Treatment for social anxiety disorder alters functional connectivity in emotion regulation neural circuitry

Neural Responses to Auditory Food Stimuli Following Cognitive Behavioral Therapy for Binge-Eating Disorder

OBJECTIVE

Adults with binge-eating disorder (BED), compared with those without BED, demonstrate higher blood-oxygen-level-dependent (BOLD) response to food cues in reward-related regions of the brain. It is not known whether cognitive behavioral therapy (CBT) can reverse this reward system hyperactivation. This randomized controlled trial (RCT) assessed changes in BOLD response to binge-eating cues following CBT versus wait-list control (WLC).

METHOD

Females with BED (N = 40) were randomized to CBT or WLC. Participants completed assessments at baseline and 16 weeks including measures of eating and appetite and functional magnetic resonance imaging (fMRI) to measure BOLD response while listening to personalized scripts of binge-eating and neutral-relaxing cues. Data were analyzed using general linear models with mixed effects.

RESULTS

Overall retention rate was 87.5%. CBT achieved significantly greater reductions in binge-eating episodes than WLC (mean ± standard error decline of 14.6 ± 2.7 vs. 5.7 ± 2.8 episodes in the past 28 days, respectively; p = 0.03). CBT and WLC did not differ significantly in changes in neural responses to binge-eating stimuli during the fMRI sessions. Compared with WLC, CBT had significantly greater improvements in reward-based eating drive, disinhibition, and hunger as assessed by questionnaires (ps < 0.05).

DISCUSSION

CBT was effective in reducing binge eating, but, contrary to our hypothesis, CBT did not improve BOLD response to auditory binge-eating stimuli in reward regions of the brain. Further studies are needed to assess mechanisms underlying improvements with CBT for BED.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03604172.

An amygdala-centered effective connectivity network in trait anxiety

Previous studies have established that the amygdala plays an important role in trait anxiety. However, there remains limited knowledge regarding the changes in amygdala-centered effective connectivity network associated with this trait. The current study employed the Granger Causal analysis to investigate the directional connectivity patterns involving the amygdala in relation to trait anxiety in a large cohort of young adults (N = 424). The results revealed a negative association between trait anxiety scores and the Granger causality from the left middle frontal gyrus and right superior frontal gyrus to the right amygdala. Conversely, higher trait anxiety levels were found to be associated with increased effective connectivity from the left amygdala to the left hippocampus. These results demonstrated the significance of the prefrontal cortex-amygdala-hippocampus neural circuitry in the neurobiological mechanisms underlying trait anxiety. Our findings advance the comprehension of this characteristic, holding promise for informing strategies in the prevention and treatment of related mental disorders.

Individual cognitive therapy reduces frontal-thalamic resting-state functional connectivity in social anxiety disorder

Introduction

Previous neuroimaging studies in social anxiety disorders (SAD) have reported potential neural predictors of cognitive behavioral therapy (CBT)-related brain changes. However, several meta-analyses have demonstrated that cognitive therapy (CT) was superior to traditional exposure-based CBT for SAD.

Objective

To explore resting-state functional connectivity (rsFC) to evaluate the response to individual CT for SAD patients.

Methods

Twenty SAD patients who attended 16-week individual CT were scanned pre- and post-therapy along with twenty healthy controls (HCs). The severity of social anxiety was assessed with the Liebowitz Social Anxiety Scale (LSAS). Multi-voxel pattern analysis (MVPA) was performed on the pre-CT data to extract regions associated with a change in LSAS (∆LSAS). Group comparisons of the seed-based rsFC analysis were performed between the HCs and pre-CT patients and between the pre-and post-CT patients.

Results

MVPA-based regression analysis revealed that rsFC between the left thalamus and the frontal pole/inferior frontal gyrus was significantly correlated with ∆LSAS (adjusted R2 = 0.65; p = 0.00002). Compared with HCs, the pre-CT patients had higher rsFCs between the thalamus and temporal pole and between the thalamus and superior/middle temporal gyrus/planum temporale (p < 0.05). The rsFC between the thalamus and the frontal pole decreased post-CT (p < 0.05).

Conclusion

SAD patients had significant rsFC between the thalamus and temporal pole, superior/middle temporal gyrus, and planum temporale, which may be indicators of extreme anxiety in social situations. In addition, rsFC between the thalamus and the frontal pole may be a neuromarker for the effectiveness of individual CT.

An Examination of the Association between Emotion Regulation and Emetophobia Symptoms

BACKGROUND

Specific phobia of vomiting, referred to as emetophobia, is a specific phobia characterized by persistent and severe fear of vomit. Individuals with emetophobia engage in a variety of emotional and behavioral avoidance strategies to distance themselves from perceived vomit-related threat. As such, individuals may struggle to effectively use emotion regulation (ER) skills; however, to date, limited work has examined the association between emotion regulation and emetophobia symptoms. The present study aimed to address this gap in the literature and examine the association between ER and emetophobia symptoms.

METHODS

Participants (N = 508) were a remote, clinical sample of individuals recruited via social media forums dedicated to the disorder who self-identified as experiencing emetophobia. Hierarchical linear regressions were used to assessed unique contributions of ER to emetophobia symptoms. Age, gender, and depressive symptoms were entered as covariates in the hierarchical regression.

RESULTS

Results demonstrated ER was significantly related to emetophobia symptoms above and beyond the effects of depressive symptoms, age and gender in the current sample.

CONCLUSIONS

The findings provide initial support for an association between ER and emetophobia, and suggest future directions for refining the conceptualization of emetophobia. Limitations and considerations include the recruitment strategy via social media websites for individuals with emetophobia, limited diversity of the sample, and cross-sectional nature.

