Obsessive-compulsive Disorder Group Research Articles

The relationship between obsessive-compulsive symptoms and real-life functioning in schizophrenia: New insights from the multicenter study of the Italian Network for Research on Psychoses.

Although obsessive-compulsive disorder (OCD) is highly prevalent in schizophrenia, its relationship with patients' real-life functioning is still controversial. The present study aims at investigating the prevalence of OCD in a large cohort of non-preselected schizophrenia patients living in the community and verifying the relationship of OCD, as well as of other psychopathological symptoms, with real-life functioning along a continuum of OCD severity and after controlling for demographic variables. A sample of 327 outpatients with schizophrenia was enrolled in the study and collapsed into three subgroups according to OCD severity (subclinical, mild-moderate, severe). A series of structural equation modeling (SEM) was performed to analyze in each subgroup the association of obsessive-compulsive symptoms with real-life functioning, assessed through the Specific Levels of Functioning Scale and the UCSD Performance-Based Skills Assessment. Moreover, latent profile analysis (LPA) was performed to infer latent subpopulations. In the subclinical OCD group, obsessive-compulsive symptoms (OCS) were not associated with functioning, whereas in the mild-moderate OCD group, they showed a positive relationship, particularly in the domains of work and everyday life skills. The paucity of patients with severe OCD did not allow performing SEM analysis in this group. Finally, LPA confirmed a subgroup with mild-moderate OCS and more preserved levels of functioning. These findings hint at a positive association between mild-moderate OCD and real-life functioning in individuals with schizophrenia and encourage a careful assessment of OCD in personalized programs to sustain daily life activities.

Comparing the 'When' and the 'Where' of Electrocortical Activity in Patients with Tourette Syndrome, Body-Focused Repetitive Behaviors, and Obsessive Compulsive Disorder.

Background/Objectives: Tourette Syndrome (TS), Obsessive Compulsive Disorder (OCD), and Body-Focused Repetitive Behaviors (BFRB) are three disorders that share many similarities in terms of phenomenology, neuroanatomy, and functionality. However, despite the literature pointing toward a plausible spectrum of these disorders, only a few studies have compared them. Studying the neurocognitive processes using Event-Related Potentials (ERPs) offers the advantage of assessing brain activity with excellent temporal resolution. The ERP components can then reflect specific processes known to be potentially affected by these disorders. Our first goal is to characterize 'when' in the processing stream group differences are the most prominent. The second goal is to identify 'where' in the brain the group discrepancies could be. Methods: Participants with TS (n = 24), OCD (n = 18), and BFRB (n = 16) were matched to a control group (n = 59) and were recorded with 58 EEG electrodes during a visual counting oddball task. Three ERP components were extracted (i.e., P200, N200, and P300), and generating sources were modelized with Standardized Low-Resolution Electromagnetic Tomography. Results: We showed no group differences for the P200 and N200 when controlling for anxiety and depressive symptoms, suggesting that the early cognitive processes reflected by these components are relatively intact in these populations. Our results also showed a decrease in the later anterior P300 oddball effect for the TS and OCD groups, whereas an intact oddball effect was observed for the BFRB group. Source localization analyses with sLORETA revealed activations in the lingual and middle occipital gyrus for the OCD group, distinguishing it from the other two clinical groups and the controls. Conclusions: It seems that both TS and OCD groups share deficits in anterior P300 activation but reflect distinct brain-generating source activations.

Preliminary Examination of Sympathetic Magic as a Psychological Endophenotype for Obsessive-Compulsive Disorder

Although sympathetic magic (SM) beliefs (i.e., irrational understanding of contagion transmission) are observed in obsessive-compulsive disorder (OCD), it is unclear if such beliefs are psychological endophenotypes. Furthermore, predictors of SM beliefs in OCD remain unknown. Accordingly, the present study examined whether SM beliefs function as an endophenotype for OCD and whether perceived vulnerability to disease (PVD) contributes to SM beliefs. A sample of 30 individuals with OCD, 26 first-degree relatives, and 25 age-matched healthy controls completed self-report questionnaires and a SM task where we touched a clean pencil to a ‘contaminated’ toilet, and rated the degree to which the pencil was contaminated. A second pencil was touched to the first pencil and was then rated. This process was continued for 12 pencils (12 degrees of removal from contagion).Results revealed no significant differences in the extent to which the three groupsperceived a “chain of contagion” (i.e., contamination slopes) for the successive degrees of removal from the original contagion. However, the OCD group reported significantly less contamination reduction on the task, a group difference that was mediated by PVD. These findings suggest that although SM beliefs may not be an OCD endophenotype, such beliefs may derive from a PVD.

