Brain activation to task-irrelevant disorder-related threat in social anxiety disorder: The impact of symptom severity

Neural circuit basis of pathological anxiety

Anxiety disorders are the most prevalent mental health conditions worldwide. Unfortunately, the understanding of the precise neurobiological mechanisms that underlie these disorders remains limited. Current diagnostic classifications, based on observable symptoms rather than underlying pathophysiology, do not capture the heterogeneity within and across anxiety disorders. Recent advances in functional neuroimaging have provided new insights into the neural circuits implicated in pathological anxiety, revealing dysfunctions that cut across traditional diagnostic boundaries. In this Review, we synthesize evidence that highlights abnormalities in neurobehavioural systems related to negative valence, positive valence, cognitive systems and social processes. We emphasize that pathological anxiety arises not only from heightened reactivity in acute threat ('fear') circuits but also from alterations in circuits that mediate distant (potential) and sustained threat, reward processing, cognitive control and social processing. We discuss how circuit vulnerabilities can lead to the emergence and maintenance of pathological anxiety. Once established, these neural abnormalities can be exacerbated by maladaptive behaviours that prevent extinction learning and perpetuate anxiety disorders. By delineating the specific neural mechanisms in each neurobiological system, we aim to contribute to a more comprehensive understanding of the neurobiology of anxiety disorders, potentially informing future research directions in this field.

Event-related potentials of social comparisons in depression and social anxiety

Social comparison is central in human life and can be especially challenging in depression and social anxiety. We assessed event-related potentials and emotions using a social comparison task in which participants received feedback on both their own and a co-player's performance, in participants with depression and/or social anxiety (n = 63) and healthy controls (n = 72). Participants reported more negative emotions for downward (being better than the co-player [participant correct, co-player wrong]) and upward (being worse than the co-player [participant wrong, co-player correct]) comparisons versus even outcomes, with these effects being stronger in depression and social anxiety. At the Medial Frontal Negativity, both controls and depressed participants showed a more negative amplitude for upward comparison versus both the participant and co-player performing wrong. Socially anxious subjects showed the opposite effect, possibly due to greater expectations about being worse than others. The P300 decreased for downward and upward comparisons compared to even outcomes, which may relate to the higher levels of conflict of social inequality. Depressed and socially anxious subjects showed a blunted P300 increase over time in response to the task outcomes, suggesting deficits in allocating resources for the attention of incoming social information. The LPP showed increased amplitude for downward and upward comparison versus the even outcomes and no group effect. Emotional findings suggest that social comparisons are more difficult for depressed and socially anxious individuals. Event-related potentials findings may shed light on the neural substrates of these difficulties.

Shared and distinctive dysconnectivity patterns underlying pure generalized anxiety disorder (GAD) and comorbid GAD and depressive symptoms

The resting-state connectivity features underlying pure generalized anxiety disorder (GAD, G1) and comorbid GAD and depressive symptoms (G2) have not been directly compared. Furthermore, it is unclear whether these features might serve as potential prognostic biomarkers and change with treatment. Degree centrality (DC) in G1 (40 subjects), G2 (58 subjects), and healthy controls (HCs, 54 subjects) was compared before treatment, and the DC of G1 or G2 at baseline was compared with that after 4 weeks of paroxetine treatment. Using support vector regression (SVR), voxel-wise DC across the entire brain and abnormal DC at baseline were employed to predict treatment response. At baseline, G1 and G2 exhibited lower DC in the left mid-cingulate cortex and vermis IV/V compared to HCs. Additionally, compared to HCs, G1 had lower DC in the left middle temporal gyrus, while G2 showed higher DC in the right inferior temporal/fusiform gyrus. However, there was no significant difference in DC between G1 and G2. The SVR based on abnormal DC at baseline could successfully predict treatment response in responders in G2 or in G1 and G2. Notably, the predictive performance based on abnormal DC at baseline surpassed that based on DC across the entire brain. After treatment, G2 responders showed lower DC in the right medial orbital frontal gyrus, while no change in DC was identified in G1 responders. The G1 and G2 showed common and distinct dysconnectivity patterns and they could potentially serve as prognostic biomarkers. Furthermore, DC in patients with GAD could change with treatment.