Moderating the link between discrimination and adverse mental health outcomes: Examining the protective effects of cognitive flexibility and emotion regulation

Discrimination is associated with mental health problems. While prior research has demonstrated the significance of emotion regulation in explaining the onset and development of discrimination-related anxiety, few studies investigated this dynamic with cognitive flexibility among sexual and/or racial minority individuals. The current study incorporated cognitive flexibility to investigate its potential buffering effects on discrimination-related anxiety. 221 individuals, 37.6% of whom (n = 83) identified as sexual and/or racial minorities, responded to an online questionnaire about their levels of cognitive flexibility and emotion regulation, perceived discrimination, and anxiety. Moderated mediation analyses were conducted with these variables. Our findings indicated that emotion regulation difficulty (ERD) mediated the relationship between discrimination and anxiety, while cognitive flexibility had a strong moderating effect on the relationship between ERD and anxiety. These results suggested new research directions and implied the therapeutic potential of advancing cognitive flexibility skills with emotion regulation training in depression and anxiety intervention and treatments. Future research is needed to investigate cognitive flexibility as a transdiagnostic mechanism underlying the onset and development of anxiety, to potentially lead to novel prevention or intervention for marginalized people facing additional stressors like discrimination.

When emotions cannot be efficiently used to guide attention: Flexible, goal-relevant utilization of facial emotions is hindered by social anxiety

In order to achieve optimal outcomes in diverse situations, emotional information can be used to initiate novel, goal-directed processes that are not inherently related to the emotional meaning. Demonstrating this goal-dependent flexibility, in a recent study, we presented facial emotions as informative spatial cues: Participants could direct their attention to the probable target location based on the expressed emotion with a remarkable efficiency (Folyi, Rohr, & Wentura, 2020). However, as inherent motivational aspects of threat-related facial expressions can be particularly salient to socially anxious individuals (e.g., Staugaard, 2010), they might not be able to use this information flexibly in the pursuit of a context-specific goal. The present study tested this assumption in an endogenous cueing task with anger and fear expressions as informative central cues. Indeed, in Experiment 1 (N = 174), higher social anxiety was associated with reduced cueing at a 600 ms cue-target asynchrony, and this deficit was specific to social as opposed to general anxiety. Furthermore, this effect occurred only when faces were presented upright (Experiment 1), and not under inverted presentation (Experiment 2, N = 90), ruling out a general deficit in attentional control. The results suggest that flexible utilization of threat-related emotional information is sensitive to participants' social anxiety, suggesting an imbalance between using emotional information in the pursuit of a context-dependent goal on the one hand, and processes intrinsically related to the emotional meaning on the other.

Threat Neurocircuitry Predicts the Development of Anxiety and Depression Symptoms in a Longitudinal Study

BACKGROUND

Owing to high heterogeneity and comorbidity, the shared and unique neural mechanisms underlying the development of anxiety and major depressive disorders remain unclear. Using a dimensional model describing shared versus unique symptoms associated with anxiety and depression, this study investigated how longitudinal changes in symptom dimensions relate to threat neurocircuitry.

METHODS

Participants were 18- to 19-year-olds (N = 279, 186 females) who completed self-report measures of anxiety and depression at baseline and at 10, 20, and 30 months. Linear slopes of symptom dimensions of general distress, fear, and anhedonia-apprehension were estimated through a trilevel factorial model. In addition, functional magnetic resonance imaging scans were obtained while participants performed Pavlovian fear conditioning tasks at baseline and 30 months, including three phases of fear acquisition, extinction, and extinction recall. Neural responses in regions of interest related to threat neural circuitry (e.g., amygdala, ventromedial prefrontal cortex, and subgenual anterior cingulate cortex) were extracted.

RESULTS

Linear mixed models used to estimate relationships between changes of symptom dimensions and neural responses revealed two major findings: 1) greater neural responses to threatening stimuli during fear acquisition at baseline were associated with a greater increase in fear symptoms during the 30-month prospective period; and 2) elevated neural responses to the extinguished stimulus during extinction recall at 30 months were negatively associated with changes in general distress, suggesting that greater increases in general distress are associated with larger deficits in extinction memory.

CONCLUSIONS

These findings improve our understanding of pathophysiological pathways underlying the development of anxiety and depression, while separating symptom dimensions that are shared versus unique between the two disorders.

Functional neural changes associated with psychotherapy in anxiety disorders - A meta-analysis of longitudinal fMRI studies

Successful psychotherapy for anxiety disorders is thought to be linked to functional neural changes in prefrontal control areas and fear-related limbic regions. Thus, discovering such therapy-associated neural changes might point to relevant mechanisms of action. Using AES-SDM, we conducted a coordinate-based meta-analysis of 22 whole-brain datasets (n = 419 anxiety patients) from 18 studies identified by our systematic literature search following PRISMA criteria (preregistration available at OSF: https://osf.io/dgc4p). In these studies, fMRI data was collected in response to negative stimuli during cognitive-emotional tasks before and after psychotherapy. Post-psychotherapy, activation decreased in the right insula, the anterior cingulate cortex, and the dorsolateral prefrontal cortex; no region had increased activation. A subgroup analysis for CBT revealed additional decrease in the supplementary motor area. Reduced activation in limbic and frontal regions might indicate therapy-associated normalization regarding the perception of internal and external threat, subsequent allocation of cognitive resources, and changes in effortful cognitive control. Due to the integration of diverse treatments and experimental tasks, these changes presumably reflect global effects of successful psychotherapy.

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.

Neurocircuitry of Treatment in Anxiety Disorders

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Methods:

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Behavioral, cortical and autonomic effects of single-dose escitalopram on the induction and regulation of fear and disgust: Comparison with single-session psychological emotion regulation with reappraisal

INTRODUCTION

Adaptive and successful emotion regulation, the ability to flexibly exert voluntary control over emotional experience and the ensuing behavior, is vital for optimal daily functioning and good mental health. In clinical settings, pharmacological and psychological interventions are widely employed to modify pathological emotion processing and ameliorate its deleterious consequences.

METHODS

In this study, we investigated the acute effects of single-dose escitalopram on the induction and regulation of fear and disgust in healthy subjects. Furthermore, we compared these pharmacological effects with psychological emotion regulation that utilized a cognitive strategy with reappraisal. Emotion induction and regulation tasks were performed before and 4 h after ingestion of placebo or 10 mg escitalopram in a randomized, double-blind design. The International Affective Picture System (IAPS) was used as a source of images, with threat-related pictures selected for fear and disease and contamination-related pictures for disgust. Behavioral data, electrodermal activity (EDA), and functional near-infrared spectroscopy (fNIRS) recordings were collected.

