Emotional Processing in Obsessive-Compulsive Disorder: A Systematic Review and Meta-analysis of 25 Functional Neuroimaging Studies

Psilocybin in pharmacotherapy of obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a chronic mental disease that affects approximately 2% of the population. Obsessions and compulsions are troublesome for patients and may disturb their everyday activities. The pathogenesis of this disease is still not fully elucidated, but dysfunctions of serotonin-, dopamine- and glutamate-mediated neurotransmission together with early maladaptive schemas seem of importance. Pharmacological treatment includes drugs affecting the serotoninergic, dopaminergic, and glutamatergic systems, such as selective serotonin reuptake inhibitors (SSRIs). Providing that up to 40% of patients with OCD are resistant to the currently available medications, there is a need for novel and effective therapies. Recent discoveries suggest that psilocybin, a non-physically addictive psychoactive substance, may ameliorate disease symptoms. When used in appropriate doses and under strict clinical control, psilocybin appears as a valuable treatment for OCD. This narrative article provides a thorough overview of OCD's etiology, current treatment options, and the emerging evidence supporting psilocybin's efficacy in managing OCD symptoms.

Symptom provocation in obsessive-compulsive disorder: Validation of the Braga Obsessive Compulsive image set (BOCIS)

Symptom provocation paradigms are paramount to understand a heterogeneous disorder as obsessive-compulsive disorder (OCD). The main aim of our work was to develop and validate an open-access set of OCD-related images comprising three main subtypes: washing, checking, and symmetry. Twenty-six OCD patients and 25 controls provided valence and arousal ratings for a set of OCD-related, aversive, and neutral images. Linear mixed model analyses were used to estimate the main effects of group, image category, and group-image category interaction in image ratings. All main effects were found to be significant for both arousal and valence ratings, except for the group in arousal ratings. Path analysis confirmed our hypothesis that the OCI-R subscales influenced the subjective ratings of the corresponding image categories, particularly among patients. Independent samples t-tests were performed for each OCD picture to compose the set. Arousal demonstrated a greater capacity to distinguish controls and patients, thus sustaining our choice of using these ratings for the final Braga Obsessive-Compulsive Image Set (BOCIS). Our study demonstrated that the stimuli of the BOCIS reliably portray OCD-like triggers for washing, checking and symmetry subtypes. Its open-access availability will facilitate significant progress in both clinical and research settings.

A three-dimensional model of neural activity and phenomenal-behavioral patterns

How phenomenal experience and behavior are related to neural activity in physiology and psychopathology represents a fundamental question in neuroscience and psychiatry. The phenomenal-behavior patterns may be deconstructed into basic dimensions, i.e., psychomotricity, affectivity, and thought, which might have distinct neural correlates. This work provides a data overview on the relationship of these phenomenal-behavioral dimensions with brain activity across physiological and pathological conditions (including major depressive disorder, bipolar disorder, schizophrenia, attention-deficit/hyperactivity disorder, anxiety disorders, addictive disorders, Parkinson's disease, Tourette syndrome, Alzheimer's disease, and frontotemporal dementia). Accordingly, we propose a three-dimensional model of neural activity and phenomenal-behavioral patterns. In this model, neural activity is organized into distinct units in accordance with connectivity patterns and related input/output processing, manifesting in the different phenomenal-behavioral dimensions. (1) An external neural unit, which involves the sensorimotor circuit/brain's sensorimotor network and is connected with the external environment, processes external inputs/outputs, manifesting in the psychomotor dimension (processing of exteroception/somatomotor activity). External unit hyperactivity manifests in psychomotor excitation (hyperactivity/hyperkinesia/catatonia), while external unit hypoactivity manifests in psychomotor inhibition (retardation/hypokinesia/catatonia). (2) An internal neural unit, which involves the interoceptive-autonomic circuit/brain's salience network and is connected with the internal/body environment, processes internal inputs/outputs, manifesting in the affective dimension (processing of interoception/autonomic activity). Internal unit hyperactivity manifests in affective excitation (anxiety/dysphoria-euphoria/panic), while internal unit hypoactivity manifests in affective inhibition (anhedonia/apathy/depersonalization). (3) An associative neural unit, which involves the brain's associative areas/default-mode network and is connected with the external/internal units (but not with the environment), processes associative inputs/outputs, manifesting in the thought dimension (processing of ideas). Associative unit hyperactivity manifests in thought excitation (mind-wandering/repetitive thinking/psychosis), while associative unit hypoactivity manifests in thought inhibition (inattention/cognitive deficit/consciousness loss). Finally, these neural units interplay and dynamically combine into various neural states, resulting in the complex phenomenal experience and behavior across physiology and neuropsychiatric disorders.

The cognitive neuroscience of self-awareness: Current framework, clinical implications, and future research directions

Self-awareness, the ability to take oneself as the object of awareness, has been an enigma for our species, with different answers to this question being provided by religion, philosophy, and, more recently, science. The current review aims to discuss the neurocognitive mechanisms underlying self-awareness. The multidimensional nature of self-awareness will be explored, suggesting how it can be thought of as an emergent property observed in different cognitive complexity levels, within a predictive coding approach. A presentation of alterations of self-awareness in neuropsychiatric conditions will ground a discussion on alternative frameworks to understand this phenomenon, in health and psychopathology, with future research directions being indicated to fill current gaps in the literature. This article is categorized under: Philosophy > Consciousness Psychology > Brain Function and Dysfunction Neuroscience > Cognition.

Persistent enhancement of basolateral amygdala-dorsomedial striatum synapses causes compulsive-like behaviors in mice

Compulsive behaviors are observed in a range of psychiatric disorders, however the neural substrates underlying the behaviors are not clearly defined. Here we show that the basolateral amygdala-dorsomedial striatum (BLA-DMS) circuit activation leads to the manifestation of compulsive-like behaviors. We revealed that the BLA neurons projecting to the DMS, mainly onto dopamine D1 receptor-expressing neurons, largely overlap with the neuronal population that responds to aversive predator stress, a widely used anxiogenic stressor. Specific optogenetic activation of the BLA-DMS circuit induced a strong anxiety response followed by compulsive grooming. Furthermore, we developed a mouse model for compulsivity displaying a wide spectrum of compulsive-like behaviors by chronically activating the BLA-DMS circuit. In these mice, persistent molecular changes at the BLA-DMS synapses observed were causally related to the compulsive-like phenotypes. Together, our study demonstrates the involvement of the BLA-DMS circuit in the emergence of enduring compulsive-like behaviors via its persistent synaptic changes.

Identifying emotional components of event-related potentials in the brain functioning of individuals with contamination obsessions and comparison with healthy control group

The present study aimed to examine the emotional components of event-related potentials (ERPs) in individuals with contamination OCD and compare them with a healthy control group. A convenience sample of 45 participants was included, consisting of 30 individuals diagnosed with contamination-type OCD and 15 individuals in a healthy control group. Both groups participated in an ERP study where they encountered a computer-based task presenting both contamination and neutral pictures, while their brain activity was recorded. The data were analyzed using repeated measures analysis of variance (RANOVA) with SPSS-24 and Matlab software. Findings suggest that in P3 amplitude, only individuals with OCD exhibited a larger positive amplitude (p < 0.05) in response to contaminated pictures compared to neutral pictures and in N2 amplitude, only individuals with OCD exhibited a larger negative amplitude (p < 0.05) in response to contaminated pictures compared to neutral pictures in the central vertex (Fz). These findings hold promising implications for the development of more targeted and effective treatments for contamination OCD, emphasizing the importance of emotion-oriented approaches to address the unique neural patterns observed in the frontal vertex.

Insight in obsessive-compulsive disorder: conception, clinical characteristics, neuroimaging, and treatment

Obsessive-compulsive disorder (OCD) is a chronic disabling disease with often unsatisfactory therapeutic outcomes. The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) has broadened the diagnostic criteria for OCD, acknowledging that some OCD patients may lack insight into their symptoms. Previous studies have demonstrated that insight can impact therapeutic efficacy and prognosis, underscoring its importance in the treatment of mental disorders, including OCD. In recent years, there has been a growing interest in understanding the influence of insight on mental disorders, leading to advancements in related research. However, to the best of our knowledge, there is dearth of comprehensive reviews on the topic of insight in OCD. In this review article, we aim to fill this gap by providing a concise overview of the concept of insight and its multifaceted role in clinical characteristics, neuroimaging mechanisms, and treatment for OCD.

