Social Anxiety Disorder Subjects Research Articles

Complexity Analysis of EEG in Patients With Social Anxiety Disorder Using Fuzzy Entropy and Machine Learning Techniques

The diagnosis of social anxiety disorder (SAD) is of great consequence not only due to its impacts on the individual and society but also the expenditures to the national health systems. There is yet a deficiency of objective neurophysiological information to assist the present clinical SAD diagnosis. The main objective of this study is to analyze the electroencephalogram (EEG) complexity of 88 SAD subjects, subdivided into 4 balanced groups (22 severe, 22 moderate, 22 mild, and 22 healthy controls (HCs) using Fuzzy Entropy measure (FE) and machine learning algorithms. In addition, this study aimed at designing a computer-aided diagnosis system to identify the severity of SAD (severe, moderate, mild, and HC) in different EEG frequency bands (delta, theta, alpha, and beta). The experimental results showed that among the HC and the three considered levels of SAD, SAD patients in fast-waves exhibited significantly less FE values in resting-state compared with HCs (p <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\leq0.05$ </tex-math></inline-formula> ). The EEG complexity analysis showed a discriminatory neuronal activity over the frontoparietal and occipital regions between SAD patients and HCs. Additionally, the FE values measured in the resting-state were positively correlated with Social Interaction Anxiety Scale (SIAS) scores in fast-waves (beta and alpha), indicating that the regional FE measures are putative biomarkers in assessing the clinical symptoms of SAD. Also, the classification results demonstrated that the proposed method outperformed the state of the art methods with an accuracy of 86.93 %, sensitivity of 92.46%, and specificity of 95.32% with the Naive Bayes (NB) classifier. This study emphasizes the viability of quantitative FE measures and the specific combinations involving the chosen classifiers could be considered as an alternative biomarker for future clinical SAD recognition.

Diagnostic and dimensional evaluation of implicit reward learning in social anxiety disorder and major depression.

Increasing evidence supports the presence of an anhedonic endophenotype in major depressive disorder (MDD), characterized by impairments in various components of reward processing, particularly incentive motivation, effort-based decision making, and reward learning. In addition to its prominent role in MDD, reward processing dysregulation has been proposed as a transdiagnostic risk and/or maintenance factor for a range of other forms of psychopathology. Individuals with social anxiety disorder (SAD)-a condition that frequently co-occurs with MDD-demonstrate low trait positive affectivity and altered processing of rewards and positively valenced information. However, no studies to date have directly tested reward learning-the ability to modulate behavior in response to rewards-in this population. The current study evaluated reward learning in MDD, SAD, and healthy control subjects (N = 90) using a well-validated signal detection task. Given increasing data supporting transdiagnostic features of psychopathology, we also evaluated associations between anhedonia and task performance transdiagnostically in the patient sample. Contrary to expectations, results indicated no significant group differences in response bias in the full sample, suggesting no diagnostic differences in reward learning. However, dimensional analyses revealed that higher self-reported anhedonia (but not general distress or anxious arousal) was associated with worse reward learning in both the MDD and SAD groups explaining about 11% of the variance. Deficits in implicit reward learning are associated with anhedonia but not necessarily with major depressive disorder as a diagnosis, which supports the use of transdiagnostic approaches to understanding psychopathology.

Cortical activity during social acceptance and rejection task in social anxiety disorder: A controlled functional near infrared spectroscopy study

