The neuropsychology of adult obsessive–compulsive disorder: A meta-analysis

The deer mouse (Peromyscus maniculatus bairdii) as a model organism to explore the naturalistic psychobiological mechanisms contributing to compulsive-like rigidity: A narrative overview of advances and opportunities

Deer mice (Peromyscus maniculatus bairdii), a wildtype species native to North America, have been investigated for their spontaneous compulsive-like behaviour. The repetitive and persistence nature of three unique compulsive-like phenotypes in deer mice, i.e., high stereotypy (HS), large nesting behaviour (LNB) and high marble burying (HMB), are characterized by behavioural and cognitive rigidity. In this narrative review, we summarize key advances in the model's application to study obsessive-compulsive disorder (OCD), emphasizing how it may be used to investigate neurobiological and neurocognitive aspects of rigidity. Indeed, deer mice provide the field with a unique naturalistic and spontaneous model system of behavioural and cognitive rigidity that is useful for investigating the psychobiological mechanisms that underpin a range of compulsive-like phenotypes. Throughout the review, we highlight new opportunities for future research.

Harm avoidance and incompleteness core motivations in obsessive-compulsive disorder: validation of the Farsi version of the Obsessive-Compulsive Trait Core Dimensions Questionnaire (F-OC-TCDQ) in Iran

BACKGROUND

Attention to the heterogeneous manifestations of obsessive-compulsive symptoms observed in clinical and nonclinical populations has motivated researchers to use tools to identify homogeneous subgroups of obsessive-compulsive disorder (OCD) patients. The Obsessive-Compulsive Trait Core Dimensions Questionnaire (OC-TCDQ) is used to evaluate two motivational dimensions of OCD (harm avoidance (HA) and incompleteness (INC)), which has been developed in recent years based on the core dimensions model, and to classify homogeneous subgroups. This study aimed to validate the Farsi version of the OC-TCDQ in Iran.

METHODS

The psychometric properties of the OC-TCDQ were tested in two clinical samples (209 patients with OCD) and nonclinical samples (209 participants without OCD). Confirmatory factor analysis (CFA) was conducted to test the two-factor structure. The measurement invariance between the clinical and nonclinical groups was evaluated. Reliability was tested using Cronbach's alpha, split-half, and retesting (two-week intervals). Convergent and divergent validity were analysed with Pearson's correlation and the incremental validity of this scale in predicting Yale-Brown Obsession Scale (Y-BOCS) and Beck Anxiety Inventory (BAI) scores using hierarchical regression analysis. The discriminant validity of the two clinical and nonclinical groups was investigated with a t-test.

RESULTS

Similar to the original version, the CFA showed a good fit for the two-factor structure. The invariance of measurement between samples, good internal consistency and retest reliability, and convergent and divergent validity of this scale were confirmed. The results of hierarchical regression analysis indicated the increasing validity of this scale in predicting the Y-BOCS and BAI compared to the OBQ-44 (p < 0.05), and comparing the scores of two groups with and without OCD indicated its discriminant validity (p < 0.01).

CONCLUSION

These findings show that the Farsi-OC-TCDQ is a valid tool for evaluating the motivational dimensions of harm avoidance and incompleteness in Iranian individuals with and without OCD, and it allows us to compare the scores across groups.

Neurocognitive performance in the context of acute symptom reduction in OCD: Treatment effects and the impact of BDNF

BACKGROUND

Obsessive-compulsive disorder (OCD) has been associated with neurocognitive impairments. The present study examined the effect of treatment on neurocognitive performance in OCD and the relationship between neurocognitive change and symptom change. The present study also examined polymorphisms influencing brain derived neurotrophic factor (BDNF) as predictors of neurocognitive change.

METHOD

Treatment-seeking participants with OCD (N = 125) were assigned to cognitive behavioural therapy (CBT) alone, CBT combined with regular physical exercise, exercise alone, or a waitlist control group. Measures of OCD symptom severity and a neuropsychological battery were completed pre- and post-treatment. Blood or saliva samples were used to genotype the BDNF Val66Met polymorphism.

RESULTS

OCD symptom severity was not cross-sectionally associated with neurocognitive performance. Several neurocognitive measures improved over treatment. The BDNF Val66Met polymorphism was significantly associated with worse performance on the Stroop test but did not significantly predict change in neurocognitive performance over time.

LIMITATIONS

Limitations include lack of a healthy control group.

CONCLUSION

Improvement in neurocognitive performance corresponded to symptomatic improvement and was independent of the BDNF Val66Met genotype.

Neuropsychological Deficits in Disordered Screen Use Behaviours: A Systematic Review and Meta-analysis

Over the last few decades, excessive and disordered screen use has become more prevalent, prompting investigations into its associated consequences. The extent to which disordered screen use behaviours impact neuropsychological functioning has been reportedly mixed and at times inconsistent. This review sought to synthesise the literature and estimate the magnitude of overall cognitive impairment across a wide range of disordered screen use behaviours. We also sought to determine the cognitive domains most impacted, and whether the observed impairments were moderated by the classification of screen-related behaviours (i.e., Internet or gaming) or the format of cognitive test administration (i.e., paper-and-pencil or computerised). A systematic search of databases (Embase, PsycINFO, MEDLINE) identified 43 cross-sectional articles that assessed neuropsychological performance in disordered screen use populations, 34 of which were included in the meta-analysis. A random-effects meta-analysis revealed significant small/medium (g = .38) cognitive deficits for individuals with disordered screen use behaviours relative to controls. The most affected cognitive domain with a significant medium effect size (g = .50) was attention and focus followed by a significant reduction in executive functioning (g = .31). The classification of disordered screen use behaviours into Internet or gaming categories or the format of cognitive testing did not moderate these deficits. Additionally, excluding disordered social media use in an exploratory analysis had little effect on the observed outcomes. This study highlights a number of methodological considerations that may have contributed to disparate findings and shows that disordered screen use can significantly impact cognitive performance. Recommendations for future research are also discussed. Data for this study can be found at https://osf.io/upeha/ .

From Cognitive Function to Treatment Efficacy in Obsessive-Compulsive Disorder: Insights from a Multidimensional Meta-Analytic Approach

Meta-analysis is a statistical tool used to combine and synthesise the results of multiple independent studies on a particular topic. To this end, researchers isolate important moderators and mediators to investigate their influence on outcomes. This paper introduces a novel approach to meta-analysis, known as multidimensional meta-analysis (mi-MA), to study memory performance in those with obsessive-compulsive disorder (OCD). Unlike traditional meta-analyses, mi-MA allows researchers to extract multiple data points (e.g., using different measures) from single studies and groups of participants, facilitating the exploration of relationships between various moderators while avoiding multicollinearity issues. Therefore, in the first instance, we outline the use of the mi-MA approach to quantify the impact of complex models of memory performance in individuals with OCD. This approach provides novel insights into the complex relationship between various factors affecting memory in people with OCD. By showcasing the effectiveness of mi-MA in analysing intricate data and modelling complex phenomena, the paper establishes it as a valuable tool for researchers exploring multifaceted phenomena, both within OCD research and beyond.

EEG microstates are associated with the improvement of obsessive-compulsive symptoms after transcranial direct current stimulation

BACKGROUND

Transcranial direct current stimulation (tDCS) is a safe, accessible, and promising therapeutic approach for obsessive-compulsive disorder (OCD).

AIMS

This study aimed to evaluate the effect of tDCS on electroencephalography (EEG) microstates and identify potential biomarkers to predict efficacy.