Effectiveness of Emotional Processing Therapy on the Anxiety among Obsessive-Compulsive Patients

The Article Abstract is not available.

Mechanisms underlying capsulotomy for refractory obsessive-compulsive disorder: neural correlates of negative affect processing overlap with deep brain stimulation targets

Ablative procedures such as anterior capsulotomy are potentially effective in refractory obsessive-compulsive disorder (OCD). Converging evidence suggests the ventral internal capsule white matter tracts traversing the rostral cingulate and ventrolateral prefrontal cortex and thalamus is the optimal target for clinical efficacy across multiple deep brain stimulation targets for OCD. Here we ask which prefrontal regions and underlying cognitive processes might be implicated in the effects of capsulotomy by using both task fMRI and neuropsychological tests assessing OCD-relevant cognitive mechanisms known to map across prefrontal regions connected to the tracts targeted in capsulotomy. We tested OCD patients at least 6 months post-capsulotomy (n = 27), OCD controls (n = 33) and healthy controls (n = 34). We used a modified aversive monetary incentive delay paradigm with negative imagery and a within session extinction trial. Post-capsulotomy OCD subjects showed improved OCD symptoms, disability and quality of life with no differences in mood or anxiety or cognitive task performance on executive, inhibition, memory and learning tasks. Task fMRI revealed post-capsulotomy decreases in the nucleus accumbens during negative anticipation, and in the left rostral cingulate and left inferior frontal cortex during negative feedback. Post-capsulotomy patients showed attenuated accumbens-rostral cingulate functional connectivity. Rostral cingulate activity mediated capsulotomy improvement on obsessions. These regions overlap with optimal white matter tracts observed across multiple stimulation targets for OCD and might provide insights into further optimizing neuromodulation approaches. Our findings also suggest that aversive processing theoretical mechanisms may link ablative, stimulation and psychological interventions.

Face-Selective Patches in Marmosets Are Involved in Dynamic and Static Facial Expression Processing

The correct identification of facial expressions is critical for understanding the intention of others during social communication in the daily life of all primates. Here we used ultra-high-field fMRI at 9.4 T to investigate the neural network activated by facial expressions in awake New World common marmosets from both male and female sex, and to determine the effect of facial motions on this network. We further explored how the face-patch network is involved in the processing of facial expressions. Our results show that dynamic and static facial expressions activate face patches in temporal and frontal areas (O, PV, PD, MD, AD, and PL) as well as in the amygdala, with stronger responses for negative faces, also associated with an increase of the respiration rates of the monkey. Processing of dynamic facial expressions involves an extended network recruiting additional regions not known to be part of the face-processing network, suggesting that face motions may facilitate the recognition of facial expressions. We report for the first time in New World marmosets that the perception and identification of changeable facial expressions, vital for social communication, recruit face-selective brain patches also involved in face detection processing and are associated with an increase of arousal.SIGNIFICANCE STATEMENT Recent research in humans and nonhuman primates has highlighted the importance to correctly recognize and process facial expressions to understand others' emotions in social interactions. The current study focuses on the fMRI responses of emotional facial expressions in the common marmoset (Callithrix jacchus), a New World primate species sharing several similarities of social behavior with humans. Our results reveal that temporal and frontal face patches are involved in both basic face detection and facial expression processing. The specific recruitment of these patches for negative faces associated with an increase of the arousal level show that marmosets process facial expressions of their congener, vital for social communication.

Neural correlates of psychodynamic and non-psychodynamic therapies in different clinical populations through fMRI: A meta-analysis and systematic review

Background

The COVID-19 pandemic has exacerbated the ongoing crisis in psychiatric and psychological care, contributing to what we have identified as a new psychological and psychiatric pandemic. Psychotherapy is an effective method for easing the psychological suffering experienced also by the various impacts of COVID-19. This treatment can be examined from a neurological perspective, through the application of brain imaging techniques. Specifically, the meta-analysis of imaging studies can aid in expanding researchers' understanding of the many beneficial applications of psychotherapy.

Objectives

We examined the functional brain changes accompanying different mental disorders with functional Magnetic Resonance Imaging (fMRI), through a meta-analysis, and systematic review in order to better understand the general neural mechanism involved in psychotherapy and the potential neural difference between psychodynamic and non-psychodynamic approaches.

Data sources

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were employed for our systematic review and meta-analysis. We conducted a computer-based literature search, following the Population, Intervention, Comparison and Outcomes (PICO) approach, to retrieve all published articles in English regarding the above-described topics from PubMed (MEDLINE), Scopus, and Web of Science.

Study eligibility criteria participants and interventions

We combined terms related to psychotherapy and fMRI: ("psychotherapy" [All Fields] OR "psychotherapy" [MeSH Terms] OR "psychotherapy" [All Fields] OR "psychotherapies" [All Fields] OR "psychotherapy s" [All Fields]) AND ("magnetic resonance imaging" [MeSH Terms]) OR ("magnetic"[All Fields] AND "resonance"[All Fields] AND "imaging"[All Fields]) OR ("magnetic resonance imaging"[All Fields] OR "fmri"[All Fields]). We considered (1) whole brain fMRI studies; (2) studies in which participants have been involved in a clinical trial with psychotherapy sessions, with pre/post fMRI; (3) fMRI results presented in coordinate-based (x, y, and z) in MNI or Talairach space; (4) presence of neuropsychiatric patients. The exclusion criteria were: (1) systematic review or meta-analysis; (2) behavioral study; (3) single-case MRI or fMRI study; and (4) other imaging techniques (i.e., PET, SPECT) or EEG.

Results

After duplicates removal and assessment of the content of each published study, we included 38 sources. The map including all studies that assessed longitudinal differences in brain activity showed two homogeneous clusters in the left inferior frontal gyrus, and caudally involving the anterior insular cortex (p < 0.0001, corr.). Similarly, studies that assessed psychotherapy-related longitudinal changes using emotional or cognitive tasks (TASK map) showed a left-sided homogeneity in the anterior insula (p < 0.000) extending to Broca's area of the inferior frontal gyrus (p < 0.0001) and the superior frontal gyrus (p < 0.0001). Studies that applied psychodynamic psychotherapy showed Family-Wise Error (FWE) cluster-corrected (p < 0.05) homogeneity values in the right superior and inferior frontal gyri, with a small cluster in the putamen. No FWE-corrected homogeneity foci were observed for Mindful- based and cognitive behavioral therapy psychotherapy. In both pre- and post-therapy results, studies showed two bilateral clusters in the dorsal anterior insulae (p = 0.00001 and p = 0.00003, respectively) and involvement of the medial superior frontal gyrus (p = 0.0002).

Limitations

Subjective experiences, such as an individual's response to therapy, are intrinsically challenging to quantify as objective, factual realities. Brain changes observed both pre- and post-therapy could be related to other factors, not necessary to the specific treatment received. Therapeutic modalities and study designs are generally heterogeneous. Differences exist in sample characteristics, such as the specificity of the disorder and number and duration of sessions. Moreover, the sample size is relatively small, particularly due to the paucity of studies in this field and the little contribution of PDT.

Conclusions and implications of key findings

All psychological interventions seem to influence the brain from a functional point of view, showing their efficacy from a neurological perspective. Frontal, prefrontal regions, insular cortex, superior and inferior frontal gyrus, and putamen seem involved in these neural changes, with the psychodynamic more linked to the latter three regions.

Individual- and Connectivity-Based Real-Time fMRI Neurofeedback to Modulate Emotion-Related Brain Responses in Patients with Depression: A Pilot Study

INTRODUCTION

Individual real-time functional magnetic resonance imaging neurofeedback (rtfMRI NF) might be a promising adjuvant in treating depressive symptoms. Further studies showed functional variations and connectivity-related changes in the dorsolateral prefrontal cortex (dlPFC) and the insular cortex.

OBJECTIVES

The aim of this pilot study was to investigate whether individualized connectivity-based rtfMRI NF training can improve symptoms in depressed patients as an adjunct to a psychotherapeutic programme. The novel strategy chosen for this was to increase connectivity between individualized regions of interest, namely the insula and the dlPFC.

METHODS

Sixteen patients diagnosed with major depressive disorder (MDD, ICD-10) and 19 matched healthy controls (HC) participated in a rtfMRI NF training consisting of two sessions with three runs each, within an interval of one week. RtfMRI NF was applied during a sequence of negative emotional pictures to modulate the connectivity between the dlPFC and the insula. The MDD REAL group was divided into a Responder and a Non-Responder group. Patients with an increased connectivity during the second NF session or during both the first and the second NF session were identified as "MDD REAL Responder" (N = 6). Patients that did not show any increase in connectivity and/or a decreased connectivity were identified as "MDD REAL Non-Responder" (N = 7).

