Enhanced Avoidance Habits in Obsessive-Compulsive Disorder

Reversal Learning as a Neuropsychological Indicator for the Neuropathology of Obsessive Compulsive Disorder? A Behavioral Study

The aim of this study is to determine whether the levels of zonulin and occludin, tight junctions (TJ) proteins in the intestinal epithelium, will differ between obsessive compulsive disorder (OCD) patients and healthy controls. We also intended to investigate whether these would vary in OCD patients with and without major depressive disorder (MDD) comorbidity and in comparison with healthy controls. Sixty patients diagnosed with OCD and 30 healthy controls were included in the study. The cases were administered the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Hamilton Depression Rating Scale (HDRS). The patients were divided into two subgroups based on their HDRS scores and presence of MDD comorbidity. Zonulin and occludin levels were measured using the ELISA method. The research was carried out between April 2021 and October 2021. Zonulin and occludin levels were significantly higher in the OCD patient group than in the control group (p<0.001). The levels of both were also significantly higher in the OCD patients with MDD comorbidity (OCD+MDD) compared to those without MDD (OCD-MDD) (p<0.001). Zonulin and occludin levels also rose significantly as disease severity increased in the OCD patient group (respectively; p<0.001, p=0.001). The levels of both increased in line with the severity of depression based on HDRS scores in the OCD+MDD group (p<0.001). A positive correlation was determined between the duration of OCD and zonulin and occludin levels. Evaluation of the entire OCD group revealed a moderate positive correlation between Y-BOCS and HDRS scores and zonulin and occludin. Zonulin and occludin levels in this research were significantly higher in the patients with OCD than in the healthy controls. That elevation was positively correlated with disease duration and severity, and the increase was significantly more pronounced in OCD with MDD comorbidity. These findings point to a possible disorder in the intestinal barrier and blood-brain barrier in OCD patients.

Objective To investigate the regulatory effect of cognitive behavioral therapy (CBT) on the functional connectivity of cognitive control network in untreated obsessive-compulsive disorder (OCD) patients, so as to provide evidence for understanding the neurobiological mechanism of CBT. Methods A total of 45 OCD patients and 45 matched normal controls were recruited at the outpatient clinic in Beijing Anding Hospital. Four therapists provided 14 times of CBT treatment for OCD patients. All subjects underwent clinical symptom assessment and magnetic resonance imaging at baseline and at the end of 12 weeks. The clinical symptoms were assessed by the psychiatrists using Y-BOCS, HAMD17 and HAMA. The clinical symptoms of OCD patients before and after CBT treatment were compared. The GRETNA software package was used to preprocess the resting-state fMRI data. The whole brain function network was constructed with the template of Power 264 functional brain area as the network node. The function connection intensity outside the cognitive control network was calculated, and the function connection of 2 groups of brain networks at two timepoints were compared by repeated measurement of variance analysis. Results A total of 41 patients completed CBT. The scores of obsessive-compulsive symptoms, anxiety symptoms and depressive symptoms decreased at the end of 12th week, of which 32 patients were improved (Y-BOCS reduction ≥35%). Single factor repeated analysis of variance and post hoc tests were performed between patients with improvement and normal controls. At baseline, the functional connection between the cingulo-opercular network and the salience network of OCD patients was lower than that of the normal control (0.172±0.060 vs. 0.215±0.076, t=1.731, P=0.040), it increased after treatment (0.186±0.171 vs. 0.172±0.060, t=2.480, P=0.010). At baseline, the functional connection of cingulo-opercular network and subcortical network in OCD patients was lower than that of normal control (0.119±0.081 vs. 0.129±0.070, t=1.640, P=0.040), and it increased after treatment (0.130±0.161 vs. 0.119±0.081, t=2.421, P=0.020). At baseline, the functional connection between the frontal-parietal network and subcortical network was lower than that of normal controls (-0.004±0.039 vs. 0.021±0.054, t=2.280, P=0.020), and it increased after treatment (0.020±0.042 vs.-0.004±0.039, t=-2.300 P=0.020). Conclusions CBT could effectively improve obsessive-compulsive symptoms accompanying with improvement of the external functional connectivity of cognitive control network in OCD patients. Key words: Obsessive-compulsive disorder; Cognitive therapy; Cognitive control network; Functional connectivity