Structural and resting-state connection abnormalities of habenula in obsessive-compulsive disorder.

Previous studies have suggested that the habenula (Hb) may be involved in the mechanism of obsessive-compulsive disorder (OCD). However, the specific role of Hb in OCD remains unclear. This study aimed to explore the structural and functional abnormalities of Hb in OCD and their relationship with the clinical symptoms. Eighty patients with OCD and 85 healthy controls (HCs) were recruited as the primary dataset. The grey matter volume, resting-state functional connectivity (FC), and effective connectivity (EC) of the Hb were calculated and compared between OCD group and HCs. An independent replication dataset was used to verify the stability and robustness of the results. Patients with OCD exhibited smaller Hb volume and increased FC of right Hb-left hippocampus than HCs. Dynamic causal model revealed an increased EC from left hippocampus to right Hb and a less inhibitory causal influence from the right Hb to left hippocampus in the OCD group compared to HCs. Similar results were found in the replication dataset. This study suggested that abnormal structure of Hb and hippocampus-Hb connectivity may contribute to the pathological basis of OCD.

The Dynamics of Resting-State EEG and Salivary Trace Elements in Patients with Obsessive-Compulsive Disorder.

The study of salivary microelements and their neurophysiological and behavioral correlates in patients with obsessive-compulsive disorder (OCD) is a pressing issue in modern psychiatry, which, however, lacks adequate research at this time. In this study, we tested the dynamics of behavioral parameters, resting-state electroencephalogram (EEG), and salivary iron, copper, manganese, magnesium, and zinc in 30 healthy volunteers and 30 individuals with OCD before and after an emotional antisaccade task. The eye-movement data served as a measure of behavioral performance. Our research revealed consistently higher manganese concentrations in the OCD group compared to healthy volunteers associated with a higher EEG ratio of amplitude transformation and symptom severity. The dynamics of salivary microelements and resting-state EEG, possibly influenced by cognitive and emotional load during the anticsaccade task, differed between groups. In healthy volunteers, there was a decrease in salivary iron level with an increase in high-frequency power spectral density of EEG. The OCD group showed a decrease in salivary copper with an increased Hjorth mobility of EEG.

Temporal dynamics of autonomic nervous system responses under cognitive-emotional workload in obsessive-compulsive disorder.

Dysregulation of the autonomic nervous system (ANS) is commonly observed in various mental disorders, particularly when individuals engage in prolonged cognitive-emotional tasks that require ANS adjustment to workload. Although the understanding of the temporal dynamics of sympathetic and parasympathetic tones in obsessive-compulsive disorder (OCD) is limited, analyzing ANS reactions to cognitive-emotional workload could provide valuable insights into one of the underlying causes of OCD. This study investigated the temporal dynamics of heart rate (HR) and pupil area (PA) while participants with OCD and healthy volunteers solved antisaccade tasks, with affective pictures serving as central fixation stimuli. The data of 31 individuals with OCD and 30 healthy volunteers were included in the study, comprising three separate blocks, each lasting approximately 8 min. The results revealed an increase in sympathetic tone in the OCD group, with the most noticeable rise occurring during the middle part of each block, particularly during the presentation of negative stimuli. Healthy volunteers demonstrated adaptive temporal dynamics of HR and PA from the first block to the last block of tasks, whereas individuals with OCD exhibited fewer changes over time, suggesting a reduced adaptation of the ANS sympathetic tone to cognitive-emotional workload in OCD.

Long-range temporal correlations in resting state alpha oscillations in major depressive disorder and obsessive-compulsive disorder.

Mental disorders are a significant concern in contemporary society, with a pressing need to identify biological markers. Long-range temporal correlations (LRTC) of brain rhythms have been widespread in clinical cohort studies, especially in major depressive disorder (MDD). However, research on LRTC in obsessive-compulsive disorder (OCD) is severely limited. Given the high co-occurrence of OCD and MDD, we conducted a comparative LRTC investigation. We assumed that the LRTC patterns will allow us to compare measures of brain cortical balance of excitation and inhibition in OCD and MDD, which will be useful in the area of differential diagnosis. In this study, we used the 64-channel resting state EEG of 29 MDD participants, 26 OCD participants, and a control group of 37 volunteers. Detrended fluctuation analyzes was used to assess LRTC. Our results indicate that all scaling exponents of the three subject groups exhibited persistent LRTC of EEG oscillations. There was a tendency for LRTC to be higher in disorders than in controls, but statistically significant differences were found between the OCD and control groups in the entire frontal and left parietal occipital areas, and between the MDD and OCD groups in the middle and right frontal areas. We believe that these results indicate abnormalities in the inhibitory and excitatory neurotransmitter systems, predominantly affecting areas related to executive functions.