Cognitive Avoidance Is Associated with Decreased Brain Responsiveness to Threat Distractors under High Perceptual Load

Cognitive coping strategies to deal with anxiety-provoking events have an impact on mental and physical health. Dispositional vigilance is characterized by an increased analysis of the threatening environment, whereas cognitive avoidance comprises strategies to inhibit threat processing. To date, functional neuroimaging studies on the neural underpinnings of these coping styles are scarce and have revealed discrepant findings. In the present study, we examined automatic brain responsiveness as a function of coping styles using functional magnetic resonance imaging. We administered a perceptual load paradigm with contemptuous and fearful faces as distractor stimuli in a sample of N = 43 healthy participants. The Mainz Coping Inventory was used to assess cognitive avoidance and vigilance. An association of cognitive avoidance with reduced contempt and fear processing under high perceptual load was observed in a widespread network including the amygdala, thalamus, cingulate gyrus, insula, and frontal, parietal, temporal, and occipital areas. Our findings indicate that the dispositional tendency to divert one's attention away from distressing stimuli is a valuable predictor of diminished automatic neural responses to threat in several cortical and subcortical areas. A reduced processing in brain regions involved in emotion perception and attention might indicate a potential threat resilience associated with cognitive avoidance.

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.

Relationship between Overweight/Obesity and Social Communication in Autism Spectrum Disorder Children: Mediating Effect of Gray Matter Volume

With advances in medical diagnostic technology, the healthy development of children with autism spectrum disorder (ASD) is receiving more and more attention. In this article, the mediating effect of brain gray matter volume (GMV) between overweight/obesity and social communication (SC) was investigated through the analysis of the relationship between overweight/obesity and SC in autism spectrum disorder children. In total, 101 children with ASD aged 3-12 years were recruited from three special educational centers (Yangzhou, China). Overweight/obesity in children with ASD was indicated by their body mass index (BMI); the Social Responsiveness Scale, Second Edition (SRS-2) was used to assess their social interaction ability, and structural Magnetic Resonance Imaging (sMRI) was used to measure GMV. A mediation model was constructed using the Process plug-in to analyze the mediating effect of GMV between overweight/obesity and SC in children with ASD. The results revealed that: overweight/obesity positively correlated with SRS-2 total points (p = 0.01); gray matter volume in the left dorsolateral superior frontal gyrus (Frontal_Sup_L GMV) negatively correlated with SRS-2 total points (p = 0.001); and overweight/obesity negatively correlated with Frontal_Sup_L GMV (p = 0.001). The Frontal_Sup_L GMV played a partial mediating role in the relationship between overweight/obesity and SC, accounting for 36.6% of total effect values. These findings indicate the significant positive correlation between overweight/obesity and SC; GMV in the left dorsolateral superior frontal gyrus plays a mediating role in the relationship between overweight/obesity and SC. The study may provide new evidence toward comprehensively revealing the overweight/obesity and SC relationship.

Comparing the Effectiveness of Brain Structural Imaging, Resting-state fMRI, and Naturalistic fMRI in Recognizing Social Anxiety Disorder in Children and Adolescents

Social anxiety disorder (SAD) is a common anxiety disorder in childhood and adolescence. Studies on SAD in adults have reported both structural and functional aberrancies of the brain at the group level. However, evidence has shown differences in anxiety-related brain abnormalities between adolescents and adults. Since children and adolescents can afford limited scan time, optimizing the scan tasks is essential for SAD research in children and adolescents. Thus, we need to address whether brain structure, resting-state fMRI, and naturalistic imaging enable individualized identification of SAD in children and adolescents, which measurement is more effective, and whether pooling multi-modal features can improve the identification of SAD. We comprehensively addressed these questions by building machine learning models based on parcel-wise brain features. We found that naturalistic fMRI yielded higher classification accuracy (69.17%) than the other modalities and the classification performance showed dependence on the contents of the movie. The classification models also identified contributing brain regions, some of which exhibited correlations with the symptoms scores of SAD. However, pooling brain features from the three modalities did not help enhance the classification accuracy. These results support the application of carefully designed naturalistic imaging in recognizing children and adolescents at risk of SAD.