RESULTS

Before the rtfMRI sessions, patients with MDD showed higher neural activation levels in ventromedial PFC and the insula than HC; by contrast, HC revealed increased hemodynamic activity in visual processing areas (primary visual cortex and visual association cortex) compared to patients with MDD. The comparison of hemodynamic responses during the first compared to during the last NF session demonstrated significantly increased BOLD-activation in the medial orbitofrontal cortex (mOFC) in patients and HC, and additionally in the lateral OFC in patients with MDD. These findings were particularly due to the MDD Responder group, as the MDD Non-Responder group showed no increase in this region during the last NF run. There was a decrease of neural activation in emotional processing brain regions in both groups in the last NF run compared to the first: HC showed differences in the insula, parahippocampal gyrus, basal ganglia, and cingulate gyrus. Patients with MDD demonstrated deceased responses in the parahippocampal gyrus. There was no significant reduction of BDI scores after NF training in patients.

CONCLUSIONS

Increased neural activation in the insula and vmPFC in MDD suggests an increased emotional reaction in patients with MDD. The activation of the mOFC could be associated with improved control-strategies and association-learning processes. The increased lOFC activation could indicate a stronger sensitivity to failed NF attempts in MDD. A stronger involvement of visual processing areas in HC may indicate better adaptation to negative emotional stimuli after repeated presentation. Overall, the rtfMRI NF had an impact on neurobiological mechanisms, but not on psychometric measures in patients with MDD.

Abnormal resting-state functional connectivity of the insula in medication-free patients with obsessive-compulsive disorder

BACKGROUND

The function of the insula has been increasingly mentioned in neurocircuitry models of obsessive-compulsive disorder (OCD) for its role in affective processing and regulating anxiety and its wide interactions with the classic cortico-striato-thalamo-cortical circuit. However, the insular resting-state functional connectivity patterns in OCD remain unclear. Therefore, we aimed to investigate characteristic intrinsic connectivity alterations of the insula in OCD and their associations with clinical features.

METHODS

We obtained resting-state functional magnetic resonance imaging data from 85 drug-free OCD patients and 85 age- and sex-matched healthy controls (HCs). We performed a general linear model to compare the whole-brain intrinsic functional connectivity maps of the bilateral insula between the OCD and HC groups. In addition, we further explored the relationship between the intrinsic functional connectivity alterations of the insula and clinical features using Pearson or Spearman correlation analysis.

RESULTS

Compared with HCs, patients with OCD exhibited increased intrinsic connectivity between the bilateral insula and bilateral precuneus gyrus extending to the inferior parietal lobule and supplementary motor area. Decreased intrinsic connectivity was only found between the right insula and bilateral lingual gyrus in OCD patients relative to HC subjects, which was negatively correlated with the severity of depression symptoms in the OCD group.

CONCLUSION

In the current study, we identified impaired insular intrinsic connectivity in OCD patients and the dysconnectivity of the right insula and bilateral lingual gyrus associated with the depressive severity of OCD patients. These findings provide neuroimaging evidence for the involvement of the insula in OCD and suggest its potential role in the depressive symptoms of OCD.

An fMRI study of cognitive planning before and after symptom provocation in pediatric obsessive-compulsive disorder

BACKGROUND

Pediatric obsessive-compulsive disorder (OCD) has been associated with poorer planning in laboratory, school and home settings. It is unclear whether this impairment is a standalone cognitive issue or the result of OCD symptoms. No study has examined the influence of provoked distress on planning performance and neural correlates in pediatric OCD.

METHODS

Before and after a symptom provocation task, youth with OCD (n = 23; 9 boys; mean age ± standard deviation 15.1 ± 2.6 years) and matched healthy controls (n = 23) completed the Tower of London task during functional MRI scanning.

RESULTS

During planning, participants with OCD recruited the left superior frontal gyrus to a greater extent than healthy controls after symptom provocation (group × time point interaction; t ₄₄ = 5.22, p < 0.001). In a seeded, region of interest-constrained, functional connectivity analysis, we identified greater connectivity between the left superior frontal gyrus and the right middle frontal gyrus, left precuneus and left inferior parietal lobule in participants with OCD than healthy controls. We also identified greater connectivity between the right amygdala and right medial frontal gyrus in patients with OCD than healthy controls, but only before symptom provocation.

LIMITATIONS

The fixed-order design of the study and the number of participants taking medication (n = 20) should be noted.

CONCLUSION

Participants with OCD demonstrated greater amygdalar-cortical connectivity before symptom provocation, while sustaining greater recruitment and connectivity of task-related planning areas throughout the task. These results suggest that brain activity and connectivity is altered after symptom provocation, in the absence of impaired planning performance.

An Exploratory Study of a Novel Combined Therapeutic Modality for Obsessive-Compulsive Disorder

Objective: To explore whether a systematic combined therapeutic modality (CTM) could quickly and effectively improve the severity of obsessive–compulsive disorder (OCD) and the insight of OCD patients. Methods: Included in this study were 100 patients with OCD according to the 5th Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), for a 2-week short-term treatment. They were assigned to a drug-alone group (n = 57), and a CTM group (n = 43) using drug treatment in combination with cognitive behavioral treatment (CBT) and repetitive transcranial magnetic stimulation (rTMS). The therapeutic outcome was assessed by the Yale–Brown Obsessive–Compulsive Scale (Y-BOCS), Brown Assessment of Beliefs Scale (BABS), 24-item Hamilton Depression Scale (HAMD-24) and Hamilton Anxiety Scale (HAMA) before and after treatment. All data were treated with SPSS25.0 Software. Results: After the 2-week treatment, the success rate in the CTM group was significantly higher than that in the drug-alone group. Y-BOCS overall and factor scores were decreased as compared with those before treatment in both groups. HAMD, HAMA and BABS overall scores were all decreased after treatment in the CTM group. In addition, compared with the drug-alone group, the Y-BOCS overall score and factor score, HAMD overall score and HAMA overall score were all decreased significantly in CTM group, while the Y-BOCS score reduction rate was increased significantly. Insight was improved in eight cases (57.14%) in the CTM group containing 14 cases with poor insight. Multinomial logistic regression analysis showed that CTM was beneficial for the insight improvement of OCD patients (OR = 91.04–139.68); this improvement was more pronounced in patients with low baseline BABS overall scores (OR = 0.07). Conclusion: CTM may be an effective short-term strategy to improve the severity of OCD and insight of OCD patients and, therefore, is worthy of clinical promotion and application.

Metacognition and the effect of incentive motivation in two compulsive disorders: Gambling disorder and obsessive-compulsive disorder

AIMS

Compulsivity is a common phenotype among psychiatric disorders, such as obsessive-compulsive disorder (OCD) and gambling disorder (GD). Deficiencies in metacognition, such as the inability to estimate one's performance via confidence judgments could contribute to pathological decision-making. Earlier research has shown that patients with OCD exhibit underconfidence, while patients with GD exhibit overconfidence. Moreover, it is known that motivational states (e.g. monetary incentives) influence metacognition, with gain (respectively loss) prospects increasing (respectively decreasing) confidence. Here, we reasoned that OCD and GD symptoms might correspond to an exacerbation of this interaction between metacognition and motivation.

METHODS

We hypothesized GD's overconfidence to be exaggerated during gain prospects, while OCD's underconfidence to be worsened in loss context, which we expected to see represented in ventromedial prefrontal cortex (VMPFC) blood-oxygen-level-dependent activity. We tested those hypotheses in a task-based functional magnetic resonance imaging (fMRI) design (27 patients with GD, 28 patients with OCD, 55 controls). The trial is registered in the Dutch Trial Register (NL6171).

RESULTS

We showed increased confidence for patients with GD versus patients with OCD, which could partly be explained by sex and IQ. Although our primary analyses did not support the hypothesized interaction between incentives and groups, exploratory analyses did show increased confidence in patients with GD specifically in gain context. fMRI analyses confirmed a central role for VMPFC in the processing of confidence and incentives, but no differences between the groups.

CONCLUSION

Patients with OCD and those with GD reside at opposite ends of the confidence spectrum, while no interaction with incentives was found, nor group differences in neuronal processing of confidence.