RESULTS

Escitalopram significantly reduced emotion intensity for both fear and disgust during emotion induction, albeit with differing electrodermal and hemodynamic activity patterns for the two negative emotions. At rest, i.e., in the absence of emotive stimuli, escitalopram increased sympathetic activity during the fear but not during the disgust experiments. For both fear and disgust, emotion regulation with reappraisal was more effective in reducing emotion intensity compared to pharmacological intervention with escitalopram or placebo.

DISCUSSION

We concluded that emotion regulation with reappraisal and acute administration of escitalopram, but not placebo, reduce emotion intensity for both fear and disgust, with cognitive regulation being significantly more efficient compared to pharmacological regulation under the conditions of this study. Results from the fNIRS and EDA recordings support the concept of differential mechanisms of emotion regulation that could be emotion-specific.

Acceptance and Commitment Therapy in a Low-Income Country in Sub-Saharan Africa: A Call for Further Research

A worsening trend of critical shortages in senior health care workers across low- and middle-income countries (LMICs) in sub-Saharan Africa has been documented for decades. This is especially the case in Ethiopia that has severe shortage of mental health professionals. Consistent with the WHO recommended approach of task sharing for mental health care in LMICs, Acceptance and Commitment Therapy (ACT), which is an empirically validated psychological intervention aimed at increasing psychological flexibility, may be delivered by trained laypersons who have a grassroots presence. In this paper, we discuss the need for and potential role of ACT to be delivered by health extension workers (HEWs) to address mental health care needs across Ethiopia. To this end, we also reviewed previous studies that have examined the effectiveness of ACT-based interventions in African countries including in Nigeria, Sierra Leone, Uganda, and South Africa. All studies revealed significant improvements of various mental health-related outcome measures such as decreased psychological distress and depressive symptoms, or increased subjective wellbeing and life satisfaction in the groups that received an ACT-based intervention. However, to date, there is no study that applied ACT in Ethiopia. Thus, more research is warranted to examine the effectiveness and, if proven successful, to scale up a task sharing approach of an ACT-based intervention being delivered by trained HEWs at a grassroots level, possibly paving the way for an innovative, sustainable mental health service in Ethiopia as well as other African LMICs.

Neural correlates of emotional reactivity and regulation in youth with and without anxiety

BACKGROUND

Youth with anxiety disorders struggle with managing emotions relative to peers, but the neural basis of this difference has not been examined.

METHODS

Youth (M_age  = 13.6; range = 8-17) with (n = 37) and without (n = 24) anxiety disorders completed a cognitive reappraisal task while undergoing functional magnetic resonance imaging. Emotional reactivity and regulation, functional activation, and beta-series connectivity were compared across groups.

RESULTS

Groups did not differ on emotional reactivity or regulation. However, fronto-limbic activation after viewing aversive imagery with and without regulation, as well as affect ratings without regulation, were higher for anxious youth. Neither group demonstrated age-related changes in regulation, though anxious youth became less reactive with age. Stronger amygdala-ventromedial prefrontal cortex connectivity related to greater anxiety in control youth, but less anxiety in anxious youth.

CONCLUSION

Anxious youth regulated when instructed, but regulation ability did not relate to age. Viewing aversive imagery related to heightened fronto-limbic activation even after reappraisal. Emotion dysregulation in youth anxiety disorders may stem from heightened emotionality and potent bottom-up neurobiological responses to aversive stimuli. Findings suggest the importance of treatments focused on both reducing initial emotional reactivity and bolstering regulatory capacity.

Neural mechanisms and predictors of SSRI and CBT treatment of anxiety: A randomized trial focused on emotion and cognitive processing

Anxiety disorders (ADs) are common and difficult to treat. While research suggests ADs are characterized by an imbalance between bottom-up and top-down attention processes and that effective treatments work by correcting this dysfunction, there is insufficient data to explain how and for whom treatments work. The late positive potential (LPP), an event-related potential reflecting elaborative processing of motivationally salient stimuli, is sensitive to both bottom-up and top-down processes. The present study examines the LPP in healthy controls (HC) and patients with ADs under low and high working memory (WM) load to assess its utility as a predictor and index of symptom reduction in patients who underwent cognitive behavioral therapy (CBT) or selective serotonin reuptake inhibitor (SSRI) treatment. The LPP when viewing negative and neutral distractor images and WM performance were assessed in 96 participants (40 HC, 32 CBT, 24 SSRI) during a letter recall task at Week 0 and in a subset of the study sample (23 CBT, 16 SSRI) at Week 12. Patients were randomly assigned to twelve weeks of CBT or SSRI treatment. Participants completed self-reported symptom measures at each time point. Greater Week 0 LPP to negative images under low WM load predicted greater symptom reduction in the SSRI, but not the CBT, group. Regression analyses examining the LPP to negative images as an index of symptom reduction revealed a smaller decrease in the LPP to negative images under low WM load was associated with less anxiety reduction across treatment modalities. Findings suggest the LPP during low WM load may serve as a cost-effective predictor and index of treatment outcome in ADs. Clinical Trials Registration: ClinicalTrials.gov (Identifier: NCT01903447).

Brain markers predicting response to cognitive-behavioral therapy for social anxiety disorder: an independent replication of Whitfield-Gabrieli et al. 2015

Predictive brain markers promise a number of important scientific, clinical, and societal applications. Over 600 predictive brain markers have been described in published reports, but very few have been tested in independent replication attempts. Here, we conducted an independent replication of a previously published marker predicting treatment response to cognitive-behavioral therapy for social anxiety disorder from patterns of resting-state fMRI amygdala connectivity1. The replication attempt was conducted in an existing dataset similar to the dataset used in the original report, by a team of independent investigators in consultation with the original authors. The precise model described in the original report positively predicted treatment outcomes in the replication dataset, but with marginal statistical significance, permutation test p = 0.1. The effect size was substantially smaller in the replication dataset, with the model explaining 2% of the variance in treatment outcomes, as compared to 21% in the original report. Several lines of evidence, including the current replication attempt, suggest that features of amygdala function or structure may be able to predict treatment response in anxiety disorders. However, predictive models that explain a substantial amount of variance in independent datasets will be needed for scientific and clinical applications.

