Individual OCD-provoking stimuli activate disorder-related and self-related neuronal networks in fMRI

Negative and positive self-beliefs in social anxiety: The strength of believing mediates the affective response

BACKGROUND AND OBJECTIVES

Current cognitive models of social anxiety disorder (SAD) propose that individual, situation-specific self-beliefs are central to SAD. However, the role of differences in the degree to which individuals with social anxiety are convinced of self-beliefs, in particular positive ones, is still not fully understood. We compared how much high and low socially anxious individuals agree with their own negative and positive self-beliefs. Furthermore, we investigated whether agreeing with one's self-belief can explain the relation between negative affect in response to self-beliefs and social anxiety. Specifically, we were interested whether social anxiety increases negative affect in response to self-beliefs through an increase in agreement.

METHODS

We developed a new experimental self-belief task containing positive and negative semi-idiosyncratic, situation specific self-beliefs typical of high social anxiety and included a direct measure of agreement with these beliefs. Using extreme group sampling, we a-priori selected high (n = 51) and low (n = 50) socially anxious individuals. By multi-level mediation analysis, we analyzed agreement with self-beliefs in both groups and its association with affect.

RESULTS

High and low socially anxious individuals chose similar self-beliefs. However, high socially anxious individuals (HSA) agreed more with negative self-beliefs and less with positive self-beliefs compared to low socially anxious individuals (LSA). HSA individuals reported increased negative affect after both, exposition to negative and positive self-beliefs compared to LSA. We found that social anxiety increases affective responses towards negative-self beliefs through an increase in agreeing with these self-beliefs.

CONCLUSIONS

These findings suggest that cognitive models of social anxiety can be improved by including not only the content of a self-belief but also the strength of such a belief. In addition, they emphasize the relevance of positive self-beliefs in social anxiety, which has frequently been overlooked.

Disgust as a transdiagnostic index of mental illness: A narrative review of clinical populations

Disgust is a basic emotion of rejection, providing an ancestral defensive mechanism against illness. Based on research that documents altered experiences of disgust across several psychopathological conditions, we conducted a narrative review to address the hypothesis that altered disgust may serve as a transdiagnostic index of mental illness. Our synthesis of the literature from past decades suggests that, compared to healthy populations, patients with mental disorders exhibit abnormal processing of disgust in at least one of the analyzed dimensions. We also outline evidence of alterations in brain areas relevant to disgust processing, such as the insula and the interconnected limbic network. Overall, we provide preliminary support for the hypothesis that altered disgust processing may serve as a transdiagnostic index of mental illness.

Symptom provocation in obsessive-compulsive disorder: A voxel-based meta-analysis and meta-analytic connectivity modeling

BACKGROUND

Obsessive-compulsive disorder (OCD) is a heterogeneous psychiatric illness with a complex array of symptoms and potentially distinct neural underpinnings. We employed meta-analysis and connectivity modeling of symptom dimensions to delineate the circuit mechanisms of OCD.

METHODS

With the activation likelihood estimation (ALE) algorithm we performed meta-analysis of whole-brain functional magnetic resonance imaging (fMRI) studies of symptom provocation. We contrasted all OCD patients and controls in a primary analysis and divided the studies according to clinical symptoms in secondary meta-analyses. Finally, we employed meta-analytic connectivity modeling analyses (MACMs) to examine co-activation patterns of the brain regions revealed in the primary meta-analysis.

RESULTS

A total of 14 experiments from 12 eligible studies with a total of 238 OCD patients (124 men) and 219 healthy controls (120 men) were included in the primary analysis. OCD patients showed higher activation in the right caudate body/putamen/insula and lower activation in the left orbitofrontal cortex (OFC), left inferior frontal gyrus (IFG), left caudate body/middle cingulate cortex (MCC), right middle temporal gyrus (MTG), middle occipital gyrus (MOG) and right lateral occipital gyrus (LOG). MACMs revealed significant co-activation between left IFG and left caudate body/MCC, left MOG and right LOG, right LOG and MTG. In the secondary meta-analyses, the washing subgroup showed higher activation in the right OFC, bilateral ACC, left MOG and right caudate body.

CONCLUSION

OCD patients showed elevated dorsal striatal activation during symptom provocation. In contrast, the washing subgroup engaged higher activation in frontal, temporal and posterior cortical structures as well as right caudate body. Broadly consistent with the proposition of cortico-striatal-thalamic-cortical circuit dysfunction, these findings highlight potentially distinct neural circuits that may underlie the symptoms and potentially etiological subtypes of OCD.

Abnormal Fractional Amplitude of Low-Frequency Fluctuation as a Potential Imaging Biomarker for First-Episode Major Depressive Disorder: A Resting-State fMRI Study and Support Vector Machine Analysis

Objective: Major depressive disorder (MDD) is a psychiatric disorder with serious negative health outcomes; however, there is no reliable method of diagnosis. This study explored the clinical diagnostic value of the fractional amplitude of low-frequency fluctuation (fALFF) based on the support vector machine (SVM) method for the diagnosis of MDD.

