Obsessive-compulsive Disorder Individuals Research Articles

Distinct cognitive and functional connectivity features from healthy cohorts can identify clinical obsessive-compulsive disorder.

Improving diagnostic accuracy of obsessive-compulsive disorder (OCD) using models of brain imaging data is a key goal of the field, but this objective is challenging due to the limited size and phenotypic depth of clinical datasets. Leveraging the phenotypic diversity in large non-clinical datasets such as the UK Biobank (UKBB), offers a potential solution to this problem. Nevertheless, it remains unclear whether classification models trained on non-clinical populations will generalise to individuals with clinical OCD. This question is also relevant for the conceptualisation of OCD; specifically, whether the symptomology of OCD exists on a continuum from normal to pathological. Here, we examined a recently published "meta-matching" model trained on functional connectivity data from five large normative datasets (N=45,507) to predict cognitive, health and demographic variables. Specifically, we tested whether this model could classify OCD status in three independent clinical datasets (N=345). We found that the model could identify out-of-sample OCD individuals. Notably, the most predictive functional connectivity features mapped onto known cortico-striatal abnormalities in OCD and correlated with genetic brain expression maps previously implicated in the disorder. Further, the meta-matching model relied upon estimates of cognitive functions, such as cognitive flexibility and inhibition, to successfully predict OCD. These findings suggest that variability in non-clinical brain and behavioural features can discriminate clinical OCD status. These results support a dimensional and transdiagnostic conceptualisation of the brain and behavioural basis of OCD, with implications for research approaches and treatment targets.

Disability and Family Burden among Individuals with Schizophrenia and Obsessive–Compulsive Disorder

Background: In recent years, the evaluation of disability in people with severe mental health disorders has grown in importance. Caregivers of individuals with chronic psychiatric diseases face a multitude of psychological challenges. The burden of care is the aggregate term for these challenges. The assessment of burden has become particularly important with the emergence of deinstitutionalization and the treating individuals in the community. Objective: The objective was to study the level of disability and family burden among family caregivers of individuals with schizophrenia and obsessive–compulsive disorder (OCD). Materials and Methods: A total of 120 patients (60 with schizophrenia and 60 with OCD) diagnosed as per the International Classification of Diseases-10 were selected purposively from a mental health institute in North India. The Indian Disability Evaluation and Assessment Scale was used for measuring disability, and the Family Burden Scale was administered to know the level of family burden. Results: Twenty-six percent of individuals with schizophrenia had a profound level of disability, and about 45% of individuals had a severe level of disability from both the groups; more than half (53%) of the OCD individuals reported moderate-level disability. The family burden was found high (53%) to moderate (46%) in both the groups. Conclusion: Although individuals with schizophrenia had more severe disability and family burden, individuals with OCD were not too far behind. A holistic management plan should address these parameters in addition to symptomatic recovery. Thus, the management planning should consider yielding better outcomes in both conditions.

