, which emphasizes a central role for PCC/precuneus in disorder-related scene processing. Hyperconnectivity of globus pallidus with amygdala, anterior cingulate cortex (ACC) and medial prefrontal cortex (mPFC) additionally underlines the relevance of this region in socially anxious threat processing. Our findings stress the importance of specific disorder-related stimuli for the investigation of altered emotion processing in SAD. Disorder-related threat processing in SAD reveals anomalies at multiple stages of emotion processing which may be linked to increased anxiety and to dysfunctionally elevated levels of self-referential processing reported in previous studies.

Fear of negative evaluation is associated with altered brain function in nonclinical subjects

Social anxiety disorder (SAD), which involves excessive anxiety and fear of negative evaluation, is accompanied by abnormalities in brain function. While social anxiety appears to be represented on a spectrum ranging from nonclinical behavior to clinical manifestation, neural alteration in nonclinical populations remains unclear. This study examined the relationship between psychological measures of social anxiety, mainly using the Fear of Negative Evaluation Scale (FNES), and brain function (functional connectivity, degree centrality, and regional betweenness centrality). Results showed that FNES scores and functional connectivity of the parahippocampal gyrus and orbitofrontal cortex and the betweenness centrality of the right parietal cortex were negatively correlated. These regions are altered in SAD patients, and each is associated with social cognition and emotional processing. The results supported the perspective that social anxiety occurs on a spectrum and indicated that the FNES is a useful means of detecting neural alterations that may relate to the social anxiety spectrum. In addition, the findings indicated that graph analysis was useful in investigating the neural underpinnings of SAD in addition to other psychiatric symptoms.

Neural pathways of embarrassment and their modulation by social anxiety

While being in the center of attention and exposed to other's evaluations humans are prone to experience embarrassment. To characterize the neural underpinnings of such aversive moments, we induced genuine experiences of embarrassment during person-group interactions in a functional neuroimaging study. Using a mock-up scenario with three confederates, we examined how the presence of an audience affected physiological and neural responses and the reported emotional experiences of failures and achievements. The results indicated that publicity induced activations in mentalizing areas and failures led to activations in arousal processing systems. Mentalizing activity as well as attention towards the audience were increased in socially anxious participants. The converging integration of information from mentalizing areas and arousal processing systems within the ventral anterior insula and amygdala forms the neural pathways of embarrassment. Targeting these neural markers of embarrassment in the (para-)limbic system provides new perspectives for developing treatment strategies for social anxiety disorders.

Neural correlates of self-focused attention in social anxiety

Socially anxious individuals tend to shift their attention away from external socially threatening cues and instead become highly self-focused. Such heightened self-focused attention has been suggested to be involved in the development and maintenance of social anxiety disorder. This study used functional magnetic resonance imaging to investigate the neural correlates of self-focused attention in 16 high socially anxious (HSA) and 16 low socially anxious (LSA) individuals. Participants were instructed to focus their attention either inwardly or outwardly during a simulated social situation. Results indicate hyperactivation of medial prefrontal cortex (mPFC), temporo-parietal junction (TPJ) and temporal pole during inward vs outward attention in HSA compared with LSA participants. Furthermore, activation of mPFC, right anterior insula, TPJ and posterior cingulate cortex was positively correlated with the trait of self-focused attention in HSA subjects. Results highlight the prominent role of the mPFC and other cortical structures in abnormal self-focused attention in social anxiety. Finally, findings for the insula suggest increased processing of bodily states that is related to the amount of habitual self-focused attention in social anxiety.

Neural circuits in anxiety and stress disorders: a focused review

Anxiety and stress disorders are among the most prevalent neuropsychiatric disorders. In recent years, multiple studies have examined brain regions and networks involved in anxiety symptomatology in an effort to better understand the mechanisms involved and to develop more effective treatments. However, much remains unknown regarding the specific abnormalities and interactions between networks of regions underlying anxiety disorder presentations. We examined recent neuroimaging literature that aims to identify neural mechanisms underlying anxiety, searching for patterns of neural dysfunction that might be specific to different anxiety disorder categories. Across different anxiety and stress disorders, patterns of hyperactivation in emotion-generating regions and hypoactivation in prefrontal/regulatory regions are common in the literature. Interestingly, evidence of differential patterns is also emerging, such that within a spectrum of disorders ranging from more fear-based to more anxiety-based, greater involvement of emotion-generating regions is reported in panic disorder and specific phobia, and greater involvement of prefrontal regions is reported in generalized anxiety disorder and posttraumatic stress disorder. We summarize the pertinent literature and suggest areas for continued investigation.