Relations between lab indices of emotion dysregulation and negative affect reactivity in daily life in two independent studies

BACKGROUND

We investigated the extent to which physiological/biological measures of emotion dysregulation collected in the lab, resting respiratory sinus arrhythmia (RSA) in Study 1 and amygdala activation in response to negative stimuli in Study 2, combined with daily measures of interpersonal stressors predicted negative emotional states in outpatients better than the stressors alone.

METHODS

Participants were adult outpatients with emotional distress disorders (N=30 individuals in Study 1, and N=26 women in Study 2). After completing a laboratory session that collected physiological/biological measures of emotion dysregulation, participants then completed 1-3 weeks of ambulatory assessment during which they reported on interpersonal stressors and negative affective states several times per day.

RESULTS

Laboratory measures of emotion dysregulation were largely unrelated to either momentary or mean levels of daily-life hostility, sadness, and fear in both studies. However, resting RSA significantly moderated the association between day-level interpersonal stressors and momentary fear such that low resting RSA strengthened this association. Similarly, amygdala activation tended to moderate this relationship in the predicted direction.

LIMITATIONS

Both samples were relatively small and focused on only a limited set of diagnoses associated with emotion dysregulation. Only two possible physiological/biological markers of emotion dysregulation were examined.

CONCLUSIONS

The current studies support the collection of physiological/biological data on emotion dysregulation when indexing daily-life emotion dysregulation as the degree of emotional reactivity to stressors in daily life among outpatients with emotional distress disorders.

Inhibitory attentional control under cognitive load in social anxiety: An investigation using a novel dual-task paradigm

Research suggests that socially anxious (SA) individuals exhibit poorer attentional inhibition than their non-anxious (NA) counterparts. Attentional control theory presumes that cognitive load worsens the adverse effects of anxiety on attentional inhibition. However, previous studies examined the effects of cognitive load on attentional inhibition in social anxiety yielded inconsistent results. In this study, cognitive load was manipulated by adding a 1-back (low cognitive load) and 2-back task (high cognitive load) to the emotional antisaccade task, investigating the effects of cognitive load on attentional inhibition in the presence of social evaluative stimuli in SA and NA individuals. Results revealed that cognitive load improved the efficiency but impeded the effectiveness of inhibitory attentional control in SA participants. Under high cognitive load, SA participants made more erroneous saccades for threat-related than nonthreat-related faces while NA participants showed no differences in error rates among different face types. Moreover, regardless of cognitive levels, SA participants had shorter saccade latencies for angry faces than happy and neutral faces. NA participants did not show differences in saccade latencies among different face types. Implications of these findings for understanding the role that cognitive load plays in the processes of attentional control and interventions for social anxiety are discussed.

The long-term associations between parental behaviors, cognitive function and brain activation in adolescence

Parenting behavior has a vital role in the development of the brain and cognitive abilities of offspring throughout childhood and adolescence. While positive and aggressive parenting behavior have been suggested to impact neurobiology in the form of abnormal brain activation in adolescents, little work has investigated the links between parenting behavior and the neurobiological correlates of cognitive performance during this age period. In the current longitudinal fMRI study, associations between parenting behaviors and cognitive performance and brain activation across mid- and late-adolescence were assessed. Observed measures of maternal aggressive and positive behavior were recorded in early adolescence (12 years) and correlated with fMRI activation and in-scanner behavioral scores on the multi-source interference task (MSIT) during mid- (16 years; 95 participants) and late-adolescence (19 years; 75 participants). There was a significant reduction in inhibitory-control-related brain activation in posterior parietal and cingulate cortices as participants transitioned from mid- to late-adolescence. Positive maternal behavior in early-adolescence was associated with lower activation in the left parietal and DLPFC during the MSIT in mid-adolescence, whereas maternal aggressive behavior was associated with longer reaction time to incongruent trials in late-adolescence. The study supports the notion that maternal behavior may influence subsequent neurocognitive development during adolescence.

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.