Habit Learning in OCD: Preliminary Data from a Spanish Sample

IntroductionInstrumental learning involves goal-directed and habitual systems. The Slips-of-Action Task (SOAT) is extensively used to measure habit tendencies and the likelihood of making erroneous responses for devalued outcomes. The SOAT provides a Devaluation Sensitivity Index (DSI), a measure of the balance between relative goal-directed and habitual learning. Individuals with Obsessive-Compulsive Disorder (OCD) often engage in repetitive actions, suggesting a potential deficit in goal-directed control and an increased reliance on habitual learning. Previous literature has shown that medicated OCD adults performed worse on the SOAT task than healthy controls.ObjectivesTo compare habit learning performance in an unmedicated sample:-Goal 1: Between OCD and Healthy Controls (HC)-Goal 2: Across four groups: adult OCD, adult HC, children OCD, and children HC MethodsParticipants: Eighty-three participants (44 OCD patients and 38 healthy controls) completed the study with usable task data. The 44 OCD patients comprised 17 adults (mean age: 26.76 years, SD: 8.61 years) and 27 children/adolescents (mean age: 12.84 years, SD: 2.59 years). The 38 healthy controls included 17 adults (mean age: 30 years, SD: 7.49 years) and 21 children/adolescents (mean age: 14.1 years, SD: 2.19 years). All participants were unmedicated. Measures: Participants completed an adapted version of the “Fabulous Fruit Game”, which included an instrumental training phase to learn Stimulus-Response-Outcomes (S-R-O) associations and a SOAT to assess the strength of learned S-R-O associations. DSI was calculated by subtracting the percentage of responses made toward devalued outcomes from the percentage of responses made toward still valuable outcomes. Behavioral Analyses: Student’s t-test comparing individuals with OCD to HC and a ONEWAY ANOVA to examine group differences across multiple categories.ResultsGoal 1: DSI comparison between individuals with OCD and HC revealed a significant difference, with HC demonstrating superior performance (t (60.9) = 2.60, p = .012, Cohen’s d = .546). Goal 2: The overall DSI comparison across adult OCD, adult HC, children OCD, and children HC showed a non-significant difference (F(3) = 3.407, p = 0.22). However, post hoc analysis revealed significant differences between Adult HC and Youth OCD (I-J Scheffe = 28.82, p = .033), indicating superior performance in adult HC.ConclusionsThis study highlights altered Habit Learning in unmedicated OCD individuals, supported by significant DSI differences compared to HC. Age-related distinctions were observed, emphasizing the need for age-sensitive interventions in understanding and addressing habit-related challenges in OCD.Disclosure of InterestNone Declared

Age of onset of obsessive-compulsive disorder differentially affects white matter microstructure

Previous diffusion MRI studies have reported mixed findings on white matter microstructure alterations in obsessive-compulsive disorder (OCD), likely due to variation in demographic and clinical characteristics, scanning methods, and underpowered samples. The OCD global study was created across five international sites to overcome these challenges by harmonizing data collection to identify consistent brain signatures of OCD that are reproducible and generalizable. Single-shell diffusion measures (e.g., fractional anisotropy), multi-shell Neurite Orientation Dispersion and Density Imaging (NODDI) and fixel-based measures, were extracted from skeletonized white matter tracts in 260 medication-free adults with OCD and 252 healthy controls. We additionally performed structural connectome analysis. We compared cases with controls and cases with early (<18) versus late (18+) OCD onset using mixed-model and Bayesian multilevel analysis. Compared with healthy controls, adult OCD individuals showed higher fiber density in the sagittal stratum (B[SE] = 0.10[0.05], P = 0.04) and credible evidence for higher fiber density in several other tracts. When comparing early (n = 145) and late-onset (n = 114) cases, converging evidence showed lower integrity of the posterior thalamic radiation —particularly radial diffusivity (B[SE] = 0.28[0.12], P = 0.03)—and lower global efficiency of the structural connectome (B[SE] = 15.3[6.6], P = 0.03) in late-onset cases. Post-hoc analyses indicated divergent direction of effects of the two OCD groups compared to healthy controls. Age of OCD onset differentially affects the integrity of thalamo-parietal/occipital tracts and the efficiency of the structural brain network. These results lend further support for the role of the thalamus and its afferent fibers and visual attentional processes in the pathophysiology of OCD.

The Prevalence and Comorbidity of Tic Disorders and Obsessive-Compulsive Disorder in Chinese School Students Aged 6-16: A National Survey.