Impaired self-awareness in human addiction: deficient attribution of personal relevance

Compromised self-awareness of illness-related deficits and behaviors in psychopathology (e.g., schizophrenia) has been associated with deficient functioning of cortical midline regions including the ventromedial prefrontal cortex (vmPFC), implicated in personal relevance. Here, we review and critically analyze recent evidence to suggest that vmPFC abnormalities could similarly underlie deficient tagging of personal relevance in drug addiction, evidenced by a constellation of behaviors encompassing drug-biased attention, negative outcome insensitivity, self-report/behavior dissociation, and social inappropriateness. This novel framework might clarify, for example, why drug-addicted individuals often ruin long-standing relationships or forego important job opportunities while continuing to engage in uncontrolled drug-taking. Therapeutic interventions targeting personal relevance and associated vmPFC functioning could enhance self-awareness and facilitate more adaptive behavior in this chronically relapsing psychopathology.

Of 'disgrace' and 'pain'--corticolimbic interaction patterns for disorder-relevant and emotional words in social phobia

Limbic hyperactivation and an impaired functional interplay between the amygdala and the prefrontal cortex are discussed to go along with, or even cause, pathological anxiety. Within the multi-faceted group of anxiety disorders, the highly prevalent social phobia (SP) is characterized by excessive fear of being negatively evaluated. Although there is widespread evidence for amygdala hypersensitivity to emotional faces in SP, verbal material has rarely been used in imaging studies, in particular with an eye on disorder-specificity. Using functional magnetic resonance imaging (fMRI) and a block design consisting of (1) overall negative, (2) social-phobia related, (3) positive, and (4) neutral words, we studied 25 female patients with social phobia and 25 healthy female control subjects (HC). Results demonstrated amygdala hyperactivation to disorder-relevant but not to generally negative words in SP patients, with a positive correlation to symptom severity. A functional connectivity analysis revealed a weaker coupling between the amygdala and the left middle frontal gyrus in patients. Symptom severity was negatively related to connectivity strength between the amygdala and the ventromedial prefrontal and orbitofrontal cortex (Brodmann Area 10 and 11). The findings clearly support the view of a hypersensitive threat-detection system, combined with disorder-related alterations in amygdala-prefrontal cortex connectivity in pathological anxiety.

The temporal unfolding of face processing in social anxiety disorder--a MEG study

The current study is the first to use magnetoencephalography (MEG) to examine how individuals with social anxiety disorder (SAD) process emotional facial expressions (EFEs). We expected that, compared to healthy controls (HCs), participants with SAD will show an early (<200 ms post-stimulus) over-activation in the insula and the fusiform gyrus (FG, associated with the N170/M170 component), and later (>200 ms post-stimulus) over-activation in the dorsolateral prefrontal cortex (DLPFC). Individuals with SAD (n = 12) and healthy controls (HCs, n = 12) were presented with photographs of facial displays during MEG recording. As compared to the HC group, the SAD group showed a reduced M170 (right FG under-activation around 130–200 ms); early reduced activation in the right insula, and lower insular sensitivity to the type of EFE displayed. In addition, the SAD group showed a late over-activation in the right DLPFC. This unique EFE processing pattern in SAD suggests an early under-activation of cortical areas, possibly related to reduced emphasis on high spatial frequency information and greater early emphasis on low spatial frequency information. The late DLPFC over-activation in the SAD group may correlate to failures of cognitive control in this disorder. The importance of a temporal perspective for the understanding of facial processing in psychopathology is underlined.

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This study is the first to use MEG to study social anxiety disorder (SAD).

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SADs and controls viewed emotional facial expressions during MEG.

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Compared to controls, SADs showed reduced M170 (early fusiform gyrus activity).

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SADs presented a late over-activation in the right dorsolateral prefrontal cortex.

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The late frontal over-activity may correlate to failures of cognitive control in SAD.