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.

Autistic Traits as Predictors of Increased Obsessive-Compulsive Disorder Severity: The Role of Inflexibility and Communication Impairment.

Due to similar manifestations, some authors have proposed a potential correlation between autism spectrum disorder (ASD) and obsessive-compulsive disorder (OCD). This link has long been recognized and debated, with some authors arguing that these disorders frequently occur comorbid but distinct while others believe they are part of the same spectrum. The aim of our study was to explore the prevalence and correlates of autistic traits in 55 OCD patients and 55 matched controls and to assess possible autistic dimensions predictive of higher OCD symptoms. All participants were assessed with the Obsessive-Compulsive Spectrum-Short Version (OBS-SV) and the Adult Autism Subthreshold Spectrum (AdAS Spectrum). The OCD group scored significantly higher in both questionnaires. Total OBS-SV scores and domains were significantly correlated with all AdAS Spectrum domains and total score. The AdAS Spectrum total, Verbal Communication and Inflexibility and adherence to routine domain scores were significant positive predictors of higher OBS-SV scores. Lastly, when two clusters of subjects (high and low autism) were determined, Inflexibility and adherence to routine domain presented the greatest influence in forming the clusters. Our findings support the association between OCD and autistic traits in the adult population, supporting the hypothesis of a neurodevelopmental basis for these psychiatric conditions.

Comparison of accidental findings of brain magnetic resonance imaging of patients with obsessive-compulsive disorder and healthy controls

BackgroundAbnormalities in brain magnetic resonance imaging (MRI) have been reported in drug-naive and chronic patients with obsessive-compulsive disorder (OCD). The Fazekas scale is a method used to categorize and grade the severity of white matter hyperintensities (WMH) in brain MRI. These lesions can be indicative of various neurological conditions, particularly small vessel disease or cerebrovascular pathology.MethodsBrain MRIs of patients followed up with the diagnosis of OCD were retrospectively analyzed. 58 OCD (36 females, 22 males) and 58 healthy controls (HC) (30 females, 28 males) were included in the study. Age, gender, and brain MRI findings of the participants were recorded.ResultsThe mean ages of the OCD and HC groups were 33.4 ± 10.6 and 35.9 ± 9.3. There was no difference between the groups in terms of mean ages and gender distribution (p = 0.180 and p = 0.260, accordingly). Generalized cerebral atrophy was more common in patients with OCD than in HC (p = 0.008). Fazekas grade 1 was detected in 17.2% of the patients with OCD and 1.7% of HC. Accordingly, it was significantly more common in Fazekas grade 1 OCD patients (p = 0.002). Fazekas grade 2 was detected in only 2 patient with OCD. CVI was present in 20.7% of the patients with OCD and 1.7% of HC. There was a significant difference between the groups regarding CVI (p = 0.001). Ethmoidal thickening was more common in patients with OCD than in HC (p = 0.004). The YBOCS scores and ages of OCD patients with Fazekas grade 1 and 2 were significantly higher than those of patients with Fazekas grade 0. Likewise, the YBOCS scores and ages of OCD patients with generalized cerebral atrophy were significantly higher than those of patients without atrophy.ConclusionIt is understood from the present study’s findings that CVI, a neurodevelopmental malformation, is more common in patients with OCD. Due to the potential relationship of this anomaly with neuronal migration, it would be appropriate to pay attention to OCD symptoms in individuals with CVI and to perform white matter examination on brain imaging. In future studies, Fazekas grade can be evaluated in drug-naive OCD patients, and data on the pre-disease period can be obtained.

Investigation of the effects of oxidative stress, inflammation on the pathway of tryptophan/kynurenine in OCD.