Methods: A total of 198 first-episode MDD patients and 234 healthy controls were involved in this study, and all participants underwent resting-state functional magnetic resonance imaging (fMRI) scanning. Imaging data were analyzed with the fALFF and SVM methods.

Results: Compared with the healthy controls, the first-episode MDD patients showed higher fALFF in the left mid cingulum, right precuneus, and left superior frontal gyrus (SFG). The increased fALFF in these three brain regions was positively correlated with the executive control reaction time (ECRT), and the increased fALFF in the left mid cingulum and left SFG was positively correlated with the 17-item Hamilton Rating Scale for Depression (HRSD-17) scores. The SVM results showed that increased fALFF in the left mid cingulum, right precuneus, and left SFG exhibited high diagnostic accuracy of 72.92% (315/432), 71.76% (310/432), and 73.84% (319/432), respectively. The highest diagnostic accuracy of 76.39% (330/432) was demonstrated for the combination of increased fALFF in the right precuneus and left SFG, along with a sensitivity of 84.34% (167/198), and a specificity of 70.51% (165/234).

Conclusion: Increased fALFF in the left mid cingulum, right precuneus, and left SFG may serve as a neuroimaging marker for first-episode MDD. The use of the increased fALFF in the right precuneus and left SFG in combination showed the best diagnostic value.

Decreased left amygdala functional connectivity by cognitive-coping therapy in obsessive-compulsive disorder

It is of great clinical importance to explore more efficacious treatments for OCD. Recently, cognitive-coping therapy (CCT), mainly focusing on recognizing and coping with a fear of negative events, has been reported as an efficacious psychotherapy. However, the underlying neurophysiological mechanism remains unknown. This study of 79 OCD patients collected Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and resting-state functional magnetic resonance imaging (rs-fMRI) scans before and after four weeks of CCT, pharmacotherapy plus CCT (pCCT), or pharmacotherapy. Amygdala seed-based functional connectivity (FC) analysis was performed. Compared post- to pretreatment, pCCT-treated patients showed decreased left amygdala (LA) FC with the right anterior cingulate gyrus (cluster 1) and with the left paracentral lobule/the parietal lobe (cluster 2), while CCT-treated patients showed decreased LA-FC with the left middle occipital gyrus/the left superior parietal/left inferior parietal (cluster 3). The z-values of LA-FC with the three clusters were significantly lower after pCCT or CCT than pretreatment in comparisons of covert vs. overt and of non-remission vs. remission patients, except the z-value of cluster 2 in covert OCD. CCT and pCCT significantly reduced the Y-BOCS score. The reduction in the Y-BOCS score was positively correlated with the z-value of cluster 1. Our findings demonstrate that both pCCT and CCT with large effect sizes lowered LA-FC, indicating that FCs were involved in OCD. Additionally, decreased LA-FC with the anterior cingulate cortex (ACC) or paracentral/parietal cortex may be a marker for pCCT response or a marker for distinguishing OCD subtypes. Decreased LA-FC with the parietal region may be a common pathway of pCCT and CCT. Trial registration: ChiCTR-IPC-15005969.

Diagnosis of obsessive-compulsive disorder via spatial similarity-aware learning and fused deep polynomial network

Obsessive-compulsive disorder (OCD) is a type of hereditary mental illness, which seriously affect the normal life of the patients. Sparse learning has been widely used in detecting brain diseases objectively by removing redundant information and retaining monitor valuable biological characteristics from the brain functional connectivity network (BFCN). However, most existing methods ignore the relationship between brain regions in each subject. To solve this problem, this paper proposes a spatial similarity-aware learning (SSL) model to build BFCNs. Specifically, we embrace the spatial relationship between adjacent or bilaterally symmetric brain regions via a smoothing regularization term in the model. We develop a novel fused deep polynomial network (FDPN) model to further learn the powerful information and attempt to solve the problem of curse of dimensionality using BFCN features. In the FDPN model, we stack a multi-layer deep polynomial network (DPN) and integrate the features from multiple output layers via the weighting mechanism. In this way, the FDPN method not only can identify the high-level informative features of BFCN but also can solve the problem of curse of dimensionality. A novel framework is proposed to detect OCD and unaffected first-degree relatives (UFDRs), which combines deep learning and traditional machine learning methods. We validate our algorithm in the resting-state functional magnetic resonance imaging (rs-fMRI) dataset collected by the local hospital and achieve promising performance.