Background: Obsessive-compulsive disorder (OCD) and tic disorders (TDs) are closely related and considered to etiologically overlap. Both disorders are characterized by repetitive behaviors. TD and OCD often co-occur. The high comorbidity between OCD and TD individuals suggests that we also need to pay more attention to the homogeneity and heterogeneity between TS and OCD. To date, there has been no systematic nationwide epidemiological survey of the mental health (including tic disorders and obsessive-compulsive disorder) of children and adolescents in China. Methods: A two-stage epidemiological study of psychiatric point prevalence was conducted. We used the multistage cluster stratified random sampling strategy to assess five provinces of China. The Child Behavior Checklist was used to identify behavioral problems among the enrolled students in the first stage. The results from the Mini-International Neuropsychiatric Interview for Children and Adolescents and evaluations from two psychiatrists based on the Diagnostic and Statistical Manual-IV were used to make a diagnosis. Point weighted prevalence for TD and OCD was estimated. We adjusted prevalence estimates with the product of sampling weights and poststratification weights. Standard error values and 95% confidential intervals were generated with Taylor series linearization. Rao–Scott adjusted chi-square (χ2) tests were employed to compare the prevalence estimates of different age and sex groups. Results: In the first stage, 73,992 participants aged 6–16 years old were selected. The prevalence rates of OCD and TDs were 1.37% (95% CI: 1.28–1.45) and 2.46% (95% CI: 2.35–2.57), respectively. The prevalence of OCD was found to be higher in girls (p < 0.001) and higher in boys with transient tic disorder (TTD) (p < 0.001) and Tourette’s syndrome (TS) (p < 0.001). The most common comorbidity of TS was OCD (40.73%), and for OCD, it was TS (11.36%). Conclusions: Our study is the first nationwide survey on the prevalence of TD (2.46%) and OCD (1.37%) in school students aged 6–16 years old in China. The high comorbidity between OCD and TD individuals suggested overlap based on the prevalence dimensions, which might be influenced by age and sex. This result suggested that we also need to pay more attention to the homogeneity and heterogeneity between TS and OCD.

Targeting Presupplementary Motor Area in OCD With tDCS and Continuous Theta Burst TMS

The pre-supplementary motor area (pSMA) is linked to structures implicated in obsessive-compulsive disorder (OCD), placing it in a position to influence behaviors central to the disorder. We assessed effects of pSMA tDCS and TMS on symptoms and brain function in OCD individuals.

Non-invasive brain stimulation modulates neural correlates of performance monitoring in patients with obsessive-compulsive disorder

Overactive performance monitoring, as reflected by enhanced neural responses to errors (the error-related negativity, ERN), is considered a biomarker for obsessive-compulsive disorder (OCD) and may be a promising target for novel treatment approaches. Prior research suggests that non-invasive brain stimulation with transcranial direct current stimulation (tDCS) may reduce the ERN in healthy individuals, yet no study has investigated its efficacy in attenuating the ERN in OCD. In this preregistered, randomized, sham-controlled, crossover study, we investigated effects of tDCS on performance monitoring in patients with OCD (n = 28) and healthy individuals (n = 28). Cathodal and sham tDCS was applied over the presupplementary motor area (pre-SMA) in two sessions, each followed by electroencephalogram recording during a flanker task. Cathodal tDCS reduced the ERN amplitude compared to sham tDCS, albeit this effect was only marginally significant (p = .052; mean difference: 0.86 μV). Additionally, cathodal tDCS reduced the correct-response negativity and increased the error positivity. These neural modulations were not accompanied by behavioral changes. Moreover, we found no evidence that the tDCS effect was more pronounced in the patient group. In summary, our findings indicate that tDCS over the pre-SMA modulates neural correlates of performance monitoring across groups. Therefore, this study represents a valuable starting point for future research to determine whether repeated tDCS application induces a more pronounced ERN attenuation and normalizes aberrant performance monitoring in the long term, thereby potentially alleviating obsessive-compulsive symptoms and providing a psychophysiological intervention strategy for individuals who do not benefit sufficiently from existing interventions.

Severity related neuroanatomical alteration across symptom dimensions in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a symptomatically heterogeneous disease. Symptoms of OCD can be grouped into a six-factor structure including washing, checking, neutralizing, obsessing, ordering and hoarding. These different symptom profiles might be one of the critical factors contributing to the inconsistent neuroanatomical findings in OCD according to the literature. In this study, whole-brain voxel-based morphometry was used to examine neuroanatomical alterations in gray matter (GM) for OCD compared to healthy controls, and the variations associated with differing symptoms of OCD. The high-quality structural imaging data from 39 OCD individuals and 42 age-matched healthy controls were recruited. First, we found increased cortical GM volume in the left postcentral gyrus in OCD participants compared to healthy controls. Next, six independent regression analyses were conducted to examine the correlation between OCD symptom dimensions and inter-individual variation in neuroanatomy. After a rigorous multiple comparison correction, greater hoarding symptom was robustly found associated with greater GM volumes at various frontotemporal regions (including orbitofrontal, middle frontal and superior temporal GMs). Additionally, greater washing symptoms were associated with increased GM volume at the superior temporal cortex. The symptom-specific GM alterations observed here support the notion that OCD is an etiologically heterogeneous disorder, with both overlapping and distinct neuroanatomical structure across symptom dimensions.