Recent studies have shown that the distribution of the tryptophan/kynurenine pathway (KP) plays a role in the development of obsessive-compulsive disorder (OCD). We aimed to reveal the relationship between CYP1A1 rs464903 and aryl hydrocarbon receptor (AhR) rs10249788 associated with the KP and interferon gamma (IFN γ) and oxidative stress in OCD. In our study, the serum and DNAs of 150 samples, including 100 OCD patients and 50 controls, were used. The activity of glutathione peroxidase (GSH-Px), and the levels of IFN γ, thiobarbituric acid reactive substances (TBARS), tryptophan, and kynurenine were determined by biochemical methods. AhR rs10249788 and cytochrome P450 family CYP1A1 rs4646903, which interact directly with the KP, were analysed by polymerase chain reaction followed by restriction fragment length polymorphism. P < 0.05 was considered statistically significant. There were no significant differences between groups in CYP1A1 rs4646903 and AhR rs10249788 while tryptophan and IFN γ were found to be higher in controls (p < 0.001, for both), and TBARS and indolamine-2,3-dioxygenase were found to be higher in OCD (p < 0.001, for both). There were significant correlations between IFN γ and TBARS and GSH-Px (p = 0.028, p = 0.020, respectively) in the OCD group. For the first time studied in OCD, it has been shown that IFN γ, tryptophan, oxidative stress parameters, and gene variants of CYP1A1 rs4646903 anAhR rs10249788 are shown effective on the KP.

Pathological Networking of Gray Matter Dendritic Density With Classic Brain Morphometries in OCD

The pathogenesis of obsessive-compulsive disorder (OCD) may involve altered dendritic morphology, but in vivo imaging of neurite morphology in OCD remains limited. Such changes must be interpreted functionally within the context of the multimodal neuroimaging approach to OCD. To examine whether dendritic morphology is altered in patients with OCD compared with healthy controls (HCs) and whether such alterations are associated with other brain structural metrics in pathological networks. This case-control study used cross-sectional data, including multimodal brain images and clinical symptom assessments, from 108 patients with OCD and 108 HCs from 2014 to 2017. Patients with OCD were recruited from Shanghai Mental Health Center, Shanghai, China, and HCs were recruited via advertisements. The OCD group comprised unmedicated adults with a Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV) diagnosis of OCD, while the HCs were adults without any DSM-IV diagnosis, matched for age, sex, and education level. Data were analyzed from September 2019 to April 2023. DSM-IV diagnosis of OCD. Multimodal brain imaging was used to compare neurite microstructure and classic morphometries between patients with OCD and HCs. The whole brain was searched to identify regions exhibiting altered morphology in patients with OCD and explore the interplay between the brain metrics representing these alterations. Brain-symptom correlations were analyzed, and the performance of different brain metric configurations were evaluated in distinguishing patients with OCD from HCs. Among 108 HCs (median [IQR] age, 26 [23-31] years; 50 [46%] female) and 108 patients with OCD (median [IQR] age, 26 [24-31] years; 46 [43%] female), patients with OCD exhibited deficient neurite density in the right lateral occipitoparietal regions (peak t = 3.821; P ≤ .04). Classic morphometries also revealed widely-distributed alterations in the brain (peak t = 4.852; maximum P = .04), including the prefrontal, medial parietal, cingulate, and fusiform cortices. These brain metrics were interconnected into a pathological brain network associated with OCD symptoms (global strength: HCs, 0.253; patients with OCD, 0.941; P = .046; structural difference, 0.572; P < .001). Additionally, the neurite density index exhibited high discriminatory power in distinguishing patients with OCD from HCs (accuracy, ≤76.85%), and the entire pathological brain network also exhibited excellent discriminative classification properties (accuracy, ≤82.87%). The findings of this case-control study underscore the utility of in vivo imaging of gray matter dendritic density in future OCD research and the development of neuroimaging-based biomarkers. They also endorse the concept of connectopathy, providing a potential framework for interpreting the associations among various OCD symptom-related morphological anomalies.