Neuromodulation of OCD: A review of invasive and non-invasive methods

Early research into neural correlates of obsessive compulsive disorder (OCD) has focused on individual components, several network-based models have emerged from more recent data on dysfunction within brain networks, including the the lateral orbitofrontal cortex (lOFC)-ventromedial caudate, limbic, salience, and default mode networks. Moreover, the interplay between multiple brain networks has been increasingly recognized. As the understanding of the neural circuitry underlying the pathophysiology of OCD continues to evolve, so will too our ability to specifically target these networks using invasive and noninvasive methods. This review discusses the rationale for and theory behind neuromodulation in the treatment of OCD.

Aberrant cortico-striatal white matter connectivity and associated subregional microstructure of the striatum in obsessive-compulsive disorder

The striatum and its cortical circuits play central roles in the pathophysiology of obsessive-compulsive disorder (OCD). The striatum is subdivided by cortical connections and functions; however, the anatomical aberrations in different cortico-striatal connections and coexisting microstructural anomalies in striatal subregions of OCD patients are poorly understood. Thus, we aimed to elucidate the aberrations in cortico-striatal white matter (WM) connectivity and the associated subregional microstructure of the striatum in patients with OCD. From diffusion tensor/kurtosis imaging of 107 unmedicated OCD patients and 110 matched healthy controls (HCs), we calculated the cortico-striatal WM connectivity and segmented the striatum using probabilistic tractography. For the segmented striatal subregions, we measured average diffusion kurtosis values, which represent microstructural complexity. Connectivity and mean kurtosis values in each cortical target and associated striatal subregions were compared between groups. We identified significantly reduced orbitofrontal WM connectivity with its associated striatal subregion in patients with OCD compared to that in HCs. However, OCD patients exhibited significantly increased caudal-motor and parietal connectivity with the associated striatal subregions. The mean kurtosis values of the striatal subregions connected to the caudal-motor and parietal cortex were significantly decreased in OCD patients. Our results highlighted contrasting patterns of striatal WM connections with the orbitofrontal and caudal-motor/parietal cortices, thus supporting the cortico-striatal circuitry imbalance model of OCD. We suggest that aberrations in WM connections and the microstructure of their downstream regions in the caudal-motor-/parietal-striatal circuits may underlie OCD pathophysiology and further provide potential neuromodulation targets for the treatment of OCD.

Altered Regional Activity and Network Homogeneity within the Fronto-Limbic Network at Rest in Medicine-Free Obsessive–Compulsive Disorder

Functional abnormalities in brain areas within the fronto-limbic network have been widely reported in obsessive–compulsive disorder (OCD). However, region- and network-level brain activities of the fronto-limbic network at rest have not been simultaneously investigated in OCD. In this study, 40 medicine-free and non-comorbidity patients with OCD and 38 age-, education-, and gender-matched healthy controls (HCs) underwent a resting-state functional magnetic-resonance-imaging scan. Fractional amplitude of low-frequency fluctuations (fALFF), network homogeneity (NH), and support vector machine were used to analyze the data. Patients with OCD showed increased fALFF in the right orbital frontal cortex (OFC), increased NH in the left OFC, and decreased NH in the right putamen. Decreased NH of the right putamen was negatively correlated with the Y-BOCS total and compulsive behavior scores. Furthermore, a combination of NH in the left OFC and right putamen could be applied to differentiate OCD from HCs with optimum specificity and sensitivity. The current findings emphasize the crucial role of the fronto-limbic network in the etiology of OCD.

Changes in Volume of Subregions Within Basal Ganglia in Obsessive–Compulsive Disorder: A Study With Atlas-Based and VBM Methods

Background

The role of basal ganglia in the pathogenesis of obsessive–compulsive disorder (OCD) remains unclear. The studies on volume changes of basal ganglia in OCD commonly use the VBM method; however, the Atlas-based method used in such research has not been reported. Atlas-based method has a lower false positive rate compared with VBM method, thus having advantages partly.

Objectives

The current study aimed to detect the volume changes of subregions within basal ganglia in OCD using Atlas-based method to further delineate the precise neural circuitry of OCD. What is more, we explored the influence of software used in Atlas-based method on the volumetric analysis of basal ganglia and compared the results of Atlas-based method and regularly used VBM method.

Methods

We analyzed the brain structure images of 37 patients with OCD and 41 healthy controls (HCs) using the VBM method, Atlas-based method based on SPM software, or Freesurfer software to find the areas with significant volumetric variation between the two groups, and calculated the effects size of these areas.

Results

VBM analysis revealed a significantly increased volume of bilateral lenticular nucleus in patients compared to HCs. In contrast, Atlas-based method based on Freesurfer revealed significantly increased volume of left globus pallidus in patients, and the largest effect size of volumetric variation was revealed by Freesurfer analysis.

Conclusions

This study showed that the volume of bilateral lenticular nucleus significantly increased in patients compared to HCs, especially left globus pallidus, which was in accordance with the previous findings. In addition, Freesurfer is better than SPM and a good choice for Atlas-based volumetric analysis of basal ganglia.

Subcortical shape in pediatric and adult obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) implicates alterations in cortico-striato-thalamo-cortical and fronto-limbic circuits. Building on prior structural findings, this is the largest study to date examining subcortical surface morphometry in OCD.

METHODS

Structural magnetic resonance imaging data were collected from 200 participants across development (5-55 years): 28 youth and 75 adults with OCD and 27 psychiatrically healthy youth and 70 adults. General linear models were used to assess group differences and group-by-age interactions on subcortical shape (FSL FIRST).

RESULTS

Compared to healthy participants, those with OCD exhibited surface expansions on the right nucleus accumbens and inward left amygdala deformations, which were associated with greater OCD symptom severity ([Children's] Yale-Brown Obsessive-Compulsive Scale). Group-by-age interactions indicated that accumbens group differences were driven by younger participants and that right pallidum shape was associated inversely with age in healthy participants, but not in participants with OCD. No differences in the shape of other subcortical regions or in volumes (FreeSurfer) were detected in supplementary analyses.

CONCLUSIONS

This study is the largest to date examining subcortical shape in OCD and the first to do so across the developmental spectrum. NAcc and amygdala shape deformation builds on extant neuroimaging findings and suggests subtle, subregional alterations beyond volumetric findings. Results shed light on morphometric alterations in OCD, informing current pathophysiological models.

An overview of the first 5 years of the ENIGMA obsessive-compulsive disorder working group: The power of worldwide collaboration

Neuroimaging has played an important part in advancing our understanding of the neurobiology of obsessive-compulsive disorder (OCD). At the same time, neuroimaging studies of OCD have had notable limitations, including reliance on relatively small samples. International collaborative efforts to increase statistical power by combining samples from across sites have been bolstered by the ENIGMA consortium; this provides specific technical expertise for conducting multi-site analyses, as well as access to a collaborative community of neuroimaging scientists. In this article, we outline the background to, development of, and initial findings from ENIGMA's OCD working group, which currently consists of 47 samples from 34 institutes in 15 countries on 5 continents, with a total sample of 2,323 OCD patients and 2,325 healthy controls. Initial work has focused on studies of cortical thickness and subcortical volumes, structural connectivity, and brain lateralization in children, adolescents and adults with OCD, also including the study on the commonalities and distinctions across different neurodevelopment disorders. Additional work is ongoing, employing machine learning techniques. Findings to date have contributed to the development of neurobiological models of OCD, have provided an important model of global scientific collaboration, and have had a number of clinical implications. Importantly, our work has shed new light on questions about whether structural and functional alterations found in OCD reflect neurodevelopmental changes, effects of the disease process, or medication impacts. We conclude with a summary of ongoing work by ENIGMA-OCD, and a consideration of future directions for neuroimaging research on OCD within and beyond ENIGMA.

Inverse Association Between Resting-State Putamen Activity and Iowa Gambling Task Performance in Patients With Obsessive-Compulsive Disorder and Control Subjects

BACKGROUND

Symptoms of obsessive-compulsive disorder (OCD) have been conceptualized as manifestations of decision-making deficits. Patients with OCD exhibit impairment during the decision-making process, as assessed by the Iowa Gambling Task (IGT). This impairment is independent of clinical severity and disease progression. However, the association between the decision-making deficit and resting-state brain activity of patients with OCD has not been examined.