Attentional Bias for Threat and Anxiety: The Role of Loneliness

Objective: There is literature to suggest that anxious individuals may be lonely. Attentional bias for threat (ABT), a mechanism implicated in the core symptoms of anxiety, has been linked to loneliness in a separate line of work. The primary aim of this study was to examine the role of loneliness in the association between ABT and anxiety. Method: An unselected sample of 260 individuals (196 Female; Mean Age = 22.43) completed measures of loneliness, ABT (a dot probe task), and anxiety. Two possible models of the role of loneliness in the ABT-anxiety link were tested using hierarchical regression analysis: (1) A moderation model (the ABT-anxiety link is moderated by loneliness), and (2) A proxy model (the ABT-anxiety link is better explained by loneliness). Results: In support of the latter model, ABT no longer predicted anxiety after the effects of loneliness had been accounted for. Additionally, ABT was associated with anxiety only when indexed using sadness-related scenes (but not fear-related scenes). Conclusions: Loneliness may be one important source of exaggerated threat appraisals which underpin the association between ABT and anxiety. Different classes of negative stimuli may be differentially sensitive to anxiety and should be a point of consideration in future research.

Association of NPSR1 gene variation and neural activity in patients with panic disorder and agoraphobia and healthy controls

INTRODUCTION

The neurobiological mechanisms behind panic disorder with agoraphobia (PD/AG) are not completely explored. The functional A/T single nucleotide polymorphism (SNP) rs324981 in the neuropeptide S receptor gene (NPSR1) has repeatedly been associated with panic disorder and might partly drive function respectively dysfunction of the neural "fear network". We aimed to investigate whether the NPSR1 T risk allele was associated with malfunctioning in a fronto-limbic network during the anticipation and perception of agoraphobia-specific stimuli.

METHOD

121 patients with PD/AG and 77 healthy controls (HC) underwent functional magnetic resonance imaging (fMRI) using the disorder specific "Westphal-Paradigm". It consists of neutral and agoraphobia-specific pictures, half of the pictures were cued to induce anticipatory anxiety.

RESULTS

Risk allele carriers showed significantly higher amygdala activation during the perception of agoraphobia-specific stimuli than A/A homozygotes. A linear group x genotype interaction during the perception of agoraphobia-specific stimuli showed a strong trend towards significance. Patients with the one or two T alleles displayed the highest and HC with the A/A genotype the lowest activation in the inferior orbitofrontal cortex (iOFC).

DISCUSSION

The study demonstrates an association of the NPSR1rs324981 genotype and the perception of agoraphobia-specific stimuli. These results support the assumption of a fronto-limbic dysfunction as an intermediate phenotype of PD/AG.

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.

Social Feedback Modulates Neural Response Associated With Cognitive Bias in Individuals Expressing Anxious Symptoms

BACKGROUND

Social anxiety is characterized by a tendency to overestimate the likelihood of negative outcomes and consequences before, during, and after interpersonal interactions with social partners. Recent evidence suggests that a network of brain regions critical for perspective-taking, threat appraisal, and uncertainty resolution may function atypically in those prone to social anxiety. In this study, we used functional magnetic resonance imaging to examine neural activity in specific regions of interest in a sample of young adults who endorsed high or low levels of social anxiety.

METHODS

We recruited 31 college student volunteers (age: 18-28 years), categorized as having high or low anxiety based on their Liebowitz Social Anxiety Scale-Self Report scores. These participants were each scanned while playing the iterated Prisoner's Dilemma game with three computerized confederates, two of whom they were deceived to believe were human co-players. This study focuses on data collected during play with the presumed humans. Regions of interest were defined for the temporoparietal junction, anterior midcingulate, and dorsomedial prefrontal cortex. Average weighted mean blood-oxygen-level-dependent signals for each subject were extracted and analyzed using mixed design analyses of variance to detect group differences in activation during decision-making, anticipation, and appraisal of round outcomes during the game.

RESULTS

Behavior analysis revealed that the high-anxiety group was more likely to defect than the low-anxiety group. Neuroimaging analysis showed that the high-anxiety group exhibited elevated blood-oxygen-level-dependent activity relative to the low-anxiety group in all three regions during the social feedback appraisal phase but not during decision-making or the anticipation of interaction outcomes.

CONCLUSIONS

These findings provide evidence that some behaviors linked to cognitive biases associated with social anxiety may be mediated by a network of regions involved in recognizing and processing directed social information. Future investigation of the neural basis of cognition and bias in social anxiety using the prisoner's dilemma and other economic-exchange tasks is warranted. These tasks appear to be highly effective, functional magnetic resonance imaging-compatible methods of probing altered cognition and behavior associated with anxiety and related conditions.