METHODS

A total of 24 individuals diagnosed with OCD underwent ten sessions of tDCS targeting the orbitofrontal cortex, while 27 healthy individuals were included as controls. Microstates A, B, C, and D were extracted before and after tDCS. A comparative analysis of microstate metrics was performed between the OCD and the healthy control groups, as well as within the OCD group before and after tDCS. Multiple linear regression analysis was performed to identify potential biomarkers of tDCS.

RESULTS

Comparison to healthy controls, the OCD group exhibited a significantly reduced duration of microstate A and increased occurrence of microstate D. The transition between microstates A and C was significantly different between patients with OCD and healthy controls and was no longer observed following tDCS. Multiple linear regression analysis revealed that the duration of microstate C was associated with an improvement OCD symptom after tDCS.

CONCLUSIONS

The results revealed an aberrant large-scale EEG brain network that could be modulated by tDCS. In particular, the duration of EEG microstate C may be a neurophysiological characteristic associated with the therapeutic effects of tDCS on OCD.

Atypical neurocognitive functioning in children and adolescents with obsessive-compulsive disorder (OCD)

Atypical neurocognitive functioning has been found in adult patients with obsessive-compulsive disorder (OCD). However, little work has been done in children and adolescents with OCD. In this study, we investigated neurocognitive functioning in a large and representative sample of newly diagnosed children and adolescents with OCD compared to non-psychiatric controls. Children and adolescents with OCD (n = 119) and non-psychiatric controls (n = 90) underwent psychopathological assessment, intelligence testing, and a neurocognitive test battery spanning cognitive flexibility, planning and decision-making, working memory, fluency, and processing speed. The MANOVA main effect revealed that children and adolescents with OCD performed significantly worse than the control group (p < .001, η p 2 = 0.256). Atypical patient performance was particularly found for indices of cognitive flexibility, decision-making, working memory, and processing speed. We found no evidence of differences in planning or fluency. Moreover, we found no significant associations between neurocognitive performance and OCD symptom severity or comorbidity status. Our results indicate that children and adolescents with OCD show selective atypical neurocognitive functioning. These difficulties do not appear to drive their OCD symptoms. However, they may contribute to lifespan difficulties and interfere with treatment efficacy, an objective of our research currently.

Neurological soft signs as trait markers of a subset of patients with obsessive-compulsive disorder with low insight and altered cognitive abilities

Neurological soft signs (NSS) are subtle motor control impairments that include involuntary movements and abnormalities of motor coordination, sensory integration and lateralization. They engage different brain networks, including the prefrontal networks that support the higher cognitive functions that are dysfunctional in obsessive-compulsive disorder (OCD). This study investigated the relationships between the presence of NSS and patients' severity of OCD symptoms, insight, and treatment resistance in a sample of 63 patients. Treatment-resistance was assessed considering all the treatments the patients received during the course of their disease. The four dimensions of OCD defined in the dimensional obsessive-compulsive scale were considered. Links between the patients' cognitive abilities and NSS were assessed using tests targeting specifically the core components of executive functions. As expected, OCD patients displayed more NSS than individually matched control participants. In OCD patients, high NSS scores were associated with poor insight and lower cognitive abilities. Multiple regression analysis identified worse visuospatial working memory, attentional control, and verbal fluency as predictive factors of high NSS scores among cognitive functions. Unexpectedly, the patients displaying symptoms in the contamination/washing dimension displayed less NSS than the other patients. In contrast, neither the severity of OCD symptoms nor long-range treatment resistance was significantly related to patients' NSS scores. Altogether, our findings suggest that high NSS scores may be a trait marker of a subset of OCD patients with low insight and particularly altered cognitive abilities who would not express the contamination/washing dimension of the pathology.

Investigating Retrospective and Prospective Metamemory Judgments During Episodic Memory in Patients With Obsessive-Compulsive Disorders

It is clear evidence that individuals diagnosed with obsessive-compulsive disorder (OCD) lack confidence in their memory and have low metamemory performance (judgment and accuracy). However, it is still unclear whether low metamemory performance is specific to first, domain general or domain specific, and second, to stimulus domain. To address these issues, we compared individuals diagnosed with OCD and healthy controls (HCs) on recognition, retrospective (judgments of learning [JOL]) and prospective (feeling of knowing [FOK]) metamemory judgments and under three different episodic memory tasks, which consisted of symptom-free, familiar and unfamiliar stimuli (word, scene, and face photo). OCD patients showed lower recognition performance, JOL and FOK judgments, and accuracy in all tasks than HCs. Also, OCD patients were slower than HCs during all cognitive performances. In both groups, metamemory performances were lower in familiar items than unfamiliar items. However, recognition performances were not affected by stimulus type. Our results support the idea of general episodic memory and a metamemory deficit in OCD. Moreover, metamemory deficits in OCD are domain general.

Cognitive Training in Obsessive-Compulsive Disorder: A Systematic Review

Background

Cognitive training (CT) for illness-linked neuropsychological deficits has been attempted in psychiatric disorders and, more recently, in obsessive-compulsive disorder (OCD). However, studies are few and far between, with a limited understanding of factors contributing to efficacy. This article aims to provide a comprehensive critical review of studies employing CT in OCD.

Methods

This systematic review follows the Preferred Reporting of Items for Systematic Review and Meta-Analyses Protocols. Empirical studies that used any form of CT/remediation in individuals with OCD were included.

Results

Eight articles met the criteria for inclusion, of which five were randomized controlled trials, two were case series, and one was an open-label trial. The studies have predominantly demonstrated improved trained cognitive functions, with only two showing generalization to untrained domains like clinical symptoms and socio-occupational functioning.

Conclusion

There are few controlled trials of CT in OCD, which limits conclusions of efficacy. Given the sparse research in the area, the review summarizes the current status of research and examines important methodological considerations that may inform future studies.

Putting things right: An experimental investigation of memory biases related to symmetry, ordering and arranging behaviour

BACKGROUND AND OBJECTIVES

Research indicates the presence of both explicit and implicit memory biases for threat. However, empirical support for the presence of memory biases related to symmetry, ordering and arranging is lacking, despite the fact that many individuals report anxiety associated with their personal belongings being out of place. The aim of this experiment was to examine memory biases for disorderliness and their associations with symmetry, ordering and arranging symptoms.

METHODS

Eighty undergraduate participants were assigned to one of four conditions, consisting of rooms in which objects were arranged according to different levels of disorderliness (orderly, slightly disorderly, slightly orderly, and disorderly). Participants next completed a memory task in which their memory for disordered vs. ordered objects was assessed. Measures of OCD symptoms, preference for symmetry, OCD belief domains, anxiety and depression were completed.

RESULTS

Analyses indicated that participants in the slightly disorderly condition showed significantly better recall and recognition for the disordered items than for the ordered items, and that those in the slightly orderly condition showed the same pattern in recall, but not recognition. No associations were found between a preference for symmetry and memory biases.

LIMITATIONS

The sample scored particularly low on our measure of symptoms of preference for symmetry, compromising the generalizability of our results.

CONCLUSIONS

Findings provide evidence for a general memory bias for disorderliness, although this bias does not appear to be associated with symmetry, ordering and arranging symptoms. Results are discussed from a cognitive-behavioural perspective with the consideration of feelings of incompleteness.