Delta-beta cross-frequency coupling as an index of stress regulation during social-evaluative threat

Coupling between delta (1-4 Hz) and beta (14-30 Hz) oscillations is posited to reflect subcortico-cortical communication and stress regulation. To validate delta-beta coupling (DBC) as an index of neural stress regulation, we investigated whether DBC changes during stress and whether these changes are associated with established stress responses. We induced stress using a social-evaluative threat (impromptu speech) task and measured frontal and parietal delta-beta amplitude-amplitude correlation (AAC) and phase-amplitude coupling (PAC), as well as cardiovascular, affective, and endocrine stress responses. Results showed no significant changes in either AAC or PAC in response to stress and no correlations with stress responses. However, baseline AAC tended to be related to more adaptive endocrine stress responses. Our results suggest that delta-beta AAC or PAC are not valid neural indices of stress regulation itself, but rather traits that relate to differences in neuroendocrine stress responses.

Training negative connectivity patterns between the dorsolateral prefrontal cortex and amygdala through fMRI-based neurofeedback to target adolescent socially-avoidant behaviour

Social anxiety is prevalent in adolescence. Given its role in maintaining fears, reducing social avoidance through cognitive reappraisal may help attenuate social anxiety. We used fMRI-based neurofeedback (NF) to increase 'adaptive' patterns of negative connectivity between the dorsolateral prefrontal cortex (DLPFC) and the amygdala to change reappraisal ability, and alter social avoidance and approach behaviours in adolescents. Twenty-seven female participants aged 13-17 years with varying social anxiety levels completed a fMRI-based NF training task where they practiced cognitive reappraisal strategies, whilst receiving real-time feedback of DLPFC-amygdala connectivity. All participants completed measures of cognitive reappraisal and social approach-avoidance behaviour before and after NF training. Avoidance of happy faces was associated with greater social anxiety pre-training. Participants who were unable to acquire a more negative pattern of connectivity through NF training displayed significantly greater avoidance of happy faces at post-training compared to pre-training. These 'maladaptive' participants also reported significant decreases in re-appraisal ability from pre to post-training. In contrast, those who were able to acquire a more 'adaptive' connectivity pattern did not show these changes in social avoidance and re-appraisal. Future research could consider using strategies to improve the capacity of NF training to boost youth social-approach behaviour.

Dynamic Neural Interactions Supporting the Cognitive Reappraisal of Emotion

The cognitive reappraisal of emotion is hypothesized to involve frontal regions modulating the activity of subcortical regions such as the amygdala. However, the pathways by which structurally disparate frontal regions interact with the amygdala remains unclear. In this study, 104 healthy young people completed a cognitive reappraisal task. Dynamic causal modeling (DCM) was used to map functional interactions within a frontoamygdalar network engaged during emotion regulation. Five regions were identified to form the network: the amygdala, the presupplementary motor area (preSMA), the ventrolateral prefrontal cortex (vlPFC), dorsolateral prefrontal cortex (dlPFC), and ventromedial prefrontal cortex (vmPFC). Bayesian Model Selection was used to compare 256 candidate models, with our winning model featuring modulations of vmPFC-to-amygdala and amygdala-to-preSMA pathways during reappraisal. Moreover, the strength of amygdala-to-preSMA modulation was associated with the habitual use of cognitive reappraisal. Our findings support the vmPFC serving as the primary conduit through which prefrontal regions directly modulate amygdala activity, with amygdala-to-preSMA connectivity potentially acting to shape ongoing affective motor responses. We propose that these two frontoamygdalar pathways constitute a recursive feedback loop, which computes the effectiveness of emotion-regulatory actions and drives model-based behavior.

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

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

Prefrontal-amygdala connectivity in trait anxiety and generalized anxiety disorder: Testing the boundaries between healthy and pathological worries

BACKGROUND

Current brain-based theoretical models of generalized anxiety disorder (GAD) suggest a dysfunction of amygdala-ventromedial prefrontal cortex emotional regulatory mechanisms. These alterations might be reflected by an altered resting state functional connectivity between both areas and could extend to vulnerable non-clinical samples such as high worriers without a GAD diagnosis. However, there is a lack of information in this regard.

METHODS

We investigated differences in resting state functional connectivity between the basolateral amygdala and the ventromedial prefrontal cortex (amygdala-vmPFC) in 28 unmedicated participants with GAD, 28 high-worriers and 28 low-worriers. We additionally explored selected clinical variables as predictors of amygdala-vmPFC connectivity, including anxiety sensitivity.

RESULTS

GAD participants presented higher left amygdala-vmPFC connectivity compared to both groups of non-GAD participants, and there were no differences between the latter two groups. In our exploratory analyses, concerns about the cognitive consequences of anxiety (the cognitive dimension of anxiety sensitivity) were found to be a significant predictor of the left amygdala-vmPFC connectivity.

LIMITATIONS

The cross-sectional nature of our study preclude us from assessing if functional connectivity measures and anxiety sensitivity scores entail an increased risk of GAD.

CONCLUSIONS

These results suggest a neurobiological qualitative distinction at the level of the amygdala-vmPFC emotional-regulatory system in GAD compared to non-GAD participants, either high- or low-worriers. At this neural level, they question previous hypotheses of continuity between high worries and GAD development. Instead, other anxiety traits such as anxiety sensitivity might confer a greater proneness to the amygdala-vmPFC connectivity alterations observed in GAD.

Imaging the socially-anxious brain: recent advances and future prospects

Social anxiety disorder (SAD) is serious psychiatric condition with a genetic background. Insight into the neurobiological alterations underlying the disorder is essential to develop effective interventions that could relieve SAD-related suffering. In this expert review, we consider recent neuroimaging work on SAD. First, we focus on new results from magnetic resonance imaging studies dedicated to outlining biomarkers of SAD, including encouraging findings with respect to structural and functional brain alterations associated with the disorder. Furthermore, we highlight innovative studies in the field of neuroprediction and studies that established the effects of treatment on brain characteristics. Next, we describe novel work aimed to delineate endophenotypes of SAD, providing insight into the genetic susceptibility to develop the disorder. Finally, we outline outstanding questions and point out directions for future research.