Stress Influences the Effect of Obsessive-Compulsive Symptoms on Emotion Regulation.

Obsessive-compulsive disorder (OCD) is associated with emotion regulation impairments, namely the frequent use of maladaptive strategies such as suppression and the decreased use of reappraisal strategies. Additionally, these patients exhibit elevated stress levels. Since stress exposure affects emotion regulation abilities, stress might influence the relationship between obsessive-compulsive symptoms and emotion regulation. In this study, we explored the effects of stress and obsessive-compulsive symptoms on emotion regulation in a sample of healthy and OCD individuals. We used self-reported psychometric scales to measure stress levels, obsessive-compulsive symptoms, and emotion reappraisal and suppression skills. We applied multiple regression and mediation analyses. Our results demonstrated that increased reappraisal scores were associated with higher suppression scores. Additionally, elevated stress values predicted increased scores for suppression and decreased scores for reappraisal. Furthermore, the reappraisal abilities resulted from a combination of a direct effect of obsessive-compulsive symptoms and an indirect effect of obsessive-compulsive symptoms mediated by stress. The reliance on suppression strategies and the difficulty in using reappraisal approaches are explained by stress levels and are not directly explained by obsessive-compulsive symptoms. This study highlights the necessity of targeting stress in current therapy-based treatments for OCD.

Compassion-Focused Group Therapy for Treatment-Resistant OCD: Initial Evaluation Using a Multiple Baseline Design.

Obsessive–compulsive disorder (OCD) is a debilitating mental health disorder that can easily become a treatment-resistant condition. Although effective therapies exist, only about half of the patients seem to benefit from them when we consider treatment refusal, dropout rates, and residual symptoms. Thus, providing effective augmentation to standard therapies could improve existing treatments. Group compassion-focused interventions have shown promise for reducing depression, anxiety, and avoidance related to various clinical problems, but this approach has never been evaluated for OCD individuals. However, cultivating compassion for self and others seems crucial for OCD patients, given the accumulating research suggesting that fear of guilt, along with isolation and self-criticism, can strongly contribute to the development and maintenance of OCD. The primary aim of this pilot study was to evaluate the acceptability, tolerability, and effectiveness of an 8-week group compassion-focused intervention for reducing OCD symptoms, depression, fear of guilt and self-criticism, and increasing common humanity and compassionate self-reassuring skills in treatment-resistant OCD patients. Using a multiple baseline experimental design, the intervention was evaluated in a sample of OCD patients (N = 8) who had completed at least 6 months of CBT treatment for OCD, but who continued to suffer from significant symptoms. Participants were randomized to different baseline assessment lengths; they then received 8 weekly, 120-min group sessions of compassion-focused therapy for OCD (CFT-OCD), and then were tested again at post-treatment and at 1 month follow up. Despite the adverse external circumstances (post-treatment and follow-up data collection were carried out, respectively, at the beginning and in the middle of the Italian lockdown due to the COVID-19 pandemic), by the end of treatment, all participants demonstrated reliable decreases in OCD symptoms, and these improvements were maintained at 4-week follow-up for seven of eight participants. The intervention was also associated with improvements in fear of guilt, self-criticism, and self-reassurance, but less consistent improvements in depression and common humanity. Participants reported high levels of acceptability of and satisfaction with the intervention. Results suggest that the intervention may be beneficial as either a stand-alone treatment or as an augmentation to other treatments.

Association of Orthorexic Tendencies with Obsessive-Compulsive Symptoms, Eating Attitudes and Exercise.