METHODS

Fifty unmedicated patients with OCD and 55 matched control subjects completed IGT. Resting-state brain activity was examined using the fractional amplitude of low-frequency fluctuations (fALFFs). fALFF analysis focused on the slow-4 and 5 bands. Group comparisons were performed to determine the association between IGT performance and fALFFs.

RESULTS

There was a significant group difference in the association between the IGT total net score and slow-4 fALFFs in the left putamen (voxel height threshold of p < 0.001; cluster size threshold of p < 0.05; family wise error-corrected). Higher putamen slow-4 fALFFs were correlated with lower IGT scores for OCD patients (r = -0.485; p < 0.0005) and higher IGT scores for control subjects (r = 0.402; p < 0.005). There was no group difference in the association between the IGT total net score and slow-5 fALFFs.

CONCLUSIONS

These findings in unmedicated patients demonstrate the importance of resting-state putamen activity for decision-making deficit associated with OCD, as measured by IGT. The inverse correlation may be explained by the hypersensitive response of the putamen in patients with OCD.

Left Amygdala Functional Connectivity Decreased after Fear of Negative Events was Disregarded in Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a chronic and debilitating mental disorder that affects patients throughout their lives, leading to a diminished quality of life for patients and families, reduced productivity, and higher health care costs. It is of clinical and theoretical importance to investigate a more efficacious therapeutic approach for OCD and the neurophysiological mechanism underlying the efficacy of treatment, potentially associated with the etiology of OCD. Recently, a novel psychotherapy designated cognitive-coping therapy (CCT) has been reported to have a large effect size in OCD treatment. CCT hypothesizes that fear of negative events plays a crucial role in OCD. The study entitled “Decreased left amygdala functional connectivity by cognitive-coping therapy in obsessive-compulsive disorder” attempted to investigate the potential neurophysiological mechanism underlying the efficacy of CCT for OCD. The study provides crystal evidence showing that 4-week pharmacotherapy plus CCT decreases the left amygdala seed-based functional connectivity (LA-FC) with the right anterior cingulate gyrus and the left paracentral lobule/the left superior parietal/left inferior parietal, and 4-week CCT decreases the LA-FC with the left middle occipital gyrus/the left superior parietal. The alteration of the LA-FC with the right anterior cingulate gyrus positively correlates to the reduction of the Yale-Brown obsessive-compulsive scale (Y-BOCS) score. Therefore, it provides new insights into understanding the neurophysiology and neuropsychology behind the onset and treatment of OCD.

Increased functional connectivity between presupplementary motor area and inferior frontal gyrus associated with the ability of motor response inhibition in obsessive-compulsive disorder

Recent evidence suggests that presupplementary motor area (pre‐SMA) and inferior frontal gyrus (IFG) play an important role in response inhibition. However, no study has investigated the relationship between these brain networks at resting‐state and response inhibition in obsessive–compulsive disorder (OCD). We performed resting‐state functional magnetic resonance imaging scans and then measured the response inhibition of 41 medication‐free OCD patients and 49 healthy control (HC) participants by using the stop‐signal task outside the scanner. We explored the differences between OCD and HC groups in the functional connectivity of pre‐SMA and IFG associated with the ability of motor response inhibition. OCD patients showed a longer stop‐signal reaction time (SSRT). Compared to HC, OCD patients exhibit different associations between the ability of motor response inhibition and the functional connectivity between pre‐SMA and IFG, inferior parietal lobule, dorsal anterior cingulate cortex, insula, and anterior prefrontal cortex. Additional analysis to investigate the functional connectivity difference from the seed ROIs to the whole brain voxels revealed that, compared to HC, OCD exhibited greater functional connectivity between pre‐SMA and IFG. Also, this functional connectivity was positively correlated with the SSRT score. These results provide additional insight into the characteristics of the resting‐state functional connectivity of the regions belonging to the cortico‐striato‐thalamo‐cortical circuit and the cingulo‐opercular salience network, underlying the impaired motor response inhibition of OCD. In particular, we emphasize the importance of altered functional connectivity between pre‐SMA and IFG for the pathophysiology of motor response inhibition in OCD.

Resting-state functional connectivity of the amygdala subregions in unmedicated patients with obsessive-compulsive disorder before and after cognitive behavioural therapy

BACKGROUND

Cognitive behavioural therapy (CBT) is considered an effective first-line treatment for obsessive-compulsive disorder (OCD). However, the neural basis of CBT for OCD has not yet been elucidated. The role of the amygdala in OCD and its functional coupling with the cerebral cortex have received increasing attention, and may provide new understanding of the neural basis of CBT for OCD.

METHODS

We acquired baseline resting-state functional MRI (fMRI) scans from 45 unmedicated patients with OCD and 40 healthy controls; we then acquired another wave of resting-state fMRI scans from the patients with OCD after 12 weeks of CBT. We performed seed-based resting-state functional connectivity analyses of the amygdala subregions to examine changes in patients with OCD as a result of CBT.

RESULTS

Compared to healthy controls, patients with OCD showed significantly increased resting-state functional connectivity at baseline between the left basolateral amygdala and the right middle frontal gyrus, and between the superficial amygdala and the right cuneus. In patients with OCD who responded to CBT, we found decreased resting-state functional connectivity after CBT between the amygdala subregions and the visual association cortices and increased resting-state functional connectivity between the amygdala subregions and the right inferior parietal lobe. Furthermore, these changes in resting-state functional connectivity were positively associated with changes in scores on the compulsion or obsession subscales of the Yale-Brown Obsessive-Compulsive Scale.

LIMITATIONS

Because of the lack of a second scan for healthy controls after 12 weeks, our results may have been confounded by other variables.

CONCLUSION

Our findings yield insights into the pathophysiology of OCD; they also reveal the potential neural changes elicited by CBT, and thus have implications for guiding effective treatment strategies with CBT for OCD.

Classification of Obsessive-Compulsive Disorder Using Distance Correlation on Resting-State Functional MRI Images

Both the Pearson correlation and partial correlation methods have been widely used in the resting-state functional MRI (rs-fMRI) studies. However, they can only measure linear relationship, although partial correlation excludes some indirect effects. Recent distance correlation can discover both the linear and non-linear dependencies. Our goal was to use the multivariate pattern analysis to compare the ability of such three correlation methods to distinguish between the patients with obsessive-compulsive disorder (OCD) and healthy control subjects (HCSs), so as to find optimal correlation method. The main process includes four steps. First, the regions of interest are defined by automated anatomical labeling (AAL). Second, functional connectivity (FC) matrices are constructed by the three correlation methods. Third, the best discriminative features are selected by support vector machine recursive feature elimination (SVM-RFE) with a stratified N-fold cross-validation strategy. Finally, these discriminative features are used to train a classifier. We had a total of 128 subjects out of which 61 subjects had OCD and 67 subjects were normal. All the three correlation methods with SVM have achieved good results, among which distance correlation is the best [accuracy = 93.01%, specificity = 89.71%, sensitivity = 95.08%, and area under the receiver-operating characteristic curve (AUC) = 0.94], followed by Pearson correlation and partial correlation is the last. The most discriminative regions of the brain for distance correlation are right dorsolateral superior frontal gyrus, orbital part of left superior frontal gyrus, orbital part of right middle frontal gyrus, right anterior cingulate and paracingulate gyri, left the supplementary motor area, and right precuneus, which are the promising biomarkers of OCD.

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.

Effects of visual attention modulation on dynamic functional connectivity during own-face viewing in body dysmorphic disorder

Body dysmorphic disorder (BDD) is characterized by preoccupations with misperceptions of one's physical appearance. Previous neuroimaging studies in BDD have yet to examine dynamic functional connectivity (FC) patterns between brain areas, necessary to capture changes in activity in response to stimuli and task conditions. We used Leading Eigenvector Dynamics Analysis to examine whole-brain dynamic FC from fMRI data during an own-face viewing task in 29 unmedicated adults with BDD with facial concerns and 30 healthy controls. The task involved two parts: (1) unconstrained, naturalistic viewing and (2) holding visual attention in the center of the image, to reduce scanning and fixation on perceived facial flaws. An FC state consisting of bilateral medial orbitofrontal cortex regions occurred significantly less often during the visual attention condition and afterward during the unconstrained face viewing in BDD participants, compared to the first unconstrained face viewing, a pattern that differed from controls. Moreover, the probability of this state during the second unconstrained face viewing was associated with severity of obsessions and compulsions and degree of poor insight in BDD, suggesting its clinical significance. These findings have implications for understanding the pathophysiology of own-face viewing in BDD and how it is affected by modification of viewing patterns, which may have implications for novel perceptual retraining treatment designs.