Chronic tics and Tourette syndrome in patients with obsessive–compulsive disorder

Background and AimsRecent studies have challenged the anxiety-avoidance model of obsessive–compulsive disorder (OCD), linking OCD to impulsivity, risky-decision-making and reward-system dysfunction, which can also be found in addiction and might support the conceptualization of OCD as a behavioral addiction. Here, we conducted an exploratory investigation of the behavioral addiction model of OCD by assessing whether OCD patients are more impulsive, have impaired decision-making, and biased probabilistic reasoning, three core dimensions of addiction, in a sample of OCD patients and healthy controls.MethodsWe assessed these dimensions on 38 OCD patients and 39 healthy controls with the Barratt Impulsiveness Scale (BIS-11), the Iowa Gambling Task (IGT) and the Beads Task.ResultsOCD patients had significantly higher BIS-11 scores than controls, in particular on the cognitive subscales. They performed significantly worse than controls on the IGT preferring immediate reward despite negative future consequences, and did not learn from losses. Finally, OCD patients demonstrated biased probabilistic reasoning as reflected by significantly fewer draws to decision than controls on the Beads Task.ConclusionsOCD patients are more impulsive than controls and demonstrate risky decision-making and biased probabilistic reasoning. These results might suggest that other conceptualizations of OCD, such as the behavioral addiction model, may be more suitable than the anxiety-avoidance one. However, further studies directly comparing OCD and behavioral addiction patients are needed in order to scrutinize this model.

In economics, models of decision-making under risk are widely investigated. Since many empirical studies have shown patterns in choice behavior that classical models fail to predict, several descriptive theories have been developed. Due to an evident phenotypic heterogeneity, obsessive compulsive disorder (OCD) patients have shown a general deficit in decision making when compared to healthy control subjects (HCs). However, the direction for impairment in decision-making in OCD patients is still unclear. Hence, bridging decision-making models widely used in the economic literature with mental health research may improve the understanding of preference relations in severe patients, and may enhance intervention designs. We investigate the behavior of OCD patients with respect to HCs by means of decision making economic models within a typical neuropsychological setting, such as the Cambridge Gambling Task. In this task subjects have to decide the amount of their initial wealth to invest in each risky decision. To account for heterogenous preferences, we have analyzed the micro-level data for a more informative analysis of the choices made by the subjects. We consider two influential models in economics: the expected value (EV), which assumes risk neutrality, and a multiple reference points model, an alternative formulation of Disappointment theory. We find evidence that (medicated) OCD patients are more consistent with EV than HCs. The former appear to be more risk neutral, namely, less sensitive to risk than HCs. They also seem to base their decisions on disappointment avoidance less than HCs.

Capacity to Delay Reward Differentiates Obsessive-Compulsive Disorder and Obsessive-Compulsive Personality Disorder

Obsessive compulsive disorder (OCD) is a serious mental disease highly associated with the dysfunctional dynamics of brain networks. The default mode network (DMN) is an essential brain network responding to various cognitive functions, which has been reported the abnormality in OCD patients. However, the underlying evolutions of temporal-spatial neurodynamics in fast-changing DMN activity of OCD remains largely unclear. In the present work, we tried to address this issue by tracking the neurodynamic structure of electrophysiological DMN activity in OCD patients during the resting state. To achieve this purpose, we reconstructed the DMN source activity from the scalp EEG signal with the exact low-resolution brain electromagnetic tomography (LORETA) algorithm, and applied coactive micropattern (CAMP) analysis developed by our previous studies to characterize DMN dynamics. We observed three CAMPs with distinct spatial structures in DMN dynamics for the normal subjects, while there were four different CAMPs in OCD patients. More interestingly, the temporal features of CAMPs which displayed similar spatial structures in two groups were also significantly altered in OCD patients compared with those in normal subjects, implying an abnormal DMN dynamic structure for OCD. Moreover, stronger DMN source connectivity in different CAMP networks emerged in OCD patients, where the posterior cingulate cortex and frontal cortex might be two hub regions with more increased connectivity. Overall, our results showed pathological alterations in the dynamic configuration of the DMN in OCD patients and revealed the neural brain network mechanism for OCD. All these findings could deepen our understanding of the neural pathology of OCD and might provide potential electrophysiological markers for diagnosing OCD patients clinically.