PurposeThe term orthorexia nervosa is used to describe the pathological fixation associated with consuming healthy food. It is assumed that orthorexia nervosa shares some phenomenological features with anorexia nervosa, obsessive-compulsive disorder (OCD), and other mental disorders. Individuals with orthorexic tendencies may have high physical activity as well as a healthy diet. This study aimed to investigate the relationship of orthorexia nervosa with obsessive-compulsive symptoms, eating attitudes, and several sociodemographic features.Patients and MethodsWe included 63 patients diagnosed with OCD, 63 healthy volunteers who perform physical exercises at least three days a week, at least 30 minutes a day, and 63 healthy volunteers who do not perform physical exercises regularly. Sociodemographic data form, Yale-Brown Obsessive Compulsive Scale, ORTO-11 Scale, Eating Attitude Test, Hamilton Anxiety Scale, and Structured Clinical Interview for DSM-5 Disorders (SCID-5 CV) were administered to all participants. OCD data form was also applied to patients with OCD diagnosis.ResultsWe found a statistically significant relationship between current order-symmetry obsessions and orthorexic tendencies in patients with OCD (p<0.05). There was no relationship between the severity of the disorder and orthorexia nervosa in patients with OCD (p>0.05). Orthorexic tendencies were found to increase as impaired eating attitudes increased in participants who regularly performed physical exercises and patients with OCD (p<0.05). The orthorexic tendencies of participants who regularly performed physical exercises were higher than those diagnosed with OCD and healthy individuals who did not perform physical exercises.ConclusionThe absence of a significant relationship between disorder severity and orthorexia nervosa in patients diagnosed with OCD and the increase in orthorexic tendencies as the deterioration in eating attitudes increases in both patients with OCD and the participants who regularly perform physical exercises suggest that orthorexia nervosa may be closer to the eating disorders group than obsessive-compulsive spectrum. Studies with large samples and different diagnoses are needed to determine the place of orthorexia nervosa in diagnosis and classification systems.

Examining subjective sleep quality in adults with hoarding disorder

Hoarding disorder (HD), characterized by difficulty parting with possessions and functionally impairing clutter, affects 2–6% of the population. Originally considered part of Obsessive-Compulsive Disorder (OCD), HD became a distinct diagnostic entity in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013. While sleep impacts OCD, little is known about sleep in HD. As HD patients often report poor sleep in clinical settings, understanding global subjective sleep quality and disturbances may lead to novel therapeutic targets. To address this gap, the authors used a sample of convenience: an existing data set designed to screen research study eligibility and explore the psychopathology and phenomenology of OCD and HD. The data set included information collected from individuals with HD (n = 38), OCD (n = 26), and healthy participants (n = 22) about insomnia, sleep quality, and mood using interviews and structured instruments including the Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), and Depression Anxiety Stress Scales (DASS). In this data set, HD and OCD groups reported significantly greater insomnia symptoms and poorer sleep quality compared with healthy controls while controlling for depression, age, and gender. A sizable minority of HD and OCD individuals met criteria for comorbid sleep disorders. OCD and HD groups differed in delayed sleep phase prevalence. To our knowledge, this is the first study examining subjective sleep quality and insomnia in HD as compared to healthy individuals and those with OCD, while controlling for relevant clinical characteristics. Given that there are evidence-based treatments for insomnia and other sleep disorders, our study raises the possibility that treatment interventions targeting sleep may improve HD outcomes.

Olfactory Dysfunction in Neurodevelopmental Disorders: A Meta-analytic Review of Autism Spectrum Disorders, Attention Deficit/Hyperactivity Disorder and Obsessive-Compulsive Disorder.