BackgroundThe cognitive and emotional vulnerability of individuals with social anxiety disorder (SAD) and their response to repeated experiences of social rejection and social acceptance are important factors for the emergence and maintenance of symptoms of the disorder. Functional neuroimaging studies of SAD reveal hyperactivity in regions involved in the fear circuit such as amygdala, insula, anterior cingulate, and prefrontal cortices (PFC) in response to human faces with negative emotions. Observation of brain activity, however, involving studies of responses to standardized human interaction of social acceptance and social rejection have been lacking. MethodsWe compared a group of index subjects with SAD (N = 22, mean age:26.3 ± 5.4, female/male: 7/15) (SADG) with a group of healthy controls (CG) (N = 21, mean age:28.7 ± 4.5, female/male: 14/7) in measures of cortical activity during standardized experiences of human interaction involving social acceptance (SA) and social rejection (SR) video-simulated handshaking tasks performed by real actors. In a third, control condition (CC), the subjects were expected to press a switch button in an equivalent space. Subjects with a concurrent mood episode were excluded and the severity of subclinical depressive symptoms was controlled. 52-channel functional near-infrared spectroscopy (fNIRS) was used to measure cortical activity. ResultsActivity was higher in the SAD subjects compared to healthy controls, in particular in channels that project to middle and superior temporal gyri (STG), frontal eye fields (FEF) and dorsolateral prefrontal cortex (DLPFC) in terms of both SA and SR conditions. Cortical activity during the CC was not different between the groups. Only in the SAD-group, activity in the pre-motor and supplementary motor cortices, inferior and middle temporal gyri and fronto-polar area was higher during the rejection condition than the other two conditions. Anxiety scores were correlated with activity in STG, DLPFC, FEF and premotor cortex, while avoidance scores were correlated with activity in STG and FEF. ConclusionsSA and SR are represented differently in terms of cortical activity in SAD subjects compared to healthy controls. Higher activity in both social conditions in SAD subjects compared to controls may imply biological sensitivity to these experiences and may underscore the importance of increased cortical activity during social interaction experiences as a putative mediator of vulnerability to SAD. Higher cortical activity in the SADG may possibly indicate stronger need for inhibitory control mechanisms and higher recruitment of theory of mind functions during social stress. Higher activity during the SR compared to the SA condition in the SAD subjects may also suggest distinct processing of social cues, whether they involve acceptance or rejection.

The characteristics of the comorbidity between social anxiety and separation anxiety disorders in adult patients

Objective: In the present study, we compared social anxiety disorder (SAD) patients with (n = 31) and without childhood and adulthood separation anxiety disorder (SeAD) (n = 50) with respect to suicidal behavior, avoidant personality disorder (AvPD), other anxiety disorders (ADs), and major depression as well as some sociodemographic variables.Methods: In assessment of patients, we used Structured Clinical Interview for Separation Anxiety Symptoms, childhood and adulthood Separation Anxiety Symptom Inventories, Liebowitz Social Anxiety Scale, The SCID-II Avoidant Personality Disorder Module, Beck Depression Inventory, and Beck Scale for Suicidal Ideation.Results: SAD patients with SeAD had higher comorbidity rates of AvPD, other lifetime ADs and panic disorder, and current major depression than those without SeAD. The current scores of SAD, depression, and suicide ideation and the mean number of AvPD symptoms were significantly higher in comorbid group compared to pure SAD subjects. The SAD and SeAD scores had significant associations with current depression, suicide ideations, and AvPD. The mean number of AvPD criteria and the current severity of depression were significantly associated with the comorbidity between SAD and SeAD.Conclusion: Our findings might indicate that the comorbidity of SeAD with SAD may increase the risk of the severity of AvPD and current depression.

Standard of proof and intolerance of uncertainty in obsessive-compulsive disorder and social anxiety disorder

Background and objectivesResearchers have identified intolerance of uncertainty (IU) as a dysfunctional thought that contributes to OCD. Case examples of OCD suggest that uncertainty and anxiety persist despite low likelihoods of feared outcomes. In this study we examined how people with OCD react to minimal amounts of uncertainty relative to non-anxious individuals and a clinical comparison group of people with social anxiety disorder (SAD). MethodsWe created a questionnaire to measure the distress people feel when there is only minimal uncertainty regarding a given outcome and if they prefer situations with the certainty of negative outcomes in the present versus living with uncertainty. Part two of our study tested whether IU is related to performance on neutral and idiographic versions of the Beads Task. ResultsOCD and SAD subjects reacted to hypothetical scenarios involving minimal risk with greater negative affect than did non-anxious subjects; however, after repeating analyses to account for comorbid disorders, OCD subjects’ scores did not differ from those of non-anxious subjects. Only SAD subjects showed a preference for negative information in the present versus the uncertainty of a future outcome. Part two of our study revealed that self-reported IU was only marginally associated with performance on the neutral Beads Task. LimitationsHigh rates of comorbidity made it difficult to identify the specific relationship of IU with other anxiety disorders. ConclusionsIU for general, non-OCD specific scenarios may not figure prominently in all individuals with OCD, but rather may play a larger, more consistent role in anxiety disorders such as SAD. Additionally, the number of beads or words viewed on Beads Task may be an inadequate behavioral measure of IU.