The Effects of Tryptamine Psychedelics in the Brain: A meta-Analysis of Functional and Review of Molecular Imaging Studies

There is an increasing interest in the neural effects of psychoactive drugs, in particular tryptamine psychedelics, which has been incremented by the proposal that they have potential therapeutic benefits, based on their molecular mimicry of serotonin. It is widely believed that they act mainly through 5HT2A receptors but their effects on neural activation of distinct brain systems are not fully understood. We performed a quantitative meta-analysis of brain imaging studies to investigate the effects of substances within this class (e.g., LSD, Psilocybin, DMT, Ayahuasca) in the brain from a molecular and functional point of view. We investigated the question whether the changes in activation patterns and connectivity map into regions with larger 5HT1A/5HT2A receptor binding, as expected from indolaemine hallucinogens (in spite of the often reported emphasis only on 5HT2AR). We did indeed find that regions with changed connectivity and/or activation patterns match regions with high density of 5HT2A receptors, namely visual BA19, visual fusiform regions in BA37, dorsal anterior and posterior cingulate cortex, medial prefrontal cortex, and regions involved in theory of mind such as the surpramarginal gyrus, and temporal cortex (rich in 5HT1A receptors). However, we also found relevant patterns in other brain regions such as dorsolateral prefrontal cortex. Moreover, many of the above-mentioned regions also have a significant density of both 5HT1A/5HT2A receptors, and available PET studies on the effects of psychedelics on receptor occupancy are still quite scarce, precluding a metanalytic approach. Finally, we found a robust neuromodulatory effect in the right amygdala. In sum, the available evidence points towards strong neuromodulatory effects of tryptamine psychedelics in key brain regions involved in mental imagery, theory of mind and affective regulation, pointing to potential therapeutic applications of this class of substances.

Altered Functional Connectivity Strength at Rest in Medication-Free Obsessive-Compulsive Disorder

Background

Previous studies explored the whole-brain functional connectome using the degree approach in patients with obsessive-compulsive disorder (OCD). However, whether the altered degree values can be used to discriminate OCD from healthy controls (HCs) remains unclear.

Methods

A total of 40 medication-free patients with OCD and 38 HCs underwent a resting-state functional magnetic resonance imaging (rs-fMRI) scan. Data were analyzed with the degree approach and a support vector machine (SVM) classifier.

Results

Patients with OCD showed increased degree values in the left thalamus and left cerebellum Crus I and decreased degree values in the left dorsolateral prefrontal cortex, right precuneus, and left postcentral gyrus. SVM classification analysis indicated that the increased degree value in the left thalamus is a marker of OCD, with an acceptable accuracy of 88.46%, sensitivity of 87.50%, and specificity of 89.47%.

Conclusion

Altered degree values within and outside the cortical-striatal-thalamic-cortical (CSTC) circuit may cocontribute to the pathophysiology of OCD. Increased degree values of the left thalamus can be used as a future marker for OCD understanding-classification.

Toward a neurocircuit-based taxonomy to guide treatment of obsessive-compulsive disorder

An important challenge in mental health research is to translate findings from cognitive neuroscience and neuroimaging research into effective treatments that target the neurobiological alterations involved in psychiatric symptoms. To address this challenge, in this review we propose a heuristic neurocircuit-based taxonomy to guide the treatment of obsessive-compulsive disorder (OCD). We do this by integrating information from several sources. First, we provide case vignettes in which patients with OCD describe their symptoms and discuss different clinical profiles in the phenotypic expression of the condition. Second, we link variations in these clinical profiles to underlying neurocircuit dysfunctions, drawing on findings from neuropsychological and neuroimaging studies in OCD. Third, we consider behavioral, pharmacological, and neuromodulatory treatments that could target those specific neurocircuit dysfunctions. Finally, we suggest methods of testing this neurocircuit-based taxonomy as well as important limitations to this approach that should be considered in future research.

Review Article: Anabolic-Androgenic Steroids, Violence, and Crime: Two Cases and Literature Review

BACKGROUND AND OBJECTIVES

Anabolic-androgenic steroid (AAS) use has become a major worldwide substance use disorder, affecting tens of millions of individuals. Importantly, it is now increasingly recognized that some individuals develop uncharacteristically violent or criminal behaviors when using AAS. We sought to summarize available information on this topic.

METHODS

We reviewed the published literature on AAS-induced behavioral effects and augmented this information with extensive observations from our clinical and forensic experience.

RESULTS

It is now generally accepted that some AAS users develop uncharacteristically violent or criminal behaviors while taking these drugs. Although these behaviors may partially reflect premorbid psychopathology, sociocultural factors, or expectational effects, accumulating evidence suggests that they are also attributable to biological effects of AAS themselves. The mechanism of these effects remains speculative, but preliminary data suggest a possible role for brain regions involved in emotional reactivity, such as the amygdala and regions involved in cognitive control, including the frontal cortex. For unknown reasons, these effects appear idiosyncratic; most AAS users display few behavioral effects, but a minority develops severe effects.

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

Professionals encountering AAS users in clinical or forensic settings should be alert to the possibility of AAS-induced violence or criminality and should employ strategies to assess whether AAS is indeed a contributory factor in a given case. Further research is needed to elucidate the mechanism of AAS-induced violence and to explain why only a subset of AAS users appears vulnerable to these effects. (Am J Addict 2021;00:00-00).

Effects of short-term cognitive-coping therapy on resting-state brain function in obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) tends to be treatment refractory. Recently, cognitive-coping therapy (CCT) for OCD is reported to be an efficacious psychotherapy. However, the underlying neurophysiological mechanism remains unknown. Here, the effects of CCT on OCD and the resting-state brain function were investigated.

METHODS

Fifty-nine OCD patients underwent CCT, pharmacotherapy plus CCT (pCCT), or pharmacotherapy. Before and after a 4-week treatment, Yale-Brown obsessive-compulsive scale (Y-BOCS) was evaluated and resting-state functional magnetic resonance imaging (rs-fMRI) was scanned.

RESULTS

Compared with the baseline, significant reduction of Y-BOCS scores was found after four-week treatment (p < .001) in groups of CCT and pCCT, not in pharmacotherapy. Post-treatment Y-BOCS scores of CCT group and pCCT group were not different, but significantly lower than that of pharmacotherapy group (p < .001). Compared with pretreatment, two clusters of brain regions with significant change in amplitude of low-frequency fluctuation (ALFF) were obtained in those who treated with CCT and pCCT, but not in those who received pharmacotherapy. The ALFF in cluster 1 (insula, putamen, and postcentral gyrus in left cerebrum) was decreased, while the ALFF in cluster 2 (occipital medial gyrus, occipital inferior gyrus, and lingual gyrus in right hemisphere) was increased after treatment (corrected p < .05). The changes of ALFF were correlated with the reduction of Y-BOCS score and were greater in remission than in nonremission. The reduction of the fear of negative events was correlated to the changes of ALFF of clusters and the reduction of Y-BOCS score.

CONCLUSIONS

The effectiveness of CCT for OCD was related to the alteration of resting-state brain function-the brain plasticity.

TRIAL REGISTRATION

ChiCTR-IPC-15005969.

Limbic cortico-striato-thalamo-cortical functional connectivity in drug-naïve patients of obsessive-compulsive disorder

BACKGROUND

The pathophysiology of obsessive-compulsive disorder (OCD) remains unclear despite extensive neuroimaging work on the disorder. Exposure to medication and comorbid mental disorders can confound the results of OCD studies. The goal of this study was to explore differences in brain functional connectivity (FC) within the cortico-striato-thalamo-cortical (CSTC) loop of drug-naïve and drug-free OCD patients and healthy controls (HCs).

METHODS

A total of 29 drug-naïve OCD patients, 22 drug-free OCD patients, and 25 HCs matched on age, gender and education level underwent functional magnetic resonance imaging scanning at resting state. Seed-based connectivity analyses were conducted among the three groups. The Yale Brown Obsessive Compulsive Scale and clinical inventories were used to assess the clinical symptoms.

RESULTS

Compared with HCs, the drug-naïve OCD patients had reduced FC within the limbic CSTC loop. In the drug-naïve OCD participants, we also found hyperconnectivity between the supplementary motor area and ventral and dorsal putamen (p < 0.05, corrected for multiple comparisons).