A mechanistic model for individualised treatment of anxiety disorders based on predictive neural biomarkers

Increased amygdala responsiveness is the hallmark of fear and a characteristic across patients with anxiety disorders. The amygdala is embedded in a complex regulatory circuit. Multiple different mechanisms may elevate amygdala responsiveness and lead to the occurrence of an anxiety disorder. While top-down control by the prefrontal cortex (PFC) downregulates amygdala responses, the locus coeruleus (LC) drives up amygdala activation via noradrenergic projections. This indicates that the same fearful phenotype may result from different neural mechanisms. We propose a mechanistic model that defines three different neural biomarkers causing amygdala hyper-responsiveness in patients with anxiety disorders: (a) inherent amygdala hypersensitivity, (b) low prefrontal control and (c) high LC drive. First-line treatment for anxiety disorders is exposure-based cognitive behavioural therapy, which strengthens PFC recruitment during emotion regulation and thus targets low-prefrontal control. A treatment response rate around 50% (Loerinc et al., 2015, Clinical Psychological Reviews, 42, 72-82) might indicate heterogeneity of underlying neurobiological mechanisms among patients, presumably leading to high variation in treatment benefit. Transforming insights from cognitive neuroscience into applicable clinical heuristics to categorise patients based on their underlying biomarker may support individualised treatment selection in psychiatry. We review literature on the three anxiety-related mechanisms and present a mechanistic model that may serve as a rational for pathology-based diagnostic and biomarker-guided treatment selection in psychiatry.

Changes in functional connectivity with cognitive behavioral therapy for social anxiety disorder predict outcomes at follow-up

Approximately half of individuals with Social Anxiety Disorder (SAD) treated with psychological intervention do not achieve clinically significant improvement or retain long-term gains. Neurobiological models of SAD propose that disruptions in functioning of amygdala-prefrontal circuitry is implicated in short-term treatment response. However, whether treatment-related changes in functional connectivity predict long-term well-being after psychotherapy is unknown. Patients with SAD completed an incidental emotion regulation task during fMRI before and after treatment with cognitive behavioral therapy or acceptance and commitment therapy (n = 23, collapsed across groups). Psychophysiological interaction analyses using amygdala seed regions were conducted to assess changes in functional connectivity from pre-to post-treatment that predicted symptom change from 6 to 12-month follow-up. Negative change (i.e., greater inverse/weaker positive) in amygdala connectivity with the dorsomedial prefrontal cortex (dmPFC) and dorsal anterior cingulate cortex (dACC) predicted greater symptom reduction during follow-up. Positive change in amygdala connectivity with the cerebellum, fusiform gyrus, and pre-central and post-central gyri predicted less symptom reduction (e.g., no change or worsening). Results suggest that strengthened amygdala connectivity with regulatory regions may promote better long-term outcomes, whereas changes with visual and sensorimotor regions may represent sensitization to emotion-related cues, conferring poorer outcomes. Clinical implications for treatment personalization are discussed, should effects replicate in larger samples.

Preliminary Evidence That CD38 Moderates the Association of Neuroticism on Amygdala-Subgenual Cingulate Connectivity

CD38 genetic variation has been associated with autism spectrum disorders and social anxiety disorder, which may result from CD38’s regulation of oxytocin secretion. Converging evidence has found that the rs3796863 A-allele contributes to increased social sensitivity compared to the CC genotype. The current study examined the moderating role of CD38 genetic variants (rs3796863 and rs6449182) that have been associated with enhanced (or reduced) social sensitivity on neural activation related to neuroticism, which is commonly elevated in individuals with social anxiety and depression. Adults (n = 72) with varying levels of social anxiety and depression provided biological samples for DNA extraction, completed a measure of neuroticism, and participated in a standardized emotion processing task (affect matching) while undergoing fMRI. A significant interaction effect was found for rs3796863 x neuroticism that predicted right amygdala-subgenual anterior cingulate cortex (sgACC) functional connectivity. Simple slopes analyses showed a positive association between neuroticism and right amygdala-sgACC connectivity among rs3796863 A-allele carriers. Findings suggest that the more socially sensitive rs3796863 A-allele may partially explain the relationship between a known risk factor (i.e. neuroticism) and promising biomarker (i.e. amygdala-sgACC connectivity) in the development and maintenance of social anxiety and depression.

Nucleus accumbens volume as a predictor of anxiety symptom improvement following CBT and SSRI treatment in two independent samples

Structural variations of neural regions implicated in fear responses have been well documented in the pathophysiology of anxiety and may play an important role in treatment response. We examined whether gray matter volume of three neural regions supporting fear and avoidance responses [bilateral amygdala, nucleus accumbens (NAcc), and ventromedial prefrontal cortex (PFC)] predicted cognitive-behavioral therapy (CBT) and selective serotonin reuptake inhibitor (SSRI) treatment outcome in two independent samples of patients with anxiety disorders. Study 1 consisted of 81 adults with anxiety disorders and Study 2 included 55 children and adolescents with anxiety disorders. In both studies, patients completed baseline structural MRI scans and received either CBT or SSRI treatment. Clinician-rated interviews of anxiety symptoms were assessed at baseline and posttreatment. Among the adult sample, greater pre-treatment bilateral NAcc volume was associated with a greater reduction in clinician-rated anxiety symptoms pre-to-post CBT and SSRI treatment. Greater left NAcc volume also predicted greater decreases in clinician-rated anxiety symptoms pre-to-post CBT and SSRI treatment among youth with current anxiety. Across studies, results were similar across treatments, and findings were maintained when adjusting for patient's age, sex, and total intracranial brain volume. We found no evidence for baseline amygdala or ventromedial PFC volume serving as treatment predictors across the two samples. Together, these findings provide promising support for the role of NAcc volume as an objective marker of anxiety treatment improvement that spans across development. Future studies should clarify the specific mechanisms through which NAcc volume exerts its therapeutic effects.