Disrupted functional connectivity of precuneus subregions in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a chronic and disablingpsychiatric disorder with high lifetime prevalence, yet the underlying pathogenesis remains not fully understood. Increasing neuroimaging evidence has shown that the disrupted activity of brain functional hubs might contribute to the pathophysiology of OCD. Precuneus is an important brain hub which showed structural and functional abnormalities in OCD patients. However, the functional heterogeneity of the precuneus subregion has not been considered and its relation to OCD symptomatology remains to be elucidated. In this paper, a total of 73 unmedicated OCD patients and 79 matched healthy subjects were recruited and the heterogeneous functional connectivities (FCs) of the precuneus subregions were investigated using resting-state functional magnetic resonance imaging. The FC-based subdivision of the precuneus was performed using the K-means clustering algorithm, which led to a tripartite functional parcellation of precuneus. For each subregion, the distinct connectivity pattern with the whole brain was shown, using both voxel-wise and module-wise analysis, respectively. Decreased FC between dorsal posterior precuneus and vermis (corrected p<0.01) was shown in the patient group, which was negatively correlated with patient compulsions score (ρ = - 0.393, p = 0.001), indicating its contribution to the compulsive behavior inhibition of OCD. Our work might provide new insights into the understanding of precuneus subregion function and the importance of dorsal precuneus-cerebellum functional connectivity in OCD pathophysiology.

Multi-level assessment of obsessive-compulsive disorder (OCD) reveals relations between neural and neurochemical levels

BACKGROUND

While considerable progress has been made in exploring the psychological, the neural, and the neurochemical dimensions of OCD separately, their interplay is still an open question, especially their changes during psychotherapy.

METHODS

Seventeen patients were assessed at these three levels by psychological questionnaires, fMRI, and venipuncture before and after inpatient psychotherapy. Seventeen controls were scanned at comparable time intervals. First, pre/post treatment changes were investigated for all three levels separately: symptom severity, whole-brain and regional activity, and the concentrations of cortisol, serotonin, dopamine, brain-derived neurotrophic factor (BDNF), and immunological parameters (IL-6, IL-10, TNFα). Second, stepwise linear modeling was used to find relations between the variables of the levels.

RESULTS

The obsessive-compulsive, depressive, and overall symptom severity was significantly reduced after psychotherapy. At the neural level, the activity in the anterior cingulate cortex (ACC), in frontal regions, in the precuneus, and in the putamen had significantly decreased. No significant changes were found on the neurochemical level. When connecting the levels, a highly significant model was found that explains the decrease in neural activity of the putamen by increases of the concentrations of cortisol, IL-6, and dopamine.

CONCLUSION

Multivariate approaches offer insight on the influences that the different levels of the psychiatric disorder OCD have on each other. More research and adapted models are needed.

Erroneously Disgusted: fMRI Study Supports Disgust-Related Neural Reuse in Obsessive-Compulsive Disorder (OCD)

Objective: fMRI scans of patients with obsessive-compulsive disorder (OCD) consistently show a hyperactivity of the insular cortex, a region responsible for disgust-processing, when confronted with symptom-triggering stimuli. This asks for an investigation of the role of disgust and the insula in OCD patients.

Methods: Seventeen inpatients with OCD and 17 healthy controls (HC) underwent fMRI scanning. Whole-brain contrasts were calculated for “Disgust vs. Neutral” for both groups, plus an analysis of variance (ANOVA) to assess the interaction between group and condition. Additionally, the emotional dimensions of valence and arousal, along with the ability to cope, were assessed by picture ratings.

Results: The picture ratings confirmed the patients’ heightened sensitivity to disgust with higher values for arousal and inability to cope, but not for valence. fMRI scans revealed no hyperactivity of the insula in patients compared to controls for the condition “Disgust vs. Neutral,” indicating no basic hypersensitivity to disgusting stimuli. Increased activity in the precuneus in controls for this condition might correspond to the downregulation of arousal.

Conclusions: The absent differences in neural activity of the insula in patients compared to controls for the disgust-condition, but heightened activity for symptom-provoking conditions, suggests that the illness is due to an erroneous recruitment of the insula cortex for OCD-stimuli. The finding is interpreted within the framework of the neural reuse hypothesis.

Compulsivity in Alcohol Use Disorder and Obsessive Compulsive Disorder: Implications for Neuromodulation

Alcohol use Disorder (AUD) is one of the leading causes of morbidity and mortality worldwide. The progression of the disorder is associated with the development of compulsive alcohol use, which in turn contributes to the high relapse rate and poor longer term functioning reported in most patients, even with treatment. While the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) defines AUD by a cluster of symptoms, parsing its heterogeneous phenotype by domains of behavior such as compulsivity may be a critical step to improve outcomes of this condition. Still, neurobiological underpinnings of compulsivity need to be fully elucidated in AUD in order to better design targeted treatment strategies. In this manuscript, we review and discuss findings supporting common mechanisms between AUD and OCD, dissecting the construct of compulsivity and focusing specifically on characteristic disruptions in habit learning and cognitive control in the two disorders. Finally, neuromodulatory interventions are proposed as a probe to test compulsivity as key pathophysiologic feature of AUD, and as a potential therapy for the subgroup of individuals with compulsive alcohol use, i.e., the more resistant stage of the disorder. This transdiagnostic approach may help to destigmatize the disorder, and suggest potential treatment targets across different conditions.