Exploring the relationship between context and obsessions in individuals with obsessive-compulsive disorder symptoms: a narrative review

Obsessions in obsessive-compulsive disorder (OCD) have long been proposed to differ from intrusive thoughts in unaffected individuals based on appraisal of the thoughts. However, more recent research indicates that cognitive processes behind obsessions may differ significantly from those in healthy individuals concerning their contextual relationship. This narrative literature review summarizes current evidence for the role of context-relatedness for obsessions in OCD and intrusive thoughts in affected and unaffected individuals. The review encompasses a total of five studies, two of which include individuals diagnosed with OCD (one study also includes a group of unaffected control individuals), while the other three studies investigate the relationship between OCD symptoms and context in unaffected individuals. As assessed by mainly self-reports, the review examines the connection between thoughts and their context, shedding light on how the repetition and automaticity of thoughts, as well as their detachment from context over time contribute to defining obsessions in contrast to intrusive thoughts. However, the link with context depends on the content of the obsessions. We propose the term "decontextualization of thoughts" to describe the phenomenon that obsessions gradually lose their connection with external context during the development of OCD. Future research should investigate whether this hypothesis can be supported by experimental evidence and identify whether this shift might be more likely a cause or a consequence of the disorder.

Comorbidities and Disease Duration in Tourette Syndrome: Impact on Cognition and Quality of Life of Children

BACKGROUND

Cognitive functions represent foundational factors for mental health and quality of life (QoL). In Tourette syndrome (TS), psychiatric comorbidities are common and have been inconsistently reported to affect the cognition and QoL of patients, while the role of tic disorder duration has not been yet explored.

METHODS

To examine how comorbidities and TS duration may influence cognition and QoL, N = 80 children with TS (6-16 years) were evaluated using the Wechsler Intelligence Scale for Children (WISC-IV). Standardized questionnaires were used to assess the presence and severity of TS main comorbidities and QoL. Data were interpreted using linear correlations, regression, and mediation analysis.

RESULTS

Depression and attention-deficit/hyperactivity disorder (ADHD) symptoms accounted for poorer cognitive performance. Anxiety oppositely predicted better cognitive performance, while no significant role for obsessive compulsive disorder (OCD) was observed. Disease duration was associated with lower total IQ, verbal reasoning, and working memory abilities. Depression, anxiety, and TS duration also deeply influenced QoL measures.

CONCLUSIONS

TS common comorbidities have a differential impact on the cognitive abilities of children and adolescents, which translates into a complex influence on their perceived QoL. A longer clinical history of tics was related to worse cognitive outcomes, which prompts further consideration of disease duration in both clinical and research settings involving children and adolescents.

Impact of sleep disruption on BDD symptoms and treatment response

BACKGROUND

Body dysmorphic disorder (BDD) is severe, undertreated, and relatively common. Although gold-standard cognitive behavioral therapy (CBT) for BDD has strong empirical support, a significant number of patients do not respond. More work is needed to understand BDD's etiology and modifiable barriers to treatment response. Given its high prevalence and impact on the development, maintenance, and treatment of related, frequently comorbid disorders, sleep disruption is a compelling, but not-yet studied factor.

METHODS

Data were drawn from a randomized controlled trial of guided smartphone app-based CBT for BDD. Included participants were offered 12-weeks of treatment, immediately (n = 40) or after a 12-week waitlist (n = 37). Sleep disruption and BDD symptom severity were assessed at baseline, week-6, and week-12.

RESULTS

Hypotheses and analysis plan were pre-registered. Two-thirds of patients reported significant insomnia symptoms at baseline. Baseline severity of sleep disruption and BDD symptoms were not related (r = 0.02). Pre-treatment sleep disruption did not predict BDD symptom reduction across treatment, nor did early sleep improvements predict greater BDD symptom improvement. Early BDD symptom improvement also did not predict later improvements in sleep.

LIMITATIONS

Limitations include the small sample, restricted ranges of BDD symptom severity and treatment response, and few metrics of sleep disruption.

CONCLUSIONS

Although insomnia was disproportionately high in this sample and both BDD symptoms and sleep improved in treatment, results suggest sleep and BDD symptoms may function largely independent of one another. More work is encouraged to replicate and better understand findings as well as potential challenges and benefits of addressing sleep in BDD.

Abnormalities of structural covariance of insular subregions in drug-naïve OCD patients

The insula plays a significant role in the neural mechanisms of obsessive-compulsive disorder. Previous studies have identified functional and structural abnormalities in insula in obsessive-compulsive disorder patients. The predictive coding model in the context of interoception can explain the psychological and neuropathological manifestations observed in obsessive-compulsive disorder. The model is based on the degree of laminar differentiation of cerebral cortex. The interindividual differences in a local measure of brain structure often covary with interindividual differences in other brain regions. We investigated the anatomical network involving the insula in a drug-naïve obsessive-compulsive disorder sample. We recruited 58 obsessive-compulsive disorder patients and 84 matched health controls. The cortical thickness covariance maps between groups were compared at each vertex. We also evaluated the modulation of Yale-Brown Obsessive-Compulsive Scale scores and obsessive-compulsive disorder duration on thickness covariance. Our findings indicated that the thickness covariance seeded from granular and dysgranular insula are different compared with controls. The duration and severity of obsessive-compulsive disorder can modulate the thickness covariance of granular and dysgranular insula with posterior cingulate cortex and rostral anterior cingulate cortex. Our results revealed aberrant insular structural characteristics and cortical thickness covariance in obsessive-compulsive disorder patients, contributing to a better understanding of the involvement of insula in the pathological mechanisms underlying obsessive-compulsive disorder.

"Consumed by creed": Obsessive-compulsive symptoms underpin ideological obsession and support for political violence

Radicalization is a process by which individuals are introduced to an ideological belief system that encourages political, religious, or social change through the use of violence. Here we formulate an obsessive-compulsive disorder (OCD) model of radicalization that links obsessive passion (OP; one of the best predictors of radical intentions) to a larger body of clinical research. The model's central tenet is that individual differences in OCD symptom severity could shape radical intentions via their influence on OP. Across four ideological samples in the United States (Environmental activists, Republicans, Democrats, and Muslims, Ntotal  = 1114), we found direct effects between OCD symptom severity and radical intentions, as well as indirect effects of OCD on radical intentions via OP. Even after controlling for potential individual difference and clinical confounds (e.g., adverse childhood experiences, loss of significance, and substance abuse), these relationships remained robust, implying that OCD plays a significant role in the formation of violent ideological intentions and opening new avenues for the treatment and prevention of violent extremism. We discuss the implications of conceptualizing radicalization as an OCD-like disorder with compulsive violent tendencies and ideology-related concerns.

Mapping the neuroanatomical abnormalities in a phenotype of male compulsive rats

Compulsivity is considered a transdiagnostic dimension in obsessive-compulsive and related disorders, characterized by heterogeneous cognitive and behavioral phenotypes associated with abnormalities in cortico-striatal-thalamic-cortical circuitry. The present study investigated the structural morphology of white and gray matter in rats selected for low- (LD) and high- (HD) compulsive drinking behavior on a schedule-induced polydipsia (SIP) task. Regional brain morphology was assessed using ex-vivo high-resolution magnetic resonance imaging (MRI). Voxel-based morphometry of segmented MRI images revealed larger white matter volumes in anterior commissure and corpus callosum of HD rats compared with LD rats. HD rats also showed significantly larger regional volumes of dorsolateral orbitofrontal cortex, striatum, amygdala, hippocampus, midbrain, sub-thalamic nucleus, and cerebellum. By contrast, the medial prefrontal cortex was significantly smaller in HD rats compared with LD rats with no significant group differences in whole brain, ventricular, or cerebrospinal fluid volumes. These findings show that limbic cortico-basal ganglia structures implicated in impulse control disorders are distinct in rats that are vulnerable to develop compulsive behavior. Such abnormalities may be relevant to the etiology of compulsive disorders in humans.