CONCLUSIONS

Exposure to antidepressants such as selective serotonin reuptake inhibitors may affect the function of some brain regions. Future longitudinal studies could help to reveal the pharmacotherapeutic mechanisms in these loops.

Functional Brain Imaging and OCD

In the last 20 years, functional magnetic resonance imaging (fMRI) has been extensively used to investigate system-level abnormalities in the brain of patients with obsessive-compulsive disorder (OCD). In this chapter, we start by reviewing the studies assessing regional brain differences between patients with OCD and healthy controls in task-based fMRI. Specifically, we review studies on executive functioning and emotional processing, protocols in which these patients have been described to show alterations at the behavioral level, as well as research using symptom provocation protocols. Next, we review studies on brain connectivity alterations, focusing on resting-state studies evaluating disruptions in fronto-subcortical functional connectivity and in cortical networks. Likewise, we also review research on effective connectivity, which, different from functional connectivity, allows for ascertaining the directionality of inter-regional connectivity alterations. We conclude by reviewing the most significant findings on a topic of translational impact, such as the use of different fMRI measurements to predict response across a variety of treatment approaches. Overall, results suggest that there exists a pattern of regions, involving, but not limited to, different nodes of the cortico-striatal-thalamo-cortical circuits, showing robust evidence of functional alteration across studies, although the nature of the alterations critically depends on the specific tasks and their particular demands. Moreover, such findings have been, to date, poorly translated into clinical practice. It is suggested that this may be partially accounted for by the difficulty to integrate into a common framework results obtained under a wide variety of analysis approaches.

Treatment-Specific Associations Between Brain Activation and Symptom Reduction in OCD Following CBT: A Randomized fMRI Trial

OBJECTIVE

The authors sought to examine whether brain activity is associated with treatment response to cognitive-behavioral therapy (CBT) in adolescents and adults with obsessive-compulsive disorder (OCD), and whether any associations are treatment specific relative to an active control psychotherapy (stress management therapy; SMT).

METHODS

Eighty-seven patients with OCD (age range 12-45 years; 57 female, 39 medicated) were randomly assigned to receive 12 weeks of CBT or SMT. Prior to treatment, functional MRI scans were conducted in patients performing an incentive flanker task, which probes brain activation to both cognitive control and reward processing. Voxelwise linear mixed-effects models examined whether baseline brain activation was differentially associated with change in scores on the Yale-Brown Obsessive Compulsive Scale (standard or Children's version) over the course of CBT or SMT treatment.

RESULTS

Within the CBT group, a better treatment response was significantly associated with greater pretreatment activation within the right temporal lobe and rostral anterior cingulate cortex during cognitive control and within the ventromedial prefrontal, orbitofrontal, lateral prefrontal, and amygdala regions during reward processing. In contrast, reduced pretreatment activation within a largely overlapping set of regions was significantly associated with a better treatment response to SMT.

CONCLUSIONS

The study findings demonstrate that associations between brain activation and treatment response were treatment specific to CBT relative to a control psychotherapy and that these associations were stable from adolescence to mature adulthood. Such treatment-specific associations are important for the development of biomarkers to personalize treatment in OCD.

Animal Models for OCD Research

OCD has lagged behind other psychiatric illnesses in the identification of molecular treatment targets, due in part to a lack of significant findings in genome-wide association studies. However, while progress in this area is being made, OCD's symptoms of obsessions, compulsions, and anxiety can be deconstructed into distinct neural functions that can be dissected in animal models. Studies in rodents and non-human primates have highlighted the importance of cortico-basal ganglia-thalamic circuits in OCD pathophysiology, and emerging studies in human post-mortem brain tissue point to glutamatergic synapse abnormalities as a potential cellular substrate for observed dysfunctional behaviors. In addition, accumulated evidence points to a potential role for neuromodulators including serotonin and dopamine in both OCD pathology and treatment. Here, we review current efforts to use animal models for the identification of molecules, cell types, and circuits relevant to OCD pathophysiology. We start by describing features of OCD that can be modeled in animals, including circuit abnormalities and genetic findings. We then review different strategies that have been used to study OCD using animal model systems, including transgenic models, circuit manipulations, and dissection of OCD-relevant neural constructs. Finally, we discuss how these findings may ultimately help to develop new treatment strategies for OCD and other related disorders.

Deep brain stimulation modulates directional limbic connectivity in obsessive-compulsive disorder

Deep brain stimulation is effective for patients with treatment-refractory obsessive-compulsive disorder. Deep brain stimulation of the ventral anterior limb of the internal capsule rapidly improves mood and anxiety with optimal stimulation parameters. To understand these rapid effects, we studied functional interactions within the affective amygdala circuit. We compared resting state functional MRI data during chronic stimulation versus 1 week of stimulation discontinuation in patients, and obtained two resting state scans from matched healthy volunteers to account for test-retest effects. Imaging data were analysed using functional connectivity analysis and dynamic causal modelling. Improvement in mood and anxiety following deep brain stimulation was associated with reduced amygdala-insula functional connectivity. Directional connectivity analysis revealed that deep brain stimulation increased the impact of the ventromedial prefrontal cortex on the amygdala, and decreased the impact of the amygdala on the insula. These results highlight the importance of the amygdala circuit in the pathophysiology of obsessive-compulsive disorder, and suggest a neural systems model through which negative mood and anxiety are modulated by stimulation of the ventral anterior limb of the internal capsule for obsessive-compulsive disorder and possibly other psychiatric disorders.

Deep brain stimulation of the subthalamic nucleus in obsessive-compulsives disorders: long-term follow-up of an open, prospective, observational cohort

BACKGROUND

Obsessive-compulsive disorder (OCD) is a major cause of disability in western country and responsible for severe impairment of quality of life. About 10% of patients present with severe OCD symptoms and require innovative treatment such as deep brain stimulation (DBS). Among possible targets, the non-motor subthalamic nucleus (STN) is a key node of the basal ganglia circuitry, strongly connected to limbic cortical areas known to be involved in OCD.

METHOD

We analysed, in a prospective, observational, monocentric, open label cohort, the effect of chronic non-motor STN-DBS in 19 patients with treatment-resistant OCD consecutively operated in a single centre. Severity of OCD was evaluated using the Yale and Brown Obsessive-Compulsive Scale (YBOCS). YBOCS scores at 6, 12 and 24 months postoperatively were compared with baseline. Responders were defined by >35% improvement of YBOCS scores. Global Assessment Functioning (GAF) scale was used to evaluate the impact of improvement.

RESULTS

At a 24-month follow-up, the mean YBOCS score improved by 53.4% from 33.3±3.5 to 15.8±9.1 (95% CI 11.2-20.4; p<0.0001). Fourteen out of 19 patients were considered as responders, 5 out of 19 being improved over 75% and 10 out of 19 over 50%. GAF scale improved by 92% from 34.1±3.9 to 66.4±18.8 (95% CI 56.7-76.1; p=0.0003). The most frequent adverse events consisted of transient DBS-induced hypomania and anxiety.

CONCLUSION

Chronic DBS of the non-motor STN is an effective and relatively safe procedure to treat severe OCD resistant to conventional management.

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.

Emotional face processing across neurodevelopmental disorders: a dynamic faces study in children with autism spectrum disorder, attention deficit hyperactivity disorder and obsessive-compulsive disorder

Autism spectrum disorder (ASD) is classically associated with poor face processing skills, yet evidence suggests that those with obsessive-compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD) also have difficulties understanding emotions. We determined the neural underpinnings of dynamic emotional face processing across these three clinical paediatric groups, including developmental trajectories, compared with typically developing (TD) controls. We studied 279 children, 5-19 years of age but 57 were excluded due to excessive motion in fMRI, leaving 222: 87 ASD, 44 ADHD, 42 OCD and 49 TD. Groups were sex- and age-matched. Dynamic faces (happy, angry) and dynamic flowers were presented in 18 pseudo-randomized blocks while fMRI data were collected with a 3T MRI. Group-by-age interactions and group difference contrasts were analysed for the faces vs. flowers and between happy and angry faces. TD children demonstrated different activity patterns across the four contrasts; these patterns were more limited and distinct for the NDDs. Processing happy and angry faces compared to flowers yielded similar activation in occipital regions in the NDDs compared to TDs. Processing happy compared to angry faces showed an age by group interaction in the superior frontal gyrus, increasing with age for ASD and OCD, decreasing for TDs. Children with ASD, ADHD and OCD differentiated less between dynamic faces and dynamic flowers, with most of the effects seen in the occipital and temporal regions, suggesting that emotional difficulties shared in NDDs may be partly attributed to shared atypical visual information processing.