Emotion-based brain mechanisms and predictors for SSRI and CBT treatment of anxiety and depression: a randomized trial

Mechanisms and predictors for the successful treatment of anxiety and depression have been elusive, limiting the effectiveness of existing treatments and curtailing the development of new interventions. In this study, we evaluated the utility of three widely used neural probes of emotion (experience, regulation, and perception) in their ability to predict symptom improvement and correlate with symptom change following two first-line treatments-selective serotonin reuptake inhibitors (SSRIs) and cognitive-behavioral therapy (CBT). Fifty-five treatment-seeking adults with anxiety and/or depression were randomized to 12 weeks of SSRI or CBT treatment (ClinicalTrials.gov identifier: NCT01903447). Functional magnetic resonance imaging (fMRI) was used to examine frontolimbic brain function during emotion experience, regulation, and perception, as probed by the Emotion Regulation Task (ERT; emotion experience and regulation) and emotional face assessment task (EFAT; emotion perception). Brain function was then related to anxiety and depression symptom change. Results showed that both SSRI and CBT treatments similarly attenuated insula and amygdala activity during emotion perception, and greater treatment-related decrease in insula and amygdala activity was correlated with greater reduction in anxiety symptoms. Both treatments also reduced amygdala activity during emotion experience but brain change did not correlate with symptom change. Lastly, greater pre-treatment insula and amygdala activity during emotion perception predicted greater anxiety and depression symptom improvement. Thus, limbic activity during emotion perception is reduced by both SSRI and CBT treatments, and predicts anxiety and depression symptom improvement. Critically, neural reactivity during emotion perception may be a non-treatment-specific mechanism for symptom improvement.

Neuroimaging findings as predictors of treatment outcome of psychotherapy in anxiety disorders

Anxiety disorders are the largest group of mental disorders and a leading cause of impairment, implicating in high costs for health systems and society. Effective pharmacological and psychological treatments are available, but a significant fraction of these patients does not respond adequately to these treatments. The objective of this study is to identify neuroimaging findings that could predict response to psychotherapy in anxiety disorders.

METHODS

The authors reviewed psychotherapy clinical trials with neuroimaging conducted with patients with anxiety disorders. A systematic review was performed in MEDLINE database through PubMed, the Cochrane Collaboration's Clinical Trials Register (CENTRAL), PsycINFO and Thomson Reuters's Web of Science.

RESULTS

From the studies included in this review, 24 investigated anxiety disorder patients, and findings in the amygdala, dorsolateral prefrontal cortex (dlPFC), anterior cingulate cortex (ACC) and insula predicted response to psychotherapy in social anxiety disorder. Findings in ACC, hippocampus, insula, dlPFC, amygdala and inferior frontal gyrus (iFG) predicted response to psychotherapy in panic disorder and generalized anxiety disorder.

LIMITATIONS

There was great heterogeneity between the included studies regarding neuroimaging techniques and the tasks performed during functional neuroimaging.

CONCLUSION

Neuroimaging studies suggest that abnormalities in hippocampus, amygdala, iFG, uncus and areas linked with emotional regulation (dlPFC and ACC), predict a good outcome to psychotherapy in anxiety disorders.

Positive and Negative Emotion Regulation in Adolescence: Links to Anxiety and Depression

Emotion regulation skills develop substantially across adolescence, a period characterized by emotional challenges and developing regulatory neural circuitry. Adolescence is also a risk period for the new onset of anxiety and depressive disorders, psychopathologies which have long been associated with disruptions in regulation of positive and negative emotions. This paper reviews the current understanding of the role of disrupted emotion regulation in adolescent anxiety and depression, describing findings from self-report, behavioral, peripheral psychophysiological, and neural measures. Self-report studies robustly identified associations between emotion dysregulation and adolescent anxiety and depression. Findings from behavioral and psychophysiological studies are mixed, with some suggestion of specific impairments in reappraisal in anxiety. Results from neuroimaging studies broadly implicate altered functioning of amygdala-prefrontal cortical circuitries, although again, findings are mixed regarding specific patterns of altered neural functioning. Future work may benefit from focusing on designs that contrast effects of specific regulatory strategies, and isolate changes in emotional regulation from emotional reactivity. Approaches to improve treatments based on empirical evidence of disrupted emotion regulation in adolescents are also discussed. Future intervention studies might consider training and measurement of specific strategies in adolescents to better understand the role of emotion regulation as a treatment mechanism.

Emotion dysregulation and functional connectivity in children with and without a history of major depressive disorder

Recent interest has emerged in understanding the neural mechanisms by which deficits in emotion regulation (ER) early in development may relate to later depression. Corticolimbic alterations reported in emotion dysregulation and depression may be one possible link. We examined the relationships between emotion dysregulation in school age, corticolimbic resting-state functional connectivity (rs-FC) in preadolescence, and depressive symptoms in adolescence. Participants were 143 children from a longitudinal preschool onset depression study who completed the Children Sadness Management Scale (CSMS; measuring ER), Child Depression Inventory (CDI-C; measuring depressive symptoms), and two resting-state MRI scans. Rs-FC between four primary regions of interest (ROIs; bilateral dorsolateral prefrontal cortex [dlPFC] and amygdala) and six target ROIs thought to contribute to ER were examined. Findings showed that ER in school age did not predict depressive symptoms in adolescence, but did predict preadolescent increases in dlPFC-insula and dlPFC-ventromedial PFC rs-FC across diagnosis, as well as increased dlPFC-dorsal anterior cingulate cortex (dACC) rs-FC in children with a history of depression. Of these profiles, only dlPFC-dACC rs-FC in preadolescence predicted depressive symptoms in adolescence. However, dlPFC-dACC connectivity did not mediate the relationship between ER in school age and depressive symptoms in adolescence. Despite the absence of a direct relationship between ER and depressive symptoms and no significant rs-FC mediation, the rs-FC profiles predicted by ER are consistent with the hypothesis that emotion dysregulation is associated with abnormalities in top-down control functions. The extent to which these relationships might confer greater risk for later depression, however, remains unclear.