Increased error rate and delayed response to negative emotional stimuli in antisaccade task in obsessive-compulsive disorder

Ample evidence links impaired inhibitory control, attentional distortions, emotional dysregulation, and obsessive-compulsive disorder (OCD). However, it remains unclear what underlies the deficit that triggers the OCD cycle. The present study used an antisaccade paradigm with emotional valences to compare eye movement patterns reflecting inhibitory control and attention switching in OCD and healthy control groups. Thirty-two patients with OCD and thirty healthy controls performed the antisaccade task with neutral, positive, and negative visual images served as fixation stimuli. Presentation of the fixation stimulus overlapped with target stimuli appearance for 200 ms. The OCD group showed more errors to negative stimuli than the control group and they also performed antisaccades more slowly to negative and neutral stimuli than positive ones. Other patterns, including mean gaze velocity of correct antisaccades did not differ between groups. The mean gaze velocity of correct antisaccades was higher for negative and positive stimuli than for neutral stimuli in both groups. The peak velocity parameter did not show any differences either between groups or between valences. The findings support a hypothesis that an attentional bias toward negative stimuli interferes with inhibitory control in OCD.

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

Background

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.

Aims

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.

Methods

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.

Results

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.

Conclusion

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.

Altered prefrontal beta oscillatory activity during removal of information from working memory in obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) is related to working memory impairment. Since patients with OCD have difficulty controlling their obsessive thoughts, removal of irrelevant information might be important in the pathophysiology of OCD. However, little is known about brain activity during the removal of information from working memory in patients with OCD. Our goal was to explore potential deficits in inhibitory function related to working memory processes in patients with OCD.

METHODS

Sixteen OCD patients and 20 healthy controls (HCs) were recruited. We compared in prefrontal alpha and beta band activity derived from magnetoencephalography (MEG) between patients with OCD and HCs during multiple phases of information processing associated with working memory, especially in post-trial period of the visuospatial working memory task (the delayed matching-to-sample task), which is presumed to be related to the information removal process of working memory.

RESULTS

Prefrontal post-trial beta power change (presumed to occur at high levels during the post-trial period) exhibited significant reductions in patients with OCD compared to HCs. In addition, the post-trial beta power change was negatively correlated with Obsessive-Compulsive Inventory-Revised total scores in patients with OCD.

CONCLUSIONS

These findings suggest that impairment in the removal of information from working memory might be a key mechanism underlying the inability of OCD patients to rid themselves of their obsessions.

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

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

Failures of Urge Suppression in Obsessive-Compulsive Disorder: Behavioral Modeling Using a Blink Suppression Task

Many individuals with obsessive-compulsive disorder (OCD) report sensory-based urges (e.g. 'not-just-right experiences') in addition to, or instead of, concrete fear-based obsessions. These sensations may be comparable to normative "urges-for-action" (UFA), such as the urge to blink. While research has identified altered functioning of brain regions related to UFA in OCD, little is known about behavioral patterns of urge suppression in the disorder. Using an urge-to-blink task as a model for sensory-based urges, this study compared failures of urge suppression between OCD patients and controls by measuring eyeblinks during 60-second blocks of instructed blink suppression. Cox shared frailty models estimated the hazard of first blinks during each 60-second block and recurrent blinks following each initial erroneous blink. OCD patients demonstrated a higher hazard of first and recurrent blinks compared to controls, suggesting greater difficulty resisting repetitive sensory-based urges. Within OCD, relationships between task outcomes and symptom severity were inconsistent. Findings provide support for a deficit in delaying initial urge-induced actions and terminating subsequent actions in OCD, which is not clearly related to clinical heterogeneity. Elucidating the nature of behavioral resistance to urges is relevant for informing conceptualizations of obsessive-compulsive psychopathology and optimizing treatment outcomes.

Balance-energy of resting state network in obsessive-compulsive disorder

Stability of the brain functional network is directly linked to organization of synchronous and anti-synchronous activities. Nevertheless, impact of arrangement of positive and negative links called links topology requires to be well understood. In this study, we investigated how topology of the functional links reduce balance-energy of the brain network in obsessive-compulsive disorder (OCD) and push the network to a more stable state as compared to healthy controls. Therefore, functional associations between the regions were measured using the phase synchrony between the EEG activities. Subsequently, balance-energy of the brain functional network was estimated based on the quality of triadic interactions. Occurrence rates of four different types of triadic interactions including weak and strong balanced, and unbalanced interactions were compared. In addition, impact of the links topology was also investigated by looking at the tendency of positive and negative links to making hubs. Our results showed although the number of positive and negative links were not statistically different between OCD and healthy controls, but positive links in OCDs' brain networks have more tendency to make hub. Moreover, lower number of unbalanced triads and higher number of strongly balanced triad reduced the balance-energy in OCDs' brain networks that conceptually has less requirement to change. We hope these findings could shed a light on better understanding of brain functional network in OCD.

Cognitive outcomes following functional neurosurgery in refractory OCD patients: a systematic review

Neurosurgery is a therapeutic option for patients with refractory obsessive-compulsive disorder who do not respond to previous treatments. Although its efficacy in reducing clinical symptomatology has been proven, few studies have analyzed its effects at the cognitive level. The aim of this systematic review was to describe the cognitive outcomes of functional neurosurgery in patients that went through capsulotomies or cingulotomies. PubMed, Medline, Scopus, PsycInfo, PsyArticles, and Web of Knowledge were searched for studies reporting cognitive outcomes in refractory obsessive-compulsive patients after capsulotomies and cingulotomies. The risk of bias was assessed with the Assessment Tool for Before-After (Pre-Post) Studies With No Control Group tool; 13 studies met inclusion criteria, including 205 refractory obsessive-compulsive disorder patients for both surgical procedures. Results showed a substantial number of studies that did report significant cognitive improvement after surgery, being this improvement specially related to memory and executive functions. The second-most frequent finding is the maintenance of cognitive performance (nor improvement or worsening). From a neuropsychological point of view, this outcome might be considered a success, given that it is accompanied by amelioration of obsessive-compulsive symptoms. Subtle cognitive adverse effects have also been reported. Neurosurgery procedures appear to be safe from a cognitive point of view. Methodological issues must be improved to draw clearer conclusions, but capsulotomies and cingulotomies constitute an effective alternative treatment for refractory obsessive-compulsive disorder patients.

Data-Driven Pupil Response Profiles as Transdiagnostic Readouts for the Detection of Neurocognitive Functioning in Affective and Anxiety Disorders

BACKGROUND

Neurocognitive functioning is a relevant transdiagnostic dimension in psychiatry. As pupil size dynamics track cognitive load during a working memory task, we aimed to explore if this parameter allows identification of psychophysiological subtypes in healthy participants and patients with affective and anxiety disorders.

METHODS

Our sample consisted of 226 participants who completed the n-back task during simultaneous functional magnetic resonance imaging and pupillometry measurements. We used latent class growth modeling to identify clusters based on pupil size in response to cognitive load. In a second step, these clusters were compared on affective and anxiety symptom levels, performance in neurocognitive tests, and functional magnetic resonance imaging activity.

RESULTS

The clustering analysis resulted in two distinct pupil response profiles: one with a stepwise increasing pupil size with increasing cognitive load (reactive group) and one with a constant pupil size across conditions (nonreactive group). A larger increase in pupil size was significantly associated with better performance in neurocognitive tests in executive functioning and sustained attention. Statistical maps of parametric modulation of pupil size during the n-back task showed the frontoparietal network in the positive contrast and the default mode network in the negative contrast. The pupil response profile of the reactive group was associated with more thalamic activity, likely reflecting better arousal upregulation and less deactivation of the limbic system.

CONCLUSIONS

Pupil measurements have the potential to serve as a highly sensitive psychophysiological readout for detection of neurocognitive deficits in the core domain of executive functioning, adding to the development of valid transdiagnostic constructs in psychiatry.