Neuroimaging the emotional modulation of urge inhibition in Tourette Syndrome

Tourette Syndrome (TS) is a neuropsychiatric condition characterized by tics that are typically preceded by uncomfortable urges that build until the tic is performed. Both tics and their associated urges are commonly exacerbated during states of heightened emotion. However, the neural substrates that are responsible for the development of urges have not been fully elucidated, particularly with regards to the influence of emotion. In this study, we investigate the brain areas associated with the development of urges and their modulation by emotion in patients with TS. Moreover, we explore the influence of obsessive-compulsive symptoms (OCS) which are commonly comorbid in TS. Forty patients with TS and 20 healthy controls completed an emotional blink suppression paradigm while undergoing functional magnetic resonance imaging. For the paradigm, participants completed alternating blocks of blink inhibition and free blinking while viewing pictures of angry and neutral facial expressions. Compared to controls, patients exhibited greater activity in the superior temporal gyrus and midcingulate during the inhibition of urges. Within the patient group, tic severity was associated with activity in the superior frontal gyrus during the angry inhibition contrast as compared to neutral; greater premonitory urge severity was associated with greater activity in the hippocampus, middle temporal gyrus and in the subcortex; blink inhibition ability was negatively associated with activity in the thalamus and insula. There were no significant associations with OCS severity for the emotion-related contrasts. The observed activated regions may represent a network that produces urges in patients, or alternatively, could represent compensatory cortical activity needed to keep urges and tics under control during emotional situations. Additionally, our findings suggest that OCS in the context of TS is similar to traditional obsessive-compulsive disorder and is neurobiologically dissociable from tics.

A Systematic Review of Behavioral, Physiological, and Neurobiological Cognitive Regulation Alterations in Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is characterized by cognitive regulation deficits. However, the current literature has focused on executive functioning and emotional response impairments in this disorder. Herein, we conducted a systematic review of studies assessing the behavioral, physiological, and neurobiological alterations in cognitive regulation in obsessive-compulsive patients using the PubMed database. Most of the studies included explored behavioral (distress, arousal, and frequency of intrusive thoughts) and neurobiological measures (brain activity and functional connectivity) using affective cognitive regulation paradigms. Our results pointed to the advantageous use of reappraisal and acceptance strategies in contrast to suppression to reduce distress and frequency of intrusive thoughts. Moreover, we observed alterations in frontoparietal network activity during cognitive regulation. Our conclusions are limited by the inclusion of underpowered studies with treated patients. Nonetheless, our findings support the OCD impairments in cognitive regulation of emotion and might help to improve current guidelines for cognitive therapy.

Stable inhibition-related inferior frontal hypoactivation and fronto-limbic hyperconnectivity in obsessive-compulsive disorder after concentrated exposure therapy

•

Less IFG activation and more fronto-limbic connectivity was found in OCD.

•

IFG hypoactivation and fronto-limbic hyperconnectivity persisted after exposure therapy.

•

Activation and connectivity before treatment did not predict treatment outcome.

Response inhibition has previously been suggested as an endophenotype for obsessive–compulsive disorder (OCD), evidenced by studies showing worse task performance, and altered task-related activation and connectivity. However, it’s unclear if these measures change following treatment. In this study, 31 OCD patients and 28 healthy controls performed a stop signal task during 3 T functional magnetic resonance imaging before treatment, while 24 OCD patients and 17 healthy controls were rescanned one week and three months after concentrated exposure and response prevention over four consecutive days using Bergen 4-Day Format. To study changes over time we performed a longitudinal analysis on stop signal reaction time and task-related activation and amygdala connectivity during successful and failed inhibition. Results showed that there was no group difference in task performance. Before treatment, OCD patients compared to controls showed less inhibition-related activation in the right inferior frontal gyrus, and increased functional connectivity between the right amygdala and the right inferior frontal gyrus and pre-supplementary motor area. During error-processing, OCD patients versus controls showed less activation in the pre-SMA before treatment. These group differences did not change after treatment. Pre-treatment task performance, brain activation, and connectivity were unrelated to the degree of symptom improvement after treatment. In conclusion, inferior frontal gyrus hypoactivation and increased fronto-limbic connectivity are likely trait markers of OCD that remain after effective exposure therapy.

Morphopathological changes in obsessive-compulsive disorder

The pathophysiology of the obsessive-compulsive disorder (OCD) has been studied for many years using several structural magnetic resonance imaging, discovering that the anomalies of function and structure of the brain are widespread, they involve different areas, structures and circuits with a complex interconnectivity. More than that, these anomalies cover all the life of a patient, from early childhood, due to variations of developmental stages until adult life. The research is highly important also because OCD has a major hereditary factor, with the phenotype variance between 27–47% due to hereditary factors. Under this paper, that follows last 10 years studies in this area, we will find some relevant findings consisting on neuroanatomic changes, the morphology findings of striatum, globus pallidus and thalamus, the blood flow circuit changes in various regions of the brain, brain connectivity and various correlations of them. Not to forget that OCD must be understand as an emotional disorder but in the same time as a cognitive disorder too. This approach highlights the abnormalities that have been found in brain regions involved in the cognitive and emotional behavior, as for example: extended temporal, parietal, and occipital regions, anterior cingulate, frontal gyrus, amygdala.

White matter disruption in obsessive-compulsive disorder revealed by meta-analysis of tract-based spatial statistics

BACKGROUND

Exploring white matter (WM) microstructural alterations is a momentous step for gaining insights about underlying mechanisms of obsessive-compulsive disorder (OCD) and improving the efficacy of therapies for this condition. Many tract-based spatial statistics (TBSS) studies have revealed abnormalities of fractional anisotropy (FA; an index of WM integrity) in OCD. However, research works have not drawn robust conclusions. Therefore, we integrated the findings of TBSS studies to identify the most consistent FA changes in OCD using meta-analytical approach.

METHODS

Online databases were systematically searched for all TBSS studies comparing FA between patients with OCD and controls. A coordinate-based meta-analysis was performed using anisotropic effect size version of the seed-based d mapping software. Meanwhile, meta-regression was used to explore the potential association of clinical characteristics with regional FA abnormalities.

RESULTS

Our meta-analysis included 488 OCD patients and 519 controls across 17 datasets. FA reductions were identified in the genu of the corpus callosum and the left orbitofrontal WM in OCD patients relative to controls. Metaregression analyses showed that the FA in the left orbitofrontal WM was negatively and independently correlated with symptom severity and illness duration in patients with OCD.

CONCLUSIONS

The current study provides a quantitative overview of TBSS findings in OCD and demonstrates the most prominent and replicable WM abnormalities in OCD are in the anterior part of the brain including interhemispheric connection and orbitofrontal region. Additionally, our findings suggest that FA reduction in the orbitofrontal WM might be a potential biomarker in predicting disease severity and progression in patients with OCD.

Altered response to risky decisions and reward in patients with obsessive–compulsive disorder

BACKGROUND

Patients with obsessive–compulsive disorder (OCD) employ ritualistic behaviours to reduce or even neutralize the anxiety provoked by their obsessions. The presence of excessive rumination and indecision has motivated the view of OCD as a disorder of decision-making. Most studies have focused on the “cold,” cognitive aspects of decision-making. This study expands current understanding of OCD by characterizing the abnormalities associated with affective, or “hot” decision-making.

METHODS

We performed a functional MRI study in a sample of 34 patients with OCD and 33 sex- and age-matched healthy controls, during which participants made 2-choice gambles taking varying levels of risk.

RESULTS

During risky decisions, patients showed significantly reduced task-related activation in the posterior cingulum, lingual gyrus and anterior cingulate cortex. We identified significant group × risk interactions in the calcarine cortex, precuneus, amygdala and anterior cingulate cortex. During the outcome phase, patients with OCD showed stronger activation of the orbitofrontal cortex, anterior cingulate cortex and putamen in response to unexpected losses.

LIMITATIONS

The group of patients not receiving medication was very small (n = 5), which precluded us from assessing the effect of medication on risk-taking behaviour in these patients.

CONCLUSION

Obsessive–compulsive disorder is associated with abnormal brain activity patterns during risky decision-making in a set of brain regions that have been consistently implicated in the processing of reward prediction errors. Alterations in affective “hot” processes implicated in decision-making may contribute to increased indecisiveness and intolerance to uncertainty in patients with OCD.