Dorsal Striatal Functional Connectivity and Repetitive Behavior Dimensions in Children and Youths With Neurodevelopmental Disorders

BackgroundImpairing repetitive behaviors are one of the core diagnostic symptoms in autism spectrum disorder and obsessive-compulsive disorder, but they also manifest in attention-deficit/hyperactivity disorder. Although the dorsal striatal circuit has been implicated in repetitive behaviors, extensive heterogeneity in and cross-diagnostic manifestations of these behaviors have suggested phenotypic and likely neurobiological heterogeneity across neurodevelopmental disorders (NDDs). MethodsIntrinsic dorsal striatal functional connectivity was examined in 3 NDDs (autism spectrum disorder, obsessive-compulsive disorder, and attention-deficit/hyperactivity disorder) and typically developing control participants in a large single-cohort sample (N = 412). To learn how diagnostic labels and overlapping behaviors manifest in dorsal striatal functional connectivity measured with functional magnetic resonance imaging, the main and interaction effects of diagnosis and behavior were examined in 8 models (2 seed functional connectivity [caudate and putamen] × 4 sub-behavioral domains [sameness/ritualistic, self-injury, stereotypy, and compulsions]). ResultsThe obsessive-compulsive disorder group demonstrated distinctive patterns in visual and visuomotor coordination regions compared with the other diagnostic groups. Lower-order repetitive behaviors (self-injury and stereotypy) manifesting across all participants were implicated in regions involved in motor and cognitive control, although the findings did not survive effects of multiple comparisons, suggesting heterogeneity in these behavioral domains. An interaction between self-injurious behavior and an attention-deficit/hyperactivity disorder diagnosis were observed on caudate-cerebellum functional connectivity. ConclusionsThese findings confirmed high heterogeneity and overlapping behavioral manifestations in NDDs and their complex underlying neural mechanisms. A call for diagnosis-free symptom measures that can capture not only observable symptoms and severity across NDDs but also the underlying functions and motivations of such behaviors across diagnoses is needed.

Neural correlates of risk taking in patients with obsessive-compulsive disorder during risky decision-making

BackgroundThe risk preference during decision-making and the neural substrates involved in patients with obsessive-compulsive disorder (OCD) remained unclear. The current study was designed to evaluate the risk-taking behaviors during decision-making and neural correlates in patients with OCD, thereby providing a deeper insight into their impaired decision-making function. MethodsFifty-one patients with OCD and 50 healthy controls (HCs) were included in this study. All subjects underwent functional magnetic resonance imaging (fMRI) scans while completing the Balloon Analog Risk Task (BART). The behavior indicator and cognitive model parameter in BART, as well as the neural correlates of risk-taking behaviors were analyzed. ResultsCompared to HCs, the OCD group performed a significantly higher level of risk-averse behaviors, and the cognitive model parameter revealed that patients with OCD tend to decrease their risk level after receiving negative feedbacks during BART. The fMRI results based on prespecified brain regions showed that the OCD group exhibited significantly decreased activation modulated by risk levels both in the left and right insula. LimitationsThe effect of medication in this study could not be completely ruled out, and it is difficult to temporally separate different states of decision-making in the BART. ConclusionsIndividuals with OCD exhibited a higher level of risk aversion during decision-making process, and the dysfunction of the insula may be the neural basis of the increased risk aversion in OCD. These findings provide further insights into the mechanism of risk aversion and impaired decision-making function in individuals with OCD.

Regional homogeneity in patients with obsessive–compulsive disorder and depression: A resting state functional magnetic resonance imaging study

ObjectiveTo explore the brain functional impairment of patients with obsessive–compulsive disorder (OCD) with and without depressive symptoms and analyze the correlation between the degree of impairment and the severity of symptoms. MethodFourteen patients with OCD who met the ICD-10 diagnostic criteria for OCD were included. The group having OCD with depression (OCDd) consisted of 15 patients, and 17 healthy controls (HC) matched for age and education were also included. The Yale–Brown OCD Scale (Y-BOCS) and the 24-item Hamilton Assessment of Depression Scale (HAMD) were administered to the OCD and OCDd groups. Resting-state functional brain magnetic resonance imaging was performed in the three groups of participants. ResultThe OCDd group had lower scores on the HAMD, Y-BOCS, and obsessive–compulsive thinking subscales compared with the OCD group (P < 0.05). The scores on the OCDd subscale were negatively correlated with the HAMD scores (R = − 0.568, P = 0.027). The OCDd group had higher regional homogeneity (ReHo) values in the lingual gyrus than the OCD group. The OCDd group had higher ReHo values in the lingual gyrus than the HC group, and the OCDd group had higher ReHo values than the HC group. These differences were statistically significant (P < 0.05). After correction for multiple comparisons, significant difference was observed between the OCDd and HC groups (P＜0.05). In the OCD group, the ReHo value of the lingual gyrus was negatively correlated with the Y-BOCS total score and the compulsive behavior subscale score (R = − 0.609, −0.552; P = 0.016, 0.033). ConclusionAbnormal ReHo values in the lingual gyrus and right medial superior frontal gyrus were found in the patients with OCDd. In the OCDd group, the ReHo values of the lingual gyrus were negatively correlated with the scores on the Y-BOCS total and obsessive–compulsive subscales, suggesting that abnormal local coherence of the lingual gyrus may be related to the severity of OCD.