The Effect of Symptom-Provocation on Inhibitory Control in Obsessive-Compulsive Disorder Patients Is Contingent upon Chronotype and Time of Day

Studies have shown that alertness can affect inhibitory control, the mechanism responsible for stopping behaviors, thoughts, or emotions. Inhibitory control is particularly important for helping individuals with Obsessive-Compulsive Disorder (OCD) resisting their symptoms. Chronotype is the mechanism governing an individual's fluctuation of alertness throughout the day. Previous studies have shown that individuals with a 'morning' chronotype have worse OCD symptoms in the evening and vice versa. We administered a novel 'symptom-provocation stop signal task' (SP-SST), in which individually tailored OCD triggers were presented and inhibitory control was measured. Twenty-five treatment-seeking OCD patients completed the SP-SST three times per day for seven consecutive days. Stop signal reaction time (SSRT), which measures inhibitory control, was calculated separately for symptom-provocation trials and for neutral trials. Results yielded that: (a) stopping was significantly harder in the symptom-provocation compared to neutral trials, and (b) the chronotype by time-of-day interaction predicts inhibition for both symptom-provocation and neutral trials, indicating better inhibition in the optimal time of day. Furthermore, we concluded that individually tailored OCD triggers have a detrimental effect on inhibitory control. Most importantly, higher alertness levels, which can be predicted by the interaction of chronotype and time of day, affect inhibitory control, both in general and for OCD triggers specifically.

Obsessive-compulsive disorder: Etiology, neuropathology, and cognitive dysfunction

BACKGROUND

This review provides an overview of obsessive-compulsive disorder (OCD) symptoms, including the four partially distinct subtypes of the disorder, current diagnostic criteria, and common comorbidities. Critically, it focuses on the etiology of OCD, including its underlying neuropathology, and examines cognitive dysfunction in OCD.

METHODS

This review study was conducted by library method.

RESULTS

We show how dysfunction in cortico-striato-thalamo-cortical (CSTC) circuits may underpin symptoms; and shed light on the putative neurochemistry within these loops such as the role of serotonin, dopamine, and glutamate systems. We also show how OCD is characterized by cognitive dysfunction including problems in cognitive flexibility, visuospatial memory, response inhibition, and goal-directed behavior, linked to aberrant activity within CSTC circuits.

CONCLUSIONS

In brief, research questions we shed light on include (1) what are the symptoms in OCD; (2) what is the etiology of the disorder and do existing models explain OCD; and (3) what are key cognitive deficits in OCD and do these improve with treatment?

High treatment resistance is associated with lower performance in the Stroop test in patients with obsessive-compulsive disorder

Around 50% of the patients with obsessive-compulsive disorder (OCD) are resistant to treatment, and patients with OCD show alterations in a broad range of cognitive abilities. The present study investigated the links between treatment-resistance, executive and working memory abilities, and the severity of OCD symptoms among 66 patients with OCD. The patients performed seven tests gauging their executive functions and working memory and filled in questionnaires for OCD severity and insight into their pathology. In addition, the executive and working memory abilities of a subset of these patients were compared with those of individually matched control participants. In contrast with previous studies, patients' treatment resistance was evaluated by considering the clinical outcomes of all the treatments that they received during the course of their disease. Higher treatment resistance was associated with lower performance in one particular executive test, the Stroop test, which assessed patients' ability to inhibit prepotent/automatic responses. Older age and more severe OCD symptoms were also associated with higher treatment resistance. Regardless of OCD severity, the patients displayed small to moderate deficits across most components of executive functions compared to control participants. Interestingly, patients with OCD took more time than control participants to perform speeded neuropsychological tests but never made more errors. Altogether, this study shows that the treatment-resistance of patients with OCD may be reliably quantified over the course of years and treatments using Pallanti and Quercioli's (2006) treatment resistance-related scales. The data suggest that the Stroop test could be used clinically to anticipate treatment outcomes in to-be-treated patients.

The genomics of visuospatial neurocognition in obsessive-compulsive disorder: A preliminary GWAS

BACKGROUND

The study of Obsessive-Compulsive Disorder (OCD) genomics has primarily been tackled by Genome-wide association studies (GWAS), which have encountered troubles in identifying replicable single nucleotide polymorphisms (SNPs). Endophenotypes have emerged as a promising avenue of study in trying to elucidate the genomic bases of complex traits such as OCD.

METHODS

We analyzed the association of SNPs across the whole genome with the construction of visuospatial information and executive performance through four neurocognitive variables assessed by the Rey-Osterrieth Complex Figure Test (ROCFT) in a sample of 133 OCD probands. Analyses were performed at SNP- and gene-level.

RESULTS

No SNP reached genome-wide significance, although there was one SNP almost reaching significant association with copy organization (rs60360940; P = 9.98E-08). Suggestive signals were found for the four variables at both SNP- (P < 1E-05) and gene-levels (P < 1E-04). Most of the suggestive signals pointed to genes and genomic regions previously associated with neurological function and neuropsychological traits.

LIMITATIONS

Our main limitations were the sample size, which was limited to identify associated signals at a genome-wide level, and the composition of the sample, more representative of rather severe OCD cases than a population-based OCD sample with a broad severity spectrum.

CONCLUSIONS

Our results suggest that studying neurocognitive variables in GWAS would be more informative on the genetic basis of OCD than the classical case/control GWAS, facilitating the genetic characterization of OCD and its different clinical profiles, the development of individualized treatment approaches, and the improvement of prognosis and treatment response.

Atypical oscillatory dynamics during emotional face processing in paediatric obsessive-compulsive disorder with MEG

Children and youth with obsessive-compulsive disorder (OCD) demonstrate difficulties with social, emotional and cognitive functions in addition to the core diagnosis of obsessions and compulsions. This is the first magnetoencephalography (MEG) study to examine whole-brain neurophysiological functional connectivity of emotional face processing networks in paediatric OCD. Seventy-two participants (OCD: n = 36; age 8-17 yrs; typically developing controls: n = 36, age 8-17 yrs) completed an implicit emotional face processing task in the MEG. Functional connectivity networks in canonical frequency bands were compared between groups, and within OCD and control groups between emotions (angry vs. happy). Between groups, participants with OCD showed increased functional connectivity in the gamma band to angry faces, suggesting atypical perception of angry faces in OCD. Within groups, the OCD group showed greater engagement of the beta band, suggesting the over-use of top-down processing when perceiving happy versus angry emotions, while controls engaged in bottom-up gamma processing, also greater to happy faces. Over-activation of top-down processing has been linked to difficulties modifying one's cognitive set. Findings establish altered patterns of neurophysiological connectivity in children with OCD, and are striking in their oscillatory specificity. Our results contribute to a greater understanding of the neurobiology of the disorder, and are foundational for the possibility of alternative targets for intervention.