Obsessive-compulsive disorder (OCD) is a common psychiatric illness characterised by recurrent, intrusive thoughts and repetitive, stereotyped behaviours. There is converging evidence that OCD is associated with a specific cognitive deficit related to organising and manipulating information in working memory. There is also evidence that OCD is associated with certain pre-morbid personality traits. However, further research is needed to elucidate whether these cognitive deficits and personality traits are specific to OCD or are present in other anxiety disorders and/or individuals with sub-clinical levels of obsessive-compulsive (OC) symptoms. In this thesis, 20 OCD patients were compared to 20 patients with panic disorder, 20 subjects with sub-clinical OC symptoms and 20 healthy control subjects on tests of working memory and the Five-Factor Model of personality. To measure different aspects of working memory, participants completed three delayed matching-to-sample (DMS) tasks and two continuous performance working memory tasks (n-back tasks). The DMS tasks assessed the ability to actively maintain different types of information in working memory (irregular objects; geometric objects; spatial locations). The n-back tasks assessed the ability to update and temporally order verbal and spatial stimuli in working memory. The OCD patients were less accurate than the healthy control subjects on the memory trials of the spatial DMS task, the 3- back trials of the spatial n-back task, and the 2-back and 3-back trials of the verbal n-back task. The OCD patients were also less accurate than patients with panic disorder and sub-clinical OC subjects on the verbal 3-back task. The results indicated that OCD patients were impaired on cognitive tasks requiring the maintenance of spatial stimuli and the updating and temporal ordering of verbal and spatial stimuli in working memory. The OCD patients were not impaired on tasks requiring the maintenance of object information in working memory. To measure normal personality traits, subjects completed the Revised NEO Personality Inventory (NEO PIR). Compared to healthy controls, OCD patients reported being highly emotional and introverted, less open to new experiences, and lacking confidence in their own abilities. The OCD patients were similar to the panic disorder patients on most of the domains and facets of the NEO PI-R, however, they were distinguished by their lower openness to experiencing new activities, and being less diligent and purposeful. Compared to the sub-clinical OC subjects, OCD patients reported being more prone to feelings of depression, more vulnerable to stress, less likely to experience positive emotions, more humble and sincere and less able to carry tasks through to completion. Overall, the thesis provided further evidence that OCD patients are impaired on cognitive tasks requiring the organisation and manipulation of information in working memory. However, it is still unclear whether this deficit arises due to capacity constraints being exceeded in working memory systems, or some other executive dysfunction such as excessive error monitoring. Future research, combining neuropsychological testing with neuroimaging techniques, is required to better understand the neural mechanisms underlying the impaired performance of OCD patients on tests of working memory. The present thesis also found that normal personality traits - as measured by the NEO PI-R - were able to distinguish OCD patients from healthy controls, patients with panic disorder and individuals with sub-clinical levels of OC symptoms. The results have implications for sub-clinical OC research and the clinical management of OCD.