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.

Precuneus-related regional and network functional deficits in social anxiety disorder: A resting-state functional MRI study

BACKGROUND

Neuroimaging findings suggest that social anxiety disorder (SAD) may be correlated with changes in regional- or network-level brain function. However, few studies have explored alterations in intrinsic resting cerebral function in patients with SAD at both the regional and network levels, particularly focusing on the theory of mind (ToM)-related regions. This study was performed to investigate changes in neural activity and functional connectivity (FC) in ToM-related regions during the resting state in SAD patients and to determine how these alterations are correlated with the clinical symptoms of SAD.

METHODS

Forty-three SAD patients and 43 matched healthy controls underwent resting-state functional magnetic resonance imaging (rsfMRI) scans. First, the amplitude of low-frequency fluctuation (ALFF) approach was used to explore regional activity. Then, the ToM-related region, i.e., the left precuneus, which showed altered ALFF values, was adopted as a seed for further FC analyses to assess network-level alterations in SAD. Between-group differences were compared using voxel-based two-sample t-tests (P<0.05, with Gaussian random field correction). Pearson's correlation analyses were performed to examine relationships between alterations in ALFF and FC and clinical symptoms.

RESULTS

Compared with the healthy controls, SAD patients showed decreased ALFF in the bilateral putamen (PUT) and left supplementary motor area (SMA) and increased ALFF in the right inferior parietal lobule (IPL), left precuneus and right cerebellar posterior lobe. Moreover, SAD patients exhibited lower connectivity between the left precuneus and the cerebellar posterior lobe, right inferior temporal gyrus (ITG), right parahippocampal gyrus (PHG) and left medial prefrontal cortex (mPFC). The altered ALFF values in the left precuneus and the hypoconnectivity between the left precuneus and left cerebellar posterior lobe were correlated with the patients' clinical symptoms (P<0.05).

CONCLUSION

The precuneus, a ToM-related region, was altered at both the regional and network level in patients with SAD. Pathological fear and avoidance in SAD were correlated with abnormal regional function in the precuneus, whereas depression and anxiety were primarily correlated with functional deficits in the precuneus-related network. The altered FC within the precuneus-cerebellar region may reflect an imbalance in the neuromodulation of anxiety and depressive symptoms in SAD. These findings may facilitate a greater understanding of potential SAD neural substrates and could be used to identify potential targets for further treatment.

Gray Matter Structural Alterations in Social Anxiety Disorder: A Voxel-Based Meta-Analysis

The current insight into the neurobiological pathogenesis underlying social anxiety disorder (SAD) is still rather limited. We implemented a meta-analysis to explore the neuroanatomical basis of SAD. We undertook a systematic search of studies comparing gray matter volume (GMV) differences between SAD patients and healthy controls (HC) using a whole-brain voxel-based morphometry (VBM) approach. The anisotropic effect size version of seed-based d mapping (AES-SDM) meta-analysis was conducted to explore the GMV differences of SAD patients compared with HC. We included eleven studies with 470 SAD patients and 522 HC in the current meta-analysis. In the main meta-analysis, relative to HC, SAD patients showed larger GMVs in the left precuneus, right middle occipital gyrus (MOG) and supplementary motor area (SMA), as well as smaller GMV in the left putamen. In the subgroup analyses, compared with controls, adult patients (age ≥ 18 years) with SAD exhibited larger GMVs in the left precuneus, right superior frontal gyrus (SFG), angular gyrus, middle temporal gyrus (MTG), MOG and SMA, as well as a smaller GMV in the left thalamus; SAD patients without comorbid depressive disorder exhibited larger GMVs in the left superior parietal gyrus and precuneus, right inferior temporal gyrus, fusiform gyrus, MTG and superior temporal gyrus (STG), as well as a smaller GMV in the bilateral thalami; and currently drug-free patients with SAD exhibited a smaller GMV in the left thalamus compared with HC while no larger GMVs were found. For SAD patients with different clinical features, our study revealed directionally consistent larger cortical GMVs and smaller subcortical GMVs, including locationally consistent larger precuneus and thalamic deficits in the left brain. Age, comorbid depressive disorder and concomitant medication use of the patients might be potential confounders of SAD at the neuroanatomical level.