Structural and functional deficits and couplings in severe and moderate OCD

Changes in gray matter volume and functional connections have been frequently observed in patients with obsessive compulsive disorder. However, different grouping may cause diverse volume alterations and could draw more adverse conclusions about the pathophysiology of obsessive compulsive disorder(OCD). Most of them preferred to divide subjects into patients and healthy controls, rather than a detailed subgroup. Moreover, multimodal neuroimaging studies about structural-functional defects and couplings are rather rare. Our aim was to explore gray matter volume(GMV) and functional networks abnormalities induced by structural deficits based on severity of Yale-Brown Obsessive Compulsive Scale(Y-BOCS) symptom including OCD patients with severe(S-OCD, n = 31) and moderate symptoms(M-OCD, n = 42) and healthy controls (HCs, n = 54); Voxel-based morphometry(VBM) method was used to detect GMV differences among three groups, then used as masks according to one-way analysis of variance(ANOVA) results for the subsequent resting-state functional connectivity(rs-FC) analysis. Besides, correlation and subgroup analysis were performed to detect the potential roles of structural deficits between every two groups. ANOVA analysis showed that both S-OCD and M-OCD had increased volume in anterior cingulate cortex(ACC), left precuneus(L-Pre) and paracentral lobule(PCL), postcentral gyrus, left inferior occipital gyrus(L-IOG) and right superior occipital gyrus(R-SOG) and bilateral cuneus, middle occipital gyrus(MOG), and calcarine. Additionally, increased connections between Pre and angular gyrus(AG) and inferior parietal lobule(IPL) have been found. Moreover, connections between the left cuneus and lingual gyrus, between IOG and left lingual gyrus, fusiform and between L-MOG and cerebellum were also included. Subgroup analysis showed that decreased GMV in left caudate was negatively correlated with compulsion and total score in patients with moderate symptom compared to HCs. Our findings indicated that altered GMV in occipital-related regions, Pre, ACC and PCL and the disrupted FC networks including MOG-cerebellum and Pre-AG and IPL. Moreover, subgroup GMV analysis furtherly revealed negative associations between GMV changes and Y-BOCS symptom, offering preparatory proof for the involvement of structural and functional deficits in cortical-subcortical circuitry. Thus, they could provide insights into the neurobiological basis.

Attention allocation in OCD: A systematic review and meta-analysis of eye-tracking-based research

INTRODUCTION

Cognitive models of obsessive-compulsive disorder (OCD) implicate heightened attention allocation to stimuli related to one's obsessions in the disorder. Recently, to overcome several limitations of reaction time-based measures, eye-tracking methodology has been increasingly used in attentional research.

METHODS

A meta-analysis of studies examining attention allocation towards OCD-related vs. neutral stimuli, using eye-tracking methodology and a group-comparison design, was conducted conforming to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Separate meta-analyses were performed for attentional vigilance (both latency and location of first fixations) and maintenance (total dwell time and total fixation count, conjointly). Each meta-analysis was conducted twice - once including all studies (main analysis) and once only including studies using the free-viewing paradigm (secondary analysis).

RESULTS

The systematic search yielded a total of nine studies. Of those, eight provided the needed data to be included in the meta-analysis. No evidence emerged for vigilance via latency to first fixation. Vigilance reflected via first fixation location emerged in the main analysis, but not in the secondary one. Evidence for attentional maintenance was found only when analyzing free-viewing studies exclusively (the secondary analysis).

LIMITATIONS

To increase the accuracy of the research question, correlational studies were excluded, resulting in a small number of available studies.

CONCLUSIONS

OCD may be characterized by vigilance, but mainly in tasks entailing specific demands and/or goals. Conversely, attentional maintenance may be evident only when using tasks that pose no requirements or demands for participants.

Formal vs. intuitive categorization and obsessive-compulsive symptoms

BACKGROUND AND OBJECTIVES

Obsessive-compulsive disorder (OCD) is often characterized by rigidity regarding rules and perfectionism, which suggests a formal reasoning style. However, other characterizations suggest an overreliance on internal cues for behavior termination, which suggests a more intuitive reasoning style. We examine reasoning styles in OCD by assessing categorization preferences traditionally classified to rule-based and family resemblance categorization.

METHOD

An initial study (n = 41) and an online replication (n = 85) were conducted. In both studies, groups scoring high and low on OCD symptoms were compared. Categorization preferences and confidence ratings were examined via a modification of a classic categorization task. The task was administered in three conditions: under time limits, with no time limits, and with explicit explanation of both categorization styles.

RESULTS

Aggregating results from both studies showed that obsessive-compulsive symptoms were associated with a reduced preference for rule-based categorization reflecting a tendency towards a more intuitive, non-formal reasoning style. This preference was apparent even when rules were explicitly described. Group differences regarding confidence were inconclusive.

LIMITATIONS

Generalizing results to the clinical population requires further research, and specificity to OC symptoms should be determined.

CONCLUSIONS

Challenging the expected association between OCD and rigidity and perfectionism, findings support suggestions that OCD reasoning strays from formal reasoning. This may explain some of the subjective and idiosyncratic rules adopted by individuals with OCD.

Cognitive Neuroscience of Obsessive-Compulsive Disorder

Cognitive neuroscientific research has the ability to yield important insights into the complex neurobiological processes underlying obsessive-compulsive disorder (OCD). This article provides an updated review of neuroimaging studies in seven neurocognitive domains. Findings from the literature are discussed in the context of obsessive-compulsive phenomenology and treatment. Expanding our knowledge of the neural mechanisms involved in OCD could help optimize treatment outcomes and guide the development of novel interventions.

Executive functioning in body dysmorphic disorder and obsessive-compulsive disorder

OBJECTIVE

To assess executive functions (EFs) in patients with body dysmorphic disorder (BDD) and obsessive-compulsive disorder (OCD) compared with healthy controls.

METHODS

Adults diagnosed with BDD (n = 26) or OCD (n = 29) according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and healthy controls (n = 28) underwent validated and computerized neuropsychological tests, spatial working memory (SWM), intra-extra-dimensional set shifting (IED), and stop signal task (SST), from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Test performance was compared between groups, and correlated with standardized symptom severity of BDD and OCD. Significance level was set to P < .05.

RESULTS

There were no statistically significant between-group differences on key outcome measures in SWM, IED, or SST. There was a weak positive correlation between symptom severity and test errors on SWM and IED in both OCD and BDD groups; increased clinical severity was associated with more errors in these tests. Furthermore, there was a negative correlation between symptom severity and SST in the BDD group.

CONCLUSIONS

Patients with BDD or OCD did not differ from healthy control subjects in terms of test performance; however, there were several statistically significant correlations between symptom severity and performance in those with BDD or OCD. More studies on EFs in BDD and OCD are required to elucidate if there are differences in EFs between these two disorders.

Heightened but Inefficient Thought-Action Fusion in Obsessive-Compulsive Disorder: New Insight From a Multiple Trial Version of the Classic Thought-Action Fusion Experiment

OBJECTIVE

Thought-action fusion (TAF), which is a tendency to make the relationship between one's thoughts and external consequences, is a dysfunctional belief linked to obsessive-compulsive disorder (OCD). While the TAF is commonly evaluated using the Thought-Action Fusion Scale (TAFS), it cannot fully reflect the actual experience of experimentally evoked TAF. In the present study, we applied a multiple-trial version of the classic TAF experiment and evaluate two variables, reaction time (RT) and emotional intensity (EI).

METHODS

Ninety-three patients with OCD and 45 healthy controls (HCs) were recruited. The participants were asked to read the name of a close or neutral person embedded in different positive (PS) or negative (NS) TAF statements. During the experiments, RT and EI were gathered.

RESULTS

The OCD patients presented with longer RT and lower EI in the NS condition than HCs. In each group, the HCs showed a significant relationship between RT in the NS condition and TAFS scores, whereas the patients did not, although they had higher TAFS scores than the HCs. In contrast, the patients showed a trend toward a correlation between RT in the NS condition and guilt.

CONCLUSION

These findings may indicate our multiple-trial version of the classical TAF showed reliable results of the two new variables, especially RT, in the task and allow to newly identify paradoxical patterns in which the TAFS scores are high but actual performance is impaired, that is, the inefficient activation of TAF in OCD.

A diffusion tensor imaging study in schizophrenia patients with clozapine induced obsessive compulsive symptoms

OBJECTIVE

The aim of this study was to evaluate brain connectivity by diffusion tensor imaging (DTI) in schizophrenia patients with clozapine-induced obsessive compulsive symptoms (OCS).