Investigating the effect of obsessive-compulsive disorder on clinical symptoms of temporomandibular joint disorders.

Temporomandibular disorders (TMD) are a group of clinical conditions involving muscles of mastication, temporomandibular joint (TMJ), and related structures or both. TMD is characterized by facial pain in TMJ and muscles of mastication, limitation or deviation of jaw movement, and TMJ sounds during jaw movement and function. The highest risk of TMD prevalence is between 18 and 24 years, and a relationship is between chronic TMD and psychological disorders such as stress and depression. The knowledge of the function of this joint and those with TMD symptoms when visiting the dentist will help to provide an ideal treatment plan for the patient. Therefore, if the therapist is familiar with the various etiological factors of this disorder, he will provide better treatment, especially if the simultaneous effect of psychological factors such as stress and obsessive-compulsive disorder (OCD) along with occlusal factors such as posterior cross-bite, overjet, and overbite is measured, it can be a valuable guide for clinicians. In this study, 385 patients were examined by DASS42 and Maudsley's test and classified into normal, with stress, and stress plus OCD groups. TMJ was examined for each of them by the TMD-RDC test. The presence or absence of TMD was noted in their file. The prevalence of TMD was 20.7% in the normal group, 30.70% in the stress group, and 44.68% in the stress and OCD group. After analyzing the data by SPSS 24 and performing analysis of variance and Duncan tests, no significant difference was found between the probability of TMD in normal and stressed groups, but the stress and OCD group has a higher chance of TMD. Although the co-occurrence of stress and OCD is associated with the prevalence of TMD, it cannot be considered a cause of TMD.

Spectroscopic abnormalities in the pregenual anterior cingulate cortex in obsessive-compulsive disorder using proton magnetic resonance spectroscopy: a controlled study

BackgroundThe main aim of the present study is to determine the role of metabolites observed using proton magnetic resonance spectroscopy (1H-MRS) in obsessive-compulsive disorder (OCD). As the literature describing biochemical changes in OCD yields conflicting results, we focused on accurate metabolite quantification of total N-acetyl aspartate (tNAA), total creatine (tCr), total choline-containing compounds (tCh), and myo-inositol (mI) in the anterior cingulate cortex (ACC) to capture the small metabolic changes between OCD patients and controls and between OCD patients with and without medication.MethodsIn total 46 patients with OCD and 46 healthy controls (HC) matched for age and sex were included in the study. The severity of symptoms in the OCD was evaluated on the day of magnetic resonance imaging (MRI) using the Yale-Brown Obsessive-Compulsive Scale (YBOCS). Subjects underwent 1H-MRS from the pregenual ACC (pgACC) region to calculate concentrations of tNAA, tCr, tCho, and mI. Twenty-eight OCD and 28 HC subjects were included in the statistical analysis. We compared differences between groups for all selected metabolites and in OCD patients we analyzed the relationship between metabolite levels and symptom severity, medication status, age, and the duration of illness.ResultsSignificant decreases in tCr (U = 253.00, p = 0.022) and mI (U = 197.00, p = 0.001) in the pgACC were observed in the OCD group. No statistically significant differences were found in tNAA and tCho levels; however, tCho revealed a trend towards lower concentrations in OCD patients (U = 278.00, p = 0.062). Metabolic concentrations showed no significant correlations with the age and duration of illness. The correlation statistics found a significant negative correlation between tCr levels and YBOCS compulsions subscale (cor = -0.380, p = 0.046). tCho and YBOCS compulsions subscale showed a trend towards a negative correlation (cor = -0.351, p = 0.067). Analysis of subgroups with or without medication showed no differences.ConclusionsPatients with OCD present metabolic disruption in the pgACC. The decrease in tCr shows an important relationship with OCD symptomatology. tCr as a marker of cerebral bioenergetics may also be considered as a biomarker of the severity of compulsions. The study failed to prove that metabolic changes correlate with the medication status or the duration of illness. It seems that a disruption in the balance between these metabolites and their transmission may play a role in the pathophysiology of OCD.