Self-referential processing during observation of a speech performance task in social anxiety disorder from pre- to post-treatment: Evidence of disrupted neural activation

Self-referential processing is critical to understanding social anxiety disorder (SAD). This study examined neural differences in self-referential processing in healthy controls (HC) and participants with SAD at pre- and post-treatment. Participants (n = 64) underwent fMRI scanning while viewing a video of themselves ("Self") or another person ("Other"). SAD participants were randomized to cognitive behavior therapy (CBT), acceptance and commitment therapy (ACT), or waitlist, and were re-scanned at post-treatment. In SAD vs. HC, the fusiform face area (FFA) showed significantly more activation during Self vs. Other, and greater SAD severity was associated with significantly more activation during Self vs. Other in the right FFA and the left extrastriate body area (EBA). Greater reduction in SAD severity was associated with stronger connectivity between the amygdala and FFA during Self vs. Other at post-treatment, whereas the strength of connectivity during Self and Other was comparable at post-treatment for those with less SAD reduction. Thus, there were significant differences in activation and functional connectivity of brain regions implicated in self-referential processing in SAD. Change in connectivity between the amygdala and FFA were observed as a function of change in SAD severity, suggesting that improvements in SAD severity may correct this altered functional connectivity.

Neural connectivity during affect labeling predicts treatment response to psychological therapies for social anxiety disorder

BACKGROUND

Although psychological treatments for social anxiety disorder (SAD) can be highly effective, many individuals do not respond to treatment. Identifying factors associated with improved outcomes can facilitate individualized treatment choices. We investigated whether patterns of neural connectivity predicted treatment responses and whether treatment type, cognitive behavioral therapy (CBT) or acceptance and commitment therapy (ACT), moderated this effect.

METHODS

Participants with SAD (n = 34) underwent fMRI prior to treatment and completed implicit and explicit emotion regulation tasks. Neural connectivity measures were estimates of amygdala-prefrontal cortex connectivity. Treatment responder status was defined using the 'clinically significant change index' (Loerinc et al., 2015).

RESULTS

Right amygdala-right ventrolateral prefrontal cortex connectivity during implicit emotion regulation was a significant predictor of treatment response (OR = 9.01, 95% CI = 1.77, 46.0, p = .008). Stronger inverse connectivity was associated with greater likelihood of treatment response. There were no significant neural moderators of treatment response to CBT versus ACT.

LIMITATIONS

The primary limitation of this work was the small sample size which restricted the power to detect significant moderation effects, and results should be interpreted as preliminary.

CONCLUSIONS

Amygdala-vlPFC connectivity during affect labeling predicted treatment responder status following CBT or ACT for social anxiety disorder. This suggests that the functioning of neural circuitry supporting emotion regulation capacities may be a 'gateway' to receiving benefit from psychological treatments. Future work should aim to replicate this effect in a larger sample and consider methods for enhancing functional connectivity within this circuitry as a potential treatment adjunct.

Randomized controlled trial of cognitive behavioural therapy for depressive and anxiety symptoms in Chinese women with breast cancer

Depressive and anxiety symptoms are frequently observed in breast cancer survivors. To date, few randomized controlled trials have been conducted on the efficacy of cognitive behavioural therapy (CBT) for depressive and anxiety symptoms in Chinese population. This study aims to verify the efficacy of CBT in Chinese breast cancer survivors. Women (n = 392) with breast cancer were randomly assigned to 3 groups: CBT (n = 98), self-care management (SCM, n = 98), and usual care (UC, n = 196) using the proportion 1:1:2. Women in the CBT and SCM groups received a series of nine sessions for 12 weeks, while women in the UC group received their usual medical care only. Depressive and anxiety symptoms were assessed using the Hamilton Depression Rating Scale (HAMD) and the Hamilton Anxiety Scale (HAMA) score at baseline, 2, 4, 8, 12, 16, and 24 weeks. A significant intergroup difference was found in the HAMD and HAMA scores. Women in the CBT group showed significantly less depressive and anxiety symptoms compared with women in the SCM and UC groups over time. In conclusion, this study supports the efficacy of CBT for depressive and anxiety symptoms in Chinese breast cancer survivors.

Neuroimaging Predictors and Mechanisms of Treatment Response in Social Anxiety Disorder: an Overview of the Amygdala

PURPOSE OF REVIEW

Aberrant amygdala activity is implicated in the neurobiology of social anxiety disorder (SAD) and is, therefore, a treatment target. However, the extent to which amygdala predicts clinical improvement or is impacted by treatment has not been critically examined. This review highlights recent neuroimaging findings from clinical trials and research that test links between amygdala and mechanisms of action.

RECENT FINDINGS

Neuropredictor studies largely comprised psychotherapy where improvement was foretold by amygdala activity and regions beyond amygdala such as frontal structures (e.g., anterior cingulate cortex, medial prefrontal cortex) and areas involved in visual processes (e.g., occipital regions, superior temporal gyrus). Pre-treatment functional connectivity between amygdala and frontal areas was also shown to predict improvement signifying circuits that support emotion processing and regulation interact with treatment. Pre-to-post studies revealed decreases in amygdala response and altered functional connectivity in amygdala pathways regardless of treatment modality. In analogue studies of fear exposure, greater reduction in anxiety was predicted by less amygdala response to a speech challenge and amygdala activity decreased following exposures. Yet, studies have also failed to detect amygdala effects reporting instead treatment-related changes in regions and functional systems that support sensory, emotion, and regulation processes. An array of regions in the corticolimbic subcircuits and extrastriate cortex appear to be viable sites of action. The amygdala and amygdala pathways predict treatment outcome and are altered following treatment. However, further study is needed to establish the role of the amygdala and other candidate regions and brain circuits as sites of action.