METHODS

Eighteen schizophrenia patients, nine of which had clozapine-induced OCS (Clz-OCS (+)), 9 without OCS (Clz-OCS (-)) and 9 healthy controls were included. Psychopathology was evaluated with Positive and Negative Syndrome Scale and Yale-Brown Obsession and Compulsion Scale in the patient groups. All groups were assesed with neurocognitive tests and DTI.

RESULTS

Tract-Based Spatial Statistics based comparison of DTI revealed lower fractional anisotropy in the genu of corpus callosum (CC), right cingulum, left frontal white matter (WM) in the Clz-OCS (+) group, compared to controls. Fractional anisotropy was found to be lower in the bilateral occipital WM and higher in the bilateral medial temporal regions, anterior limb of internal capsule, cingulum, frontoparietal peripheral WM, right external capsule and genu of CC in Clz-OCS (+) patients compared to Clz-OCS (-).

CONCLUSIONS

WM integrity in several pathways such as cortico-striato-thalamo-cortical circuitry and orbito-frontal tracts seems to be affected differently in patients with Clz-OCS (+). Different neuroplastic effects of clozapine leading to occurrence of OCS in a subgroup of patients is possible, and needs further evaluation by longitudinal follow-up studies.

Dysfunctional Beliefs and Cognitive Performance across Symptom Dimensions in Childhood and Adolescent OCD

Although etiological and maintenance cognitive factors have proved effective in predicting the disease course in youths with OCD, their contribution to symptom severity and specific OCD dimensions has been scarcely examined. In a cohort of children and adolescents with OCD (N = 41; mean age = 14; age range = 10-18 yrs.), we investigated whether certain dysfunctional beliefs and cognitive traits could predict symptom severity, and whether they were differentially associated with specific symptom dimensions. We found that self-oriented and socially prescribed perfectionism and intolerance to uncertainty were associated with higher obsession severity, which was not uniquely related to any neuropsychological variable. Greater severity of obsessions and compulsions about harm due to aggression/injury/violence/natural disasters was predicted by excessive concerns with the expectations of other people. Severity in this dimension was additionally predicted by decreasing accuracy in performing a problem-solving, non-verbal reasoning task, which was also a significant predictor of severity of obsessions about symmetry and compulsions to count or order/arrange. Apart from corroborating both the belief-based and neuropsychological models of OCD, our findings substantiate for the first time the specificity of certain dysfunctional beliefs and cognitive traits in two definite symptom dimensions in youth. This bears important clinical implications for developing treatment strategies to deal with unique dysfunctional core beliefs, and possibly for preventing illness chronicity.

An Integrative Model for Understanding Obsessive-Compulsive Disorder: Merging Cognitive Behavioral Theory with Insights from Clinical Neuroscience

Several models have been proposed for the emergence and maintenance of obsessive-compulsive disorder (OCD). Although these models have provided important insights and inspired treatment development, no single model has yet sufficiently accounted for the complexed phenotype of the disorder. In the current paper, we propose a novel model that integrates elements from cognitive behavioral models of OCD with neurocognitive approaches to the disorder. This Reciprocal Interaction Model (RIM) for OCD is based on two assumptions: (a) similar observed symptoms can stem from different etiological processes; and (b) neuropsychological deficits (such as reduced response inhibition and overreliance on the habit formation system) and cognitive behavioral processes (such as temporary reduction in anxiety after engaging in compulsive behaviors) mutually affect each other such that abnormalities in one system influence the second system and vice-versa-creating a vicious cycle of pathological processes. Indeed, the bidirectional inhibitory connection between anxiety/obsessions and executive control is at the heart of the model. We begin by briefly reviewing the current models for OCD. We then move on to describe the RIM, the supporting evidence for the model, the model's predictions, and potential clinical implications.

Efficacy and fMRI-based response predictors to mindfulness-based cognitive therapy in obsessive-compulsive disorder: Study protocol for a randomised clinical trial

BACKGROUND

Around 40-50% of patients with obsessive-compulsive disorder (OCD) suffer from obsessions and compulsions after receiving first-line treatments. Mindfulness-based cognitive therapy (MBCT) has been proposed as a reasonable augmentation strategy for OCD. MBCT trains to decentre from distressful thoughts and emotions by focusing on them voluntarily and with consciousness. This practice develops alternative ways to deal with obsessions, which could increase non-reactivity behaviours and, in turn, reduce compulsions. This study aims to investigate the efficacy of MBCT to improve OCD symptoms. Secondly, it pursues to investigate which socio-demographic, clinical, and neurobiological characteristics mediate or moderate the MBCT response; and identify potential biomarkers of positive/negative response.

METHODS

This study is a randomised clinical trial (RCT) of 60 OCD patients who do not respond to first-line treatments. Participants will be randomised to either an MBCT program or treatment as usual. The MBCT group will undergo 10 weekly sessions of 120min. Principal outcome: change in OCD severity symptoms using clinician and self-reported measures. Also, participants will undergo a comprehensive evaluation assessing comorbid clinical variables, neuropsychological functioning and thought content. Finally, a comprehensive neuroimaging protocol using structural and functional magnetic resonance imaging will be acquired in a 3T scanner. All data will be obtained at baseline and post-intervention.

DISCUSSION

This study will assess the efficacy of mindfulness in OCD patients who do not achieve clinical recovery after usual treatment. It is the first RCT in this subject examining clinical, neuropsychological and neuroimaging variables to examine the neural patterns associated with the MBCT response.

CLINICAL TRIALS REGISTRATION

NCT03128749.

Neuropsychological performance and predictors of pharmacological treatment response in obsessive compulsive disorder

BACKGROUND

Obsessive Compulsive Disorder (OCD) is characterized by the presence of executive dysfunctions. As organizational strategies may play an important role as a possible endophenotype of the disorder, we decided to investigate non-verbal memory and organizational abilities in OCD. We also investigated how organization and non-verbal memory differ between responder and non-responder patients to pharmacological treatment, to test whether cognitive functions can predict the response to pharmacological treatment.

METHODS

In Study 1, executive and clinical functioning measures were applied to 162 OCD and 95 controls. In Study 2, clinical, intelligence and executive functioning measures were applied to 72 OCD responders and 63 OCD non-responder patients.

RESULTS

OCD patients and controls from Study 1 differed in copy organization (p < 0.01) and delayed recall (p = 0.048). In Study 2, the OCD responders displayed better copy organization (p = 0.013) and lower depressive, anxious and OCD symptoms (p < 0.01 in the three cases). Scores in the following instruments were found to predict the response to pharmacological treatment: HDRS, Y-BOCS, Raven progressive matrices, and Direct digit subtest from the Wechsler's scale (p < 0.01 in all four cases).

LIMITATIONS

In Study 1, the imbalance of the sample can be considered a limitation, whilst in Study 2, some of the levels of pharmacological resistance were not represented.

CONCLUSIONS

In this study, non-verbal memory and organization was affected in OCD. Responder patients also displayed better executive functioning and fluid intelligence. Organizational ability is a predictor of pharmacological response to SSRI monotherapy in a predictive model controlling for anxious symptoms.