Olfactory dysfunction is recognized in neurodevelopmental disorders and may serve as an early indicator of global dysfunction. The present meta-analysis measures olfaction effect sizes in attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASDs), and obsessive-compulsive disorder (OCD). Meta-analysis included 320 ADHD, 346 ASD, and 208 OCD individuals as compared to 910 controls. Olfactory performance deficits were small-to-moderate and heterogeneous (d = - 0.42, 95% CI = - 0.59 < δ < - 0.25). Meta-analytic results indicate that olfactory dysfunction is evident in individuals with ASD and OCD, with small-to-negligible effects in ADHD. These findings imply olfactory dysfunction is related to clinical phenotype in ASD and OCD, but not ADHD, and warrant inclusion in clinical assessment and evaluation of certain neurodevelopmental disorders.

B-41 SPECT Differences between Obsessive Compulsive Disorder and Post-Traumatic Stress Disorder (PTSD)

Abstract Objective To assess whether diagnosed Obsessive Compulsive Disorder (OCD) and Post Traumatic Stress Disorder (PTSD) interactively alter brain activity, as measured by a Single Photon Emission Computed Tomography (SPECT) imaging. Method The sample included adults diagnosed with OCD (n = 915) with a mean age of 34.65 and predominantly male (68.6%) and adults with PTSD (n = 1,481) which had a mean age of 41.33 and was predominantly female (57.2%). Significant differences were observed for gender . Multiple ANCOVAs were conducted to determine differences between cerebral blood flow (CBF)in 17 different brain regions. Results Results showed hyper-perfusion in the PTSD group as compared to the OCD group in the pariental L/R[F(1,2393) = 6.47,p &lt; 0.01/F(1,2393) = 12.31,p &lt; .01], motor sensory L/R[F(1,2393) = 19.33,p &lt; .001/F(1,2393) = 17.32,p &lt; .01] and temporal left [F(1,2393) = 12.49,p &lt; .01]. Conclusion Significantly higher rCBF in the pariental and motor sensory for OCD individuals may be due to visual-constructive and controlled fluency which are usually associated with compulsion. Due to the hyperalert nature related with OCD rituals, these areas are more active when compared to PTSD. Hyperfusion was reported for PTSD in the left temporal lobe compared to OCD, this region is usually associated with registering potential threasts in the environment. This can be explained by the hypervigilant conduct seen in individuals with PTSD. Overall, it appears that individuals with OCD struggle with continual inability to inhibit repetitive thoughts and behaviors due to the over activation in the motor sensory and parietal region. Alternatively, the activation in PTSD individuals can be a result of a way to help them cope with threats in the environment.

The Neural Correlates of Probabilistic Classification Learning in Obsessive-Compulsive Disorder: A Pilot Study.

Individuals suffering from obsessive-compulsive disorder (OCD) have been found to show deficits in implicitly learning probabilistic associations between events. Neuroimaging studies have associated these implicit learning deficits in OCD individuals with aberrant activation of the striatal system. Recent behavioral studies have highlighted that probabilistic classification learning (PCL) deficits in OCD individuals only occur in a disorder-specific context, while PCL remains intact in a neutral context. The neural correlates of implicit learning in an OCD-specific context, however, have not yet been investigated. Using functional magnetic resonance imaging during a neutral (prediction of weather) and an OCD-specific variant (prediction of a virus epidemic) of a PCL paradigm, we assessed brain activity associated with implicit learning processes in 10 participants with OCD and 10 matched healthy controls. Regions of interest (ROIs) were the striatum and the medial temporal lobe. ROI analyses revealed a significantly higher activity in the bilateral putamen and the left hippocampus of OCD participants as compared to healthy controls during both PCL tasks. The group differences could partly be subsumed under a group × task interaction effect with OCD participants showing a significantly higher activity than healthy controls in the left putamen and the left hippocampus in the OCD-specific task variant only. These results suggest a compensation of aberrant striatal activity by an augmented engagement of the explicit memory system particularly in a disorder-relevant context in OCD participants.