Impact of cognitive-behavioral therapy for social anxiety disorder on the neural bases of emotional reactivity to and regulation of social evaluation

We examined whether Cognitive-Behavioral Therapy (CBT) for social anxiety disorder (SAD) would modify self-reported negative emotion and functional magnetic resonance imaging brain responses when reacting to and reappraising social evaluation, and tested whether changes would predict treatment outcome in 59 patients with SAD who completed CBT or waitlist groups. For reactivity, compared to waitlist, CBT resulted in (a) increased brain responses in right superior frontal gyrus (SFG), inferior parietal lobule (IPL), and middle occipital gyrus (MOG) when reacting to social praise, and (b) increases in right SFG and IPL and decreases in left posterior superior temporal gyrus (pSTG) when reacting to social criticism. For reappraisal, compared to waitlist, CBT resulted in greater (c) reductions in self-reported negative emotion, and (d) increases in brain responses in right SFG and MOG, and decreases in left pSTG. A linear regression found that after controlling for CBT-induced changes in reactivity and reappraisal negative emotion ratings and brain changes in reactivity to praise and criticism, reappraisal of criticism brain response changes predicted 24% of the unique variance in CBT-related reductions in social anxiety. Thus, one mechanism underlying CBT for SAD may be changes in reappraisal-related brain responses to social criticism.

CLINICALTRIALSGOV IDENTIFIER

NCT00380731. http://www.clinicaltrials.gov/ct2/show/NCT00380731?term=social+anxiety+cognitive+behavioral+therapy+Stanford&rank=1.

Neural correlates of anticipation and processing of performance feedback in social anxiety

Fear of negative evaluation, such as negative social performance feedback, is the core symptom of social anxiety. The present study investigated the neural correlates of anticipation and perception of social performance feedback in social anxiety. High (HSA) and low (LSA) socially anxious individuals were asked to give a speech on a personally relevant topic and received standardized but appropriate expert performance feedback in a succeeding experimental session in which neural activity was measured during anticipation and presentation of negative and positive performance feedback concerning the speech performance, or a neutral feedback-unrelated control condition. HSA compared to LSA subjects reported greater anxiety during anticipation of negative feedback. Functional magnetic resonance imaging results showed deactivation of medial prefrontal brain areas during anticipation of negative feedback relative to the control and the positive condition, and medial prefrontal and insular hyperactivation during presentation of negative as well as positive feedback in HSA compared to LSA subjects. The results indicate distinct processes underlying feedback processing during anticipation and presentation of feedback in HSA as compared to LSA individuals. In line with the role of the medial prefrontal cortex in self-referential information processing and the insula in interoception, social anxiety seems to be associated with lower self-monitoring during feedback anticipation, and an increased self-focus and interoception during feedback presentation, regardless of feedback valence.

Area-dependent time courses of brain activation during video-induced symptom provocation in social anxiety disorder

BACKGROUND

Previous functional imaging studies using symptom provocation in patients with social anxiety disorder (SAD) reported inconsistent findings, which might be at least partially related to different time-dependent activation profiles in different brain areas. In the present functional magnetic resonance imaging study, we used a novel video-based symptom provocation design in order to investigate the magnitude and time course of activation in different brain areas in 20 SAD patients and 20 healthy controls.

RESULTS

The disorder-related videos induced increased anxiety in patients with SAD as compared to healthy controls. Analyses of brain activation to disorder-related versus neutral video clips revealed amygdala activation during the first but not during the second half of the clips in patients as compared to controls. In contrast, the activation in the insula showed a reversed pattern with increased activation during the second but not during the first half of the video clips. Furthermore, a cluster in the anterior dorsal anterior cingulate cortex showed a sustained response for the entire duration of the videos.

CONCLUSIONS

The present findings suggest that different regions of the fear network show differential temporal response patterns during video-induced symptom provocation in SAD. While the amygdala is involved during initial threat processing, the insula seems to be more involved during subsequent anxiety responses. In accordance with cognitive models of SAD, a medial prefrontal region engaged in emotional-cognitive interactions is generally hyperactivated.

Functional effects of chronic paroxetine versus placebo on the fear, stress and anxiety brain circuit in Social Anxiety Disorder: initial validation of an imaging protocol for drug discovery