Obsessive-compulsive disorder (OCD) is characterized by recurrent, persistent thoughts and repetitive behaviors causing stress and anxiety. In the associative learning model of OCD, mechanisms of fear extinction are supposed to partly underlie symptom development, maintenance and treatment of OCD, proposing that OCD patients suffer from rigid memory associations and inhibitory learning deficits. To test these assumptions, previous studies have used skin conductance and subjective ratings as readouts in fear conditioning paradigms, finding impaired fear extinction learning, impaired fear extinction recall or no differences between individuals with OCD and healthy controls. Against this heterogeneous background, we tested fear acquisition and extinction in 37 OCD patients and 56 healthy controls, employing skin conductance as well as pupillometry and startle electromyography. Extinction recall was also included in a subsample. We did not observe differences between groups in any of the task phases, except a trend toward higher startle amplitudes during extinction for OCD. Overall, sensitive readouts such as pupillometry and startle responses did not provide evidence for moderate-to-large inhibitory learning deficits using classical fear conditioning, challenging the assumption of generically impaired extinction learning and memory in OCD.

Panic disorder and obsessive compulsive disorder in a hyperventilation challenge test

Lateralized readiness potentials and sensorimotor activity in adults with obsessive-compulsive disorder

Electrophysiological sleep features and inhibitory control functions in patients with obsessive-compulsive disorder.

Objective To explore the association of peripheral catechol-O-methyl-transferase (COMT)gene expression and obsessive-compulsive disorder(OCD)in Han Chinese.Methods Peripheral blood samples were collected from individuals with OCD(n=35)and age-and sex-matched healthy subjects (n=31).Relative COMT gene expression levels were examined with real-time quantitative reverse transcription PCR in peripheral blood of all the subjects.Structured clinical interview for the 4th Edition of Diagnostic and Statistical Manual of Mental Disorder axisⅡ(SCID-Ⅱ)was used to assess the co-morbidity of OCD and obsessive-compulsive personality disorders(OCPD).The Yale-Brown Obsessive-Compulsive Scale(Y-BOCS)was used to evaluate the severity of obsessive compulsive symptoms.Results The COMT gene expression levels were significantly decreased in the OCD group compared with healthy control group (t=2.56,P＜0.05).The OCD patients showed a 32%down-regulation of COMT gene expression.A significant lower COMT gene expression was observed in non-OCPD patients(n=15)in comparison with healthy controls(t=2.41.P＜0.05),while there was,no significant difference between OCPD patients (n=20)and healthy controls(t=1.50,P＞0.05).The rates of COMT gene expression down-regulation in OCD patients with OCPD and ones without OCPD were 14%and 56%respectively.There was no significant correlation between COMT expression level and the Y-BOCS score(r=0.09,P=0.62).Conclusions These results suggest that COMT gene expression down-regulation is associated with OCD,and the OCD patients with and without OCPD may have different genetic background. Key words: Obsessive-compulsive disorder; Compulsive personality disorder; Catechol Omethyl transferase; Gene expression

Background: Despite the theoretical and clinical relevance of psychopathological dimensions in obsessive-compulsive disorder (OCD), no studies to date have investigated their possible association with obsession subtypes. Thus, we aimed to examine whether, in OCD patients, anger and other psychopathological dimensions are associated with specific obsession subtypes. Methods: We consecutively recruited 57 first-visit OCD patients (66.7% female, mean age 34 years) at our Psychiatric Outpatient Clinic. We used the point biserial coefficient (r_pbi) to measure the correlation between psychopathological dimensions and obsession subtypes. Results: We found significant correlations (p < 0.05) between the following: (1) anger/aggressiveness dimension and aggressive, contamination, and sexual obsessions; (2) apprehension/fear dimension and contamination, religious, and somatic obsessions; (3) sadness/demoralization dimension and contamination and somatic obsessions; (4) impulsivity dimension and aggressive and sexual obsessions, and (5) somatic concern/somatization dimension and contamination and somatic obsessions. We also found that OCD patients with comorbid obsessive-compulsive personality disorder - but not schizotypal or histrionic disorders - showed higher levels (p < 0.05) of obsessiveness/iterativity and anger/aggressiveness than OCD patients without the personality disorder. Conclusions: Anger and other psychopathological dimensions seem to be linked with specific obsession subtypes in OCD patients, suggesting an association between these dimensions and OCD.