Decision-making deficits in obsessive-compulsive disorder are associated with abnormality of recency and response consistency parameter in prospect valence learning model.

Patients with obsessive-compulsive disorder (OCD) have deficits in decision-making in the Iowa Gambling Task (IGT). However, no study has investigated the parameters of the prospect valence learning (PVL) model in the IGT for OCD. This study aimed to investigate deficits in decision-making in OCD using the PVL model and identify whether the parameters of the PVL model were associated with obsessive-compulsive severity. Forty-seven medication-free patients with OCD were compared with 47 healthy controls (HCs). Decision-making was measured using the total net and block net scores of the IGT. A PVL model with a decay-reinforcement learning rule (PVL-DecayRI) was used to investigate the parameters of the model. Correlation analysis was conducted between each parameter of the PVL-DecayRL and obsessive-compulsive symptoms. The total net score of patients with OCD was significantly lower than that of the HCs. The block net scores of the OCD group did not differ across the five blocks, whereas in the HCs, the fifth block net score was significantly higher than the block net scores of the first and second blocks. The values of the recency and response consistency parameters of the PVL-DecayRI in patients with OCD were significantly lower than those in HCs. The recency parameter positively correlated with the Y-BOCS obsessive score. Meanwhile, there was no correlation between consistency parameter values and symptom severity in OCD. Our detailed analysis of the decision-making deficit in OCD suggests that the most recent outcome has a small influence on the expectancy of prospect valence, as indicated by the lower recency parameter, and is characterized by more impulsive choices, as indicated by the lower consistency parameter.

Microbiome analysis of circulating bacterial extracellular vesicles in obsessive-compulsive disorder.

The present study examined the microbiome abundance and composition of drug-naïve or drug-free patients with obsessive-compulsive disorder (OCD) compared to healthy controls. In addition, in the OCD group, the microbiome composition was compared between early-onset and late-onset OCD. Serum samples were collected from 89 patients with OCD and 107 age- and sex-matched healthy controls. Bacterial DNA was isolated from bacteria-derived extracellular vesicles in serum and then amplified and quantified using primers specific to the V3-V4 hypervariable region of the 16S rDNA gene. The 16S rRNA gene amplicon sequencing was performed. The pooled estimate showed that alpha diversity was significantly reduced in patients with OCD compared to that in healthy controls (pShannon = 0.00015). In addition, a statistically significant difference was observed in beta diversity between patients with OCD and healthy controls at the order (p = 0.012), family (p = 0.003), genus (p < 0.001), and species (p = 0.005) levels. In the microbiome composition, Pseudomonas, Caulobacteraceae(f), Streptococcus, Novosphingobium, and Enhydrobacter at the genus level were significantly less prevalent in patients with OCD than in controls. In addition, among patients with OCD, the microbial composition in the early-onset versus late-onset types was significantly different with respect to the genera Corynebacterium and Pelomonas. The present study showed an aberrant microbiome in patients with OCD, suggesting a role of the microbiota-brain interaction in the pathophysiology of OCD. Further longitudinal studies with larger sample sizes adjusting for various confounders are warranted. This article is protected by copyright. All rights reserved.

Delusional beliefs in adolescents with anorexia nervosa, obsessive-compulsive disorder, or first-episode psychosis: A comparative study

Delusional thinking is a key symptom of first-episode psychosis (FEP), but it has also been studied in obsessive-compulsive disorder (OCD) and anorexia nervosa (AN). This study aimed to analyze the psychometric properties of the Brown Assessment of Beliefs Scale (BABS) in a sample of adolescents diagnosed with a FEP, AN, or OCD, and to compare delusional thinking among the three samples. The sample comprised 60 patients in three groups of 20 diagnosed with OCD, AN, or FEP. Participants underwent assessment by diagnostic interview, the BABS scale, and a measure of depressive symptomatology. Specific instruments were also used to assess the main symptomatology of each disorder. The BABS had good internal consistency, and high validity and reliability. The OCD group scored significantly lower than the other two groups in all scale items except for items 4 (fixation of ideas), 6 (insight), and 7 (delusions of reference). A significant difference only existed between the AN and FEP groups for item 7 (delusions of reference). The BABS scale is a valid and reliable tool for assessing delusionality in adolescents diagnosed with OCD, AN, or FEP, with evidence of marked differences between the disorders. Assessing these symptoms could influence management, helping to improve treatment adherence and prognosis.