The relationship between social anxiety, shyness and blushing

The diagnosis of social anxiety disorder (SAD) has seen substantial changes in the last 35 years from its first appearance in the DSM-III in 1980 up to the most recent ones in the DSM-5. Throughout all these changes, this disorder, previously called social phobia, is still considered one homogenous entity with only one specifier (“performance only”) introduced in the DSM-5 revision with specific fears or associated personality profiles not being considered relevant clinical markers to define SAD subtypes. However, our therapeutic experience suggested substantial particularities associated with the fear of blushing in patients with SAD. Some patients presenting this profile, historically called “erythrophobia”, seem to have a very specific type of social anxiety that does not include shyness and other characteristics of classical SAD. In a study conducted in a sample of 450 new consecutive outpatients seeking treatment for SAD, we compared 142 subjects with fear of blushing without other social fears, 97 subjects with fear of blushing with other associated social fears and 190 SAD subjects without fear of blushing. The group with pure fear of blushing presented a different profile when compared with the two other groups: later age of onset, less comorbidity, lower behavioral and temperamental inhibition, i.e. less shyness, and higher self-esteem. Furthermore, from a therapeutic point of view, some specific strategies such as the Task Concentration Training have shown to be particularly effective in fear of blushing. We will further argue the validity of a possible “fear of blushing” subtype of SAD.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Gray Matter Abnormalities in Social Anxiety Disorder: Primary, Replication, and Specificity Studies

Despite increasing evidence that neuroanatomical abnormalities underlie pathological anxiety, social anxiety disorder (SAD)-although among the most common of anxiety disorders-has received little attention. With magnetic resonance imaging, we: 1) examined gray matter (GM) differences between generalized SAD and healthy control groups; 2) retested the findings in an independent clinical sample; and 3) tested for specificity by contrasting the SAD group to a separate group of panic disorder (PD) subjects. The primary SAD group (n = 16) was required to meet DSM-IV criteria for SAD, with onset by age 30 years; control subjects (n = 20) had no lifetime history of anxiety. The replication sample included 17 generalized SAD and 17 control subjects. The PD comparison group (n = 16) was required to have no lifetime SAD. Images were acquired on a 1.5-Tesla GE Signa magnetic resonance imaging scanner with a three-dimensional T1-weighted spoiled gradient recalled pulse sequence. Morphological differences were determined with voxel-based morphometry, in SPM8. After adjusting for age, gender, and total intracranial volume, SAD (as compared with control) subjects had greater GM in the left parahippocampal and middle occipital, and bilateral supramarginal and angular cortices, and left cerebellum; and lower GM in bilateral temporal poles and left lateral orbitofrontal cortex. Cerebellar, parahippocampal, and temporal pole differences were observed in both samples, survived whole brain corrections, and were not observed in the PD group, pointing to relative specificity to SAD. These findings parallel the functional literature on SAD and suggest structural abnormalities underlying the functional disturbances.

Comparison of neuropsychological functioning and emotional processing in major depression and social anxiety disorder subjects, and matched healthy controls

Few studies of neuropsychological function in major depression have examined emotional processing or the impact of gender. Patients have also been compared with highly selected control participants and rarely with other patient groups. The objective of this study was to compare neuropsychological function in a major depressive episode (MDE) with a group of patients with an anxiety disorder, social anxiety disorder (SAD), and healthy controls, to include measures of emotional processing and to analyse the effects of gender on neuropsychological function and emotional processing in these groups. One hundred and one medication-free patients with MDE, 30 patients with SAD and 76 healthy control participants were recruited. The groups were matched for age and estimated premorbid intelligence and education. Subjects performed a battery of neuropsychological tests assessing; verbal learning and memory, visuospatial learning and memory, attention, executive function and psychomotor performance. They also performed a task measuring the accuracy of recognition of facial emotional expressions. Compared with healthy participants and those with SAD, patients with MDE were significantly impaired in verbal learning and spatial working memory. The SAD group misclassified significantly more neutral expressions as angry and fewer as sad, compared with the MDE group and healthy controls, but there were no significant differences between the MDE group and healthy controls. The profile of performance was the same regardless of gender. The study confirms a significant impairment in neuropsychological function in a clinical sample of outpatients with MDE, which is likely to have important implications for day-to-day functioning and treatment.