Inflammatory dysregulation of monocytes in pediatric patients with obsessive-compulsive disorder

BackgroundAlthough the exact etiology of obsessive-compulsive disorder (OCD) is unknown, there is growing evidence of a role for immune dysregulation in the pathophysiology of the disease, especially in the innate immune system including the microglia. To test this hypothesis, we studied inflammatory markers in monocytes from pediatric patients with OCD and from healthy controls.MethodsWe determined the percentages of total monocytes, CD16+ monocytes, and classical (CD14highCD16−), intermediate (CD14highCD16low), and non-classical (CD14lowCD16high) monocyte subsets in 102 patients with early-onset OCD and in 47 healthy controls. Moreover, proinflammatory cytokine production (GM-CSF, IL-1β, IL-6, IL-8, and TNF-α) was measured by multiplex Luminex analysis in isolated monocyte cultures, in basal conditions, after exposure to lipopolysaccharide (LPS) to stimulate immune response or after exposure to LPS and the immunosuppressant dexamethasone.ResultsOCD patients had significantly higher percentages of total monocytes and CD16+ monocytes than healthy controls, mainly due to an increase in the intermediate subset but also in the non-classical monocytes. Monocytes from OCD patients released higher amounts of GM-CSF, IL-1β, IL-6, IL-8, and TNF-α than healthy controls after exposure to LPS. However, there were no significant differences in basal cytokine production or the sensitivity of monocytes to dexamethasone treatment between both groups. Based on monocyte subset distribution and cytokine production after LPS stimulation, patients receiving psychoactive medications seem to have an intermediate inflammatory profile, that is, lower than non-medicated OCD individuals and higher than healthy controls.ConclusionsThese results strongly support the involvement of an enhanced proinflammatory innate immune response in the etiopathogenesis of early-onset OCD.

Pregenual Anterior Cingulate Dysfunction Associated with Depression in OCD: An Integrated Multimodal fMRI/1H MRS Study.

Depression is a commonly occurring symptom in obsessive-compulsive disorder (OCD), and is associated with worse functional impairment, poorer quality of life, and poorer treatment response. Understanding the underlying neurochemical and connectivity-based brain mechanisms of this important symptom domain in OCD is necessary for development of novel, more globally effective treatments. To investigate biopsychological mechanisms of comorbid depression in OCD, we examined effective connectivity and neurochemical signatures in the pregenual anterior cingulate cortex (pACC), a structure known to be involved in both OCD and depression. Resting-state functional magnetic resonance imaging (fMRI) and 1H magnetic resonance spectroscopy (MRS) data were obtained from participants with OCD (n=49) and healthy individuals of equivalent age and sex (n=25). Granger causality-based effective (directed) connectivity was used to define causal networks involving the right and left pACC. The interplay between fMRI connectivity, 1H MRS and clinical data was explored by applying moderation and mediation analyses. We found that the causal influence of the right dorsal anterior midcingulate cortex (daMCC) on the right pACC was significantly lower in the OCD group and showed significant correlation with depressive symptom severity in the OCD group. Lower and moderate levels of glutamate (Glu) in the right pACC significantly moderated the interaction between right daMCC-pACC connectivity and depression severity. Our results suggest a biochemical-connectivity-psychological model of pACC dysfunction contributing to depression in OCD, particularly involving intracingulate connectivity and glutamate levels in the pACC. These findings have implications for potential molecular and network targets for treatment of this multi-faceted psychiatric condition.

Attentional avoidance of threats in obsessive compulsive disorder: An event related potential study

The neural mechanism underlying attentional bias in OCD (Obsessive-Compulsive Disorder) remains unclear. The goal of this study was to examine and compare the time course and the event related potential (ERP) components in OCD patients and healthy controls (HC) to reveal the complex brain activation pattern associated with attentional bias in OCD. The behavioural and electroencephalogram (EEG) data were recorded while the participants performed an emotional Stroop task. Compared to HC, the individuals with OCD exhibited slower response time, prolonged N1 latency and larger N1 and P2 amplitudes across different emotional words. In addition, we discovered that the OCD group showed an enlarged N1 component to OCD-related threat words compared to neutral words. Moreover, the OCD group had decreased P3 and later positive potential (LPP) amplitudes towards all types of words compared to the HC group. More importantly, the OCD group manifested smaller LPP amplitude to threat words compared to the HC group. Our findings suggest that OCD individuals may excessively direct their attention away from the threat at the late processing stage, probably due to the intensive processing or overestimation of the stimuli in the early automatic processing stage.