Recent studies suggest that pharmacologic effects of anxiolytic agents can be mapped as functional changes in the fear, stress and anxiety brain circuit. In this work we investigated the effects of a standard treatment, paroxetine (20mg/day), in subjects with Social Anxiety Disorder (SAD) versus placebo using different fMRI paradigms. The fMRI sessions, performed before and after the treatment, consisted of a public exposition of recorded performance task (PERPT), an emotional face processing task (EFPT) and a 6-min resting state followed by an off-scanner public speaking test. Paroxetine significantly improved the clinical conditions of SAD patients (n=17) vs. placebo (n=16) as measured with Clinical Global Inventory - Improvement (CGI-I) while no change was seen when using Liebowitz Social Anxiety Scale, as expected given the small size of the study population. Paroxetine reduced the activation of insula, thalamus and subgenual/anterior cingulate cortex (ACC) in PERPT. Resting-state fMRI assessment using Independent Component Analysis indicated that paroxetine reduced functional connectivity in insula, thalamus and ACC when compared with placebo. Both paradigms showed significant correlation with CGI-I in rostral prefrontal cortex. Conversely, paroxetine compared to placebo produced activation of right amygdala and bilateral insula and no effects in ACC when tested with EFPT. No treatment effects on distress scores were observed in the off-scanner Public Speaking Test. Overall this study supports the use of fMRI as sensitive approach to explore the neurobiological substrate of the effects of pharmacologic treatments and, in particular, of resting state fMRI given its simplicity and task independence.

Contextual modulation of medial prefrontal cortex to neutral faces in anxious adolescents

BACKGROUND

Although interpretation biases are well documented among youth with anxiety disorders, understanding of their neural correlates is limited. In particular, there has been little study of how anxious youth neurobiologically represent changing contextual cues that may trigger anxiety. This study examined neural responses during a task in which participants viewed neutral faces paired with experimentally manipulated contextual stimuli.

METHODS

Participants (16 youth with a primary anxiety disorder diagnosis and 15 age- and gender-matched controls) passively viewed neutral faces that were paired with either neutral descriptive vignettes or with vignettes that were potentially anxiety provoking (for example, those that involved performance/social evaluation).

RESULTS

The two groups were differentiated by their medial prefrontal cortex (mPFC) responses, such that context modulated mPFC activation in anxious youth while non-anxious youth demonstrated no such differentiation. Counter to expectations, the performance/evaluation frames were not associated with amygdala reactivity for either group.

CONCLUSIONS

The present investigation is among the first to identify how context modulates mPFC responding to neutral stimuli among anxious youth. It takes an important step toward understanding the neurobiological correlates underlying interpretation biases of neutral stimuli in this population.

Brain activation during anticipatory anxiety in social anxiety disorder

Exaggerated anticipatory anxiety during expectation of performance-related situations is an important feature of the psychopathology of social anxiety disorder (SAD). The neural basis of anticipatory anxiety in SAD has not been investigated in controlled studies. The current study used functional magnetic resonance imaging (fMRI) to investigate the neural correlates during the anticipation of public and evaluated speaking vs a control condition in 17 SAD patients and 17 healthy control subjects. FMRI results show increased activation of the insula and decreased activation of the ventral striatum in SAD patients, compared to control subjects during anticipation of a speech vs the control condition. In addition, an activation of the amygdala in SAD patients during the first half of the anticipation phase in the speech condition was observed. Finally, the amount of anticipatory anxiety of SAD patients was negatively correlated to the activation of the ventral striatum. This suggests an association between incentive function, motivation and anticipatory anxiety when SAD patients expect a performance situation.

On the role of the ventromedial prefrontal cortex in self-processing: the valuation hypothesis

With the development of functional neuroimaging, important progress has been made in identifying the brain regions involved in self-related processing. One of the most consistent findings has been that the ventromedial prefrontal cortex (vMPFC) is activated when people contemplate various aspects of themselves and their life, such their traits, experiences, preferences, abilities, and goals. Recent evidence suggests that this region may not support the act of self-reflection per se, but its precise function in self-processing remains unclear. In this article, I examine the hypothesis that the vMPFC may contribute to assign personal value or significance to self-related contents: stimuli and mental representations that refer or relate to the self tend to be assigned unique value or significance, and the function of the vMPFC may precisely be to evaluate or represent such significance. Although relatively few studies to date have directly tested this hypothesis, several lines of evidence converge to suggest that vMPFC activity during self-processing depends on the personal significance of self-related contents. First, increasing psychological distance from self-representations leads to decreased activation in the vMPFC. Second, the magnitude of vMPFC activation increases linearly with the personal importance attributed to self-representations. Third, the activity of the vMPFC is modulated by individual differences in the interest placed on self-reflection. Finally, the evidence shows that the vMPFC responds to outer aspects of self that have high personal value, such as possessions and close others. By assigning personal value to self-related contents, the vMPFC may play an important role in the construction, stabilization, and modification of self-representations, and ultimately in guiding our choices and decisions.