The natural course of social anxiety disorder among adolescents and young adults

To examine the natural course of social anxiety disorder (SAD) in the community and to explore predictors for adverse long-term outcomes. A community sample of N = 3021 subjects aged 14-24 was followed-up over 10 years using the DSM-IV/M-CIDI. Persistence of SAD is based on a composite score reflecting the proportion of years affected since onset. Diagnostic stability is the proportion of SAD subjects still affected at follow-up. SAD reveals considerable persistence with more than half of the years observed since onset spent with symptoms. 56.7% of SAD cases revealed stability with at least symptomatic expressions at follow-up; 15.5% met SAD threshold criteria again. 15.1% were completely remitted (no SAD symptoms and no other mental disorders during follow-up). Several clinical features (early onset, generalized subtype, more anxiety cognitions, severe avoidance and impairment, co-occurring panic) and vulnerability characteristics (parental SAD and depression, behavioural inhibition, harm avoidance) predicted higher SAD persistence and - less impressively - diagnostic stability. A persistent course with a considerable degree of fluctuations in symptom severity is characteristic for SAD. Both consistently meeting full threshold diagnostic criteria and complete remissions are rare. Vulnerability and clinical severity indicators predict poor prognosis and might be helpful markers for intervention needs.

Neural circuitry of submissive behavior in social anxiety disorder: A preliminary study of response to direct eye gaze

Fear of eye gaze is common in social anxiety disorder (SAD) and may represent an evolutionarily conserved submissive behavior. SAD subjects and healthy volunteers who underwent functional magnetic resonance imaging showed significant differences in neural activity in amygdala, fusiform, insula, anterior cingulate and prefrontal cortex in response to direct versus averted gaze. Neural response to direct gaze may identify brain regions important in the pathophysiology of SAD.

Gray's BIS/BAS dimensions in non-comorbid, non-medicated social anxiety disorder

Gray's behavioural inhibition and behavioural activation (BIS/BAS) neural systems model has led to research on approach and withdrawal as the two most fundamental dimensions of affective behaviour, and their role in psychopathology. Although Gray proposed the BIS as the neurological basis of anxiety, there are no reports examining approach and withdrawal predispositions in social anxiety disorder. Here we report approach and withdrawal predispositions in a group of 23 non-medicated individuals with social anxiety disorder (SAD) without co-morbid depression and in 48 normal controls. Results show increased BIS and decreased BAS fun-seeking in SAD subjects thereby underscoring Gray's dimensional model.

Resting brain perfusion in social anxiety disorder: A voxel-wise whole brain comparison with healthy control subjects

Introduction Social anxiety disorder (SAD) is a condition characterised by fears of social interaction and performance situations. SAD may be related to a dysregulation or hyperactivity of cortico-limbic circuitry. This is the first voxel-based whole brain study comparing resting function in SAD to a normal control group. Methods Resting perfusion in adult subjects with generalised SAD was compared with healthy adult volunteers using Statistical Parametric Mapping (SPM). In subjects with SAD, correlations were also sought between resting perfusion and clinical severity measured using the total Liebowitz Social Anxiety Scale (LSAS). Results Twenty-eight subjects with SAD were compared with 19 healthy volunteers. SAD subjects had increased resting perfusion in the frontal cortex and right cerebellum, and decreased perfusion in the pons, left cerebellum, and right precuneus. Total LSAS correlated positively with left frontal cortex resting perfusion, and negatively with right fusiform and right lingual perfusion. Conclusion This study demonstrated increased resting frontal function in social anxiety disorder that is consistent with its hypothesised role in the modulation of excessive limbic activity in anxiety disorders. The correlation of posterior cortical resting function with the severity of SAD symptoms may point to defective perception of self and others.

High-field MRS study of GABA, glutamate and glutamine in social anxiety disorder: Response to treatment with levetiracetam

Objective Abnormalities in brain gamma-aminobutyric acid (GABA) and glutamate may be relevant to the underlying pathophysiology of anxiety disorders including social anxiety disorder (SAD). Methods We used proton magnetic resonance spectroscopy (pMRS) to examine whole brain and regional GABA, glutamate and glutamine in patients ( N = 10) with SAD at baseline compared to a matched group of healthy controls (HC), and changes following 8 weeks of pharmacotherapy with levetiracetam. Results For SAD subjects, there were significantly higher whole brain levels of glutamate and glutamine, though no significant differences in GABA. In the thalamus, glutamine was higher and GABA lower for SAD subjects. There was a significant reduction in thalamic glutamine with levetiracetam treatment. Conclusion Our findings provide preliminary support for impaired GABAergic and overactive glutamatergic function in social anxiety disorder and the potential relevance of changes in these systems for the anxiolytic response to levetiracetam.