An Integrative Neuroscience Framework for the Treatment of Chronic Pain: From Cellular Alterations to Behavior

Chronic pain can result from many pain syndromes including complex regional pain syndrome (CRPS), phantom limb pain and chronic low back pain, among others. On a molecular level, chronic pain syndromes arise from hypersensitization within the dorsal horn of the spinal cord, a process known as central sensitization. Central sensitization involves an upregulation of ionotropic and metabotropic glutamate receptors (mGluRs) similar to that of long-term potentiation (LTP). Regions of the brain in which LTP occurs, such as the amygdala and hippocampus, are implicated in fear- and memory-related brain circuity. Chronic pain dramatically influences patient quality of life. Individuals with chronic pain may develop pain-related anxiety and pain-related fear. The syndrome also alters functional connectivity in the default-mode network (DMN) and salience network. On a cellular/molecular level, central sensitization may be reversed through degradative glutamate receptor pathways. This, however, rarely happens. Instead, cortical brain regions may serve in a top-down regulatory capacity for the maintenance or alleviation of pain. Specifically, the medial prefrontal cortex (mPFC), which plays a critical role in fear-related brain circuits, the DMN, and salience network may be the driving forces in this process. On a cellular level, the mPFC may form new neural circuits through LTP that may cause extinction of pre-existing pain pathways found within fear-related brain circuits, the DMN, and salience network. In order to promote new LTP connections between the mPFC and other key brain structures, such as the amygdala and insula, we propose a holistic rehabilitation program including cognitive behavioral therapy (CBT) and revolving around: (1) cognitive reappraisals; (2) mindfulness meditation; and (3) functional rehabilitation. Unlike current medical interventions focusing upon pain-relieving medications, we do not believe that chronic pain treatment should focus on reversing the effects of central sensitization. Instead, we propose here that it is critical to focus on non-invasive efforts to promote new neural circuits originating from the mPFC.

Speech Disfluency-dependent Amygdala Activity in Adults Who Stutter: Neuroimaging of Interpersonal Communication in MRI Scanner Environment

Affective states, such as anticipatory anxiety, critically influence speech communication behavior in adults who stutter. However, there is currently little evidence regarding the involvement of the limbic system in speech disfluency during interpersonal communication. We designed this neuroimaging study and experimental procedure to sample neural activity during interpersonal communication between human participants, and to investigate the relationship between the amygdala activity and speech disfluency. Participants were required to engage in live communication with a stranger of the opposite sex in the MRI scanner environment. In the gaze condition, the stranger gazed at the participant without speaking, while in the live conversation condition, the stranger asked questions that the participant was required to answer. The stranger continued to gaze silently at the participant while the participant answered. Adults who stutter reported significantly higher discomfort than fluent controls during the experiment. Activity in the right amygdala, a key anatomical region in the limbic system involved in emotion, was significantly correlated with stuttering occurrences in adults who stutter. Right amygdala activity from pooled data of all participants also showed a significant correlation with discomfort level during the experiment. Activity in the prefrontal cortex, which forms emotion regulation neural circuitry with the amygdala, was decreased in adults who stutter than in fluent controls. This is the first study to demonstrate that amygdala activity during interpersonal communication is involved in disfluent speech in adults who stutter.

Imaging and Genetic Approaches to Inform Biomarkers for Anxiety Disorders, Obsessive-Compulsive Disorders, and PSTD

Anxiety disorders are the most common mental health problem in the world and also claim the highest health care cost among various neuropsychiatric disorders. Anxiety disorders have a chronic and recurrent course and cause significantly negative impacts on patients' social, personal, and occupational functioning as well as quality of life. Despite their high prevalence rates, anxiety disorders have often been under-diagnosed or misdiagnosed, and consequently under-treated. Even with the correct diagnosis, anxiety disorders are known to be difficult to treat successfully. In order to implement better strategies in diagnosis, prognosis, treatment decision, and early prevention for anxiety disorders, tremendous efforts have been put into studies using genetic and neuroimaging techniques to advance our understandings of the underlying biological mechanisms. In addition to anxiety disorders including panic disorder, generalised anxiety disorder (GAD), specific phobias, social anxiety disorders (SAD), due to overlapping symptom dimensions, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD) (which were removed from the anxiety disorder category in DSM-5 to become separate categories) are also included for review of relevant genetic and neuroimaging findings. Although the number of genetic or neuroimaging studies focusing on anxiety disorders is relatively small compare to other psychiatric disorders such as psychotic disorders or mood disorders, various structural abnormalities in the grey or white matter, functional alterations of activity during resting-state or task conditions, molecular changes of neurotransmitter receptors or transporters, and genetic associations have all been reported. With continuing effort, further genetic and neuroimaging research may potentially lead to clinically useful biomarkers for the prevention, diagnosis, and management of these disorders.

Amygdalar expression of the microRNA miR-101a and its target Ezh2 contribute to rodent anxiety-like behaviour

A greater understanding of neural mechanisms contributing to anxiety is needed in order to develop better therapeutic interventions. This study interrogates a novel molecular mechanism that shapes anxiety-like behaviour, demonstrating that the microRNA miR-101a-3p and its target, enhancer of zeste homolog 2 (Ezh2) in the amygdala, contribute to rodent anxiety-like behaviour. We utilized rats that were selectively bred for differences in emotionality and stress reactivity, showing that high-novelty-responding (HR) rats, which display low trait anxiety, have lower miR-101a-3p levels in the amygdala compared to low-novelty-responding (LR) rats that characteristically display high trait anxiety. To determine whether there is a causal relationship between amygdalar miR-101a-3p and anxiety behaviour, we used a viral approach to overexpress miR-101a-3p in the amygdala of HR rats and test whether it would increase their typically low levels of anxiety-like behaviour. We found that increasing miR-101a-3p in the amygdala increased HRs' anxiety-like behaviour in the open-field test and elevated plus maze. Viral-mediated miR-101a-3p overexpression also reduced expression of the histone methyltransferase Ezh2, which mediates gene silencing via trimethylation of histone 3 at lysine 27 (H3K27me3). Knockdown of Ezh2 with short-interfering RNA (siRNA) also increased HRs' anxiety-like behaviour, but to a lesser degree than miR-101a-3p overexpression. Overall, our data demonstrate that increasing miR-101a-3p expression in the amygdala increases anxiety-like behaviour and that this effect is at least partially mediated via repression of Ezh2. This work adds to the growing body of evidence implicating miRNAs and epigenetic regulation as molecular mediators of anxiety behaviour.