Inflammation in the Neurocircuitry of Obsessive-Compulsive Disorder

For a small percentage of obsessive-compulsive disorder (OCD) cases exhibiting additional neuropsychiatric symptoms, it was proposed that neuroinflammation occurs in the basal ganglia as an autoimmune response to infections. However, it is possible that elevated neuroinflammation, inducible by a diverse range of mechanisms, is important throughout the cortico-striato-thalamo-cortical circuit of OCD. Identifying brain inflammation is possible with the recent advance in positron emission tomography (PET) radioligands that bind to the translocator protein (TSPO). Translocator protein density increases when microglia are activated during neuroinflammation and the TSPO distribution volume (VT) is an index of TSPO density. To determine whether TSPO VT is elevated in the dorsal caudate, orbitofrontal cortex, thalamus, ventral striatum, dorsal putamen, and anterior cingulate cortex in OCD. This case-control study was conducted at a tertiary care psychiatric hospital from May 1, 2010, to November 30, 2016. Participants with OCD (n = 20) and age-matched healthy control individuals (n = 20) underwent a fluorine F 18-labeled N-(2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide PET scan. It is a high-quality second-generation TSPO-binding PET radiotracer. All participants were drug and medication free, nonsmoking, and otherwise healthy. The TSPO VT was measured in the dorsal caudate, orbitofrontal cortex, thalamus, ventral striatum, dorsal putamen, and anterior cingulate cortex. Compulsions were assessed with the Yale-Brown Obsessive Compulsive Scale. In the OCD and healthy groups, the mean (SD) ages were 27.4 (7.1) years and 27.6 (6.6) years, respectively, and 11 (55%) and 8 (40%) were women, respectively. In OCD, TSPO VT was significantly elevated in these brain regions (mean, 32%; range, 31%-36% except anterior cingulate cortex, 24%; analysis of variance, effect of diagnosis: P < .001 to P = .004). Slightly lower elevations in TSPO VT (22%-29%) were present in other gray matter regions. The Yale-Brown Obsessive Compulsive Scale measure of distress associated with preventing compulsive behaviors significantly correlated with TSPO VT in the orbitofrontal cortex (uncorrected Pearson correlation r = 0.62; P = .005). To our knowledge, this is the first study demonstrating inflammation within the neurocircuitry of OCD. The regional distribution of elevated TSPO VT argues that the autoimmune/neuroinflammatory theories of OCD should extend beyond the basal ganglia to include the cortico-striato-thalamo-cortical circuit. Immunomodulatory therapies should be investigated in adult OCD, rather than solely childhood OCD, particularly in cases with prominent distress when preventing compulsions.

Cognitive performance in a subclinical obsessive-compulsive sample: Emotional processing and quality of life

There is a stronger focus on understanding emotional processing in obsessive-compulsive disorder (OCD). This follows the assumption that the orbitofrontal cortex may be impaired. The ability to recognize and name odours probe emotional processing and thus orbitofrontal cortex functioning. The aim of this exploratory study was to investigate whether olfactory naming performance in individuals reporting subclinical obsessive-compulsive (OC) tendencies is impaired. This would allow a better understanding of differences and similarities in emotional processing between OCD patients and individuals reporting OC tendencies. The assessment of OC tendencies was measured with two standardized questionnaires (Yale-Brown Obsessive Compulsive Disorder Scale and Cognitive Assessment Instrument of Obsessions and Compulsions). The performance on a smell naming test in a subclinical group was compared to a group of individuals not reporting OC tendencies, and constituted the nonclinical control group. The subclinical group performed to the same standard as the nonclinical control group in naming both unpleasant and pleasant smells. It cannot be assumed that individuals showing OC tendencies are impaired in emotional processing as found in diagnosed OCD patients. Nevertheless, it is argued that the interaction between cognition and emotion, for example, intact attentional processing of emotional information is vital to reduce the intensity, frequency and duration of OC tendencies, thus underpinning experiences that promote better quality of social and working life.