Obsessive-compulsive disorder is characterized by decreased Pavlovian influence on instrumental behavior

Obsessive-compulsive disorder (OCD) is characterized by uncontrollable repetitive actions thought to rely on abnormalities within fundamental instrumental learning systems. We investigated cognitive and computational mechanisms underlying Pavlovian biases on instrumental behavior in both clinical OCD patients and healthy controls using a Pavlovian-Instrumental Transfer (PIT) task. PIT is typically evidenced by increased responding in the presence of a positive (previously rewarded) Pavlovian cue, and reduced responding in the presence of a negative cue. Thirty OCD patients and thirty-one healthy controls completed the Pavlovian Instrumental Transfer test, which included instrumental training, Pavlovian training for positive, negative and neutral cues, and a PIT phase in which participants performed the instrumental task in the presence of the Pavlovian cues. Modified Rescorla-Wagner models were fitted to trial-by-trial data of participants to estimate underlying computational mechanism and quantify individual differences during training and transfer stages. Bayesian hierarchical methods were used to estimate free parameters and compare the models. Behavioral and computational results indicated a weaker Pavlovian influence on instrumental behavior in OCD patients than in HC, especially for negative Pavlovian cues. Our results contrast with the increased PIT effects reported for another set of disorders characterized by compulsivity, substance use disorders, in which PIT is enhanced. A possible reason for the reduced PIT in OCD may be impairment in using the contextual information provided by the cues to appropriately adjust behavior, especially when inhibiting responding when a negative cue is present. This study provides deeper insight into our understanding of deficits in OCD from the perspective of Pavlovian influences on instrumental behavior and may have implications for OCD treatment modalities focused on reducing compulsive behaviors.

Are people with obsessive-compulsive disorder under-confident in their memory and perception? A review and meta-analysis

People with obsessive-compulsive disorder (OCD) tend to distrust their memory, perception, and other cognitive functions, and many OCD symptoms can be traced to diminished confidence in one's cognitive processes. For example, poor confidence in recall accuracy can cause doubt about one's memory and motivate repeated checking. At the same time, people with OCD also display performance deficits in a variety of cognitive tasks, so their reduced confidence must be evaluated in relation to their actual performance. To that end, we conducted an exhaustive review and meta-analysis of studies in which OCD participants and non-clinical control participants performed cognitive tasks and reported their confidence in their performance. Our search resulted in 19 studies that met criteria for inclusion in the quantitative analysis, with all studies addressing either memory or perception. We found that both performance and reported confidence were lower in OCD than in control participants. Importantly, however, confidence was more impaired than performance in participants with OCD. These findings suggest that people with OCD are less confident in their memory and perception than they should be, indicating a genuine under-confidence in this population. We discuss potential mechanisms that might account for this finding and suggest avenues for further research into under-confidence and related meta-cognitive characteristics of OCD.

The global assessment of OCD

Obsessive Compulsive Disorder (OCD) is a common mental disorder that often causes great sufferance, with substantial impairment in social functioning and quality of life and affects family and significant relationships. Notwithstanding its severity, OCD is often not adequately diagnosed, or it is diagnosed with delay, leading often to a long latency between onset of the OCD symptoms and the start of adequate treatments. Several factors contribute to the complexity of OCD's clinical picture: early age of onset, chronic course, heterogeneity of symptoms, high rate of comorbidity with other psychiatric disorders, slow or partial response to therapy. Therefore, it is of primary importance for clinicians involved in diagnosing OCD, to assess all aspects of the disorder. This narrative review focuses on the global assessment of OCD, highlighting crucial areas to explore, pointing out the clinical features which are relevant for the treatment of the disorder, and giving an overview of the psychometric tools that can be useful during the screening procedure.

Deep brain stimulation in the ALIC-BNST region targeting the bed nucleus of stria terminalis in patients with obsessive-compulsive disorder: effects on cognition after 12 months

PURPOSE

The aim of this study was to evaluate cognitive effects 12 months after Deep Brain Stimulation (DBS) of the Bed Nucleus of Stria Terminalis (BNST) in patients with refractory Obsessive-Compulsive Disorder (OCD).

METHODS

Eight patients (5 female; mean ± SD age 36 ± 15) with OCD were included. A neuropsychological test battery covering verbal and spatial episodic memory, executive function, and attention was administered preoperatively and 12 months after surgery. Medical records were used as a source for descriptive data to probe for any changes not covered by standardized checklists and the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), the primary outcome measure.

RESULTS

At 12 months, seven patients showed response to DBS: three were full responders (i.e., Y-BOCS ≥ 35% improvement), and four were partial responders (Y-BOCS 25-34% improvement). Relative to baseline, there was a slight decline on visuo-spatial learning (p = 0.027), and improved performance on the Color-Word Interference inhibition/switching subtest (p = 0.041), suggesting improvement in cognitive flexibility.

CONCLUSIONS

DBS in the BNST for treatment refractory OCD generates very few adverse cognitive effects and improves cognitive flexibility after 12 months of stimulation. The improvement in Y-BOCS and the absence of major cognitive side effects support the BNST as a potential target for DBS in severe OCD.

Are failures to suppress obsessive-intrusive thoughts associated with working memory?

BACKGROUND AND OBJECTIVES

Obsessive compulsive disorder (OCD) is characterised by repeated attempts to suppress obsessive-intrusive thoughts (OITs). Nonclinical individuals also regularly engage in thought suppression. Attempts to suppress OITs are often unsuccessful and there is wide variation in suppression abilities across nonclinical and clinical samples. Understanding the mechanisms that explain variations in suppression abilities could enhance our understanding of OCD. This study aimed to investigate one potential mechanism - working memory - using a comprehensive thought suppression task.

METHODS

Eighty-three nonclinical participants completed a computerized thought dismissibility task (in which they replaced an obsessive-intrusive thought with a neutral thought), and a computerized working memory task. Participants also completed measures of OCD and negative mood.

RESULTS

None of the suppression variables (OIT frequency, mean OIT duration, mean latency to return, total OIT duration) were correlated with working memory capacity. Obsessive-compulsive symptoms were correlated with total OIT duration, but the relationship was not significant after controlling for negative mood.

LIMITATIONS

The thought dismissibility task does not account for differences in motivation to suppress OITs. The sample was non-clinical and mostly female.

CONCLUSION

An individual's ability to suppress OITs is not associated with their working memory capacity, suggesting poor working memory does not explain persistent OITs in individuals with OCD.

Impact of Attention-Deficit/Hyperactivity Disorder Comorbidity on Phenomenology and Treatment Outcomes of Pediatric Obsessive-Compulsive Disorder

Objective: This study, with a case-control design, investigates the impact of attention-deficit/hyperactivity disorder (ADHD) comorbidity on the phenomenology and treatment outcomes in a clinical sample of pediatric obsessive-compulsive disorder (OCD). Methods: The data were derived from an evaluation of the sociodemographic and clinical characteristics of 364 children with OCD who were regularly followed up over a 4-year period. Between-group analyses of psychiatric scales were used to compare patients with ADHD comorbidity (n = 144, 39.5%) with their ADHD-free opponents. The clinical course and treatment outcomes of each patient were evaluated based on 4-year clinical follow-up data. Results: Substantial clinical variations in pediatric OCD caused by ADHD comorbidity were identified, including a male preponderance, higher rates of concurrent conduct problems, tic disorders, and learning disabilities, as well as prolonged symptom and treatment durations accompanied by poor response to first-line treatments and higher rates of treatment resistance. Contrary to previous findings, ADHD comorbidity had no impact on the age of OCD onset, and the severity of OCD symptoms was lower in ADHD. With ADHD comorbidity, the OCD symptom course tended to be chronically stable, which may have resulted in complaints persisting into adulthood. In ADHD-free patients, contamination, doubt, religious, somatic obsessions, and cleaning were all more common than in those with ADHD. There was a positive correlation between compulsion scores and the severity of ADHD symptoms, which may be related to increased compulsive coping in ADHD. Impulsivity or compulsivity dominance in the symptom presentation of OCD-ADHD comorbidity may determine phenomenological distinctions such as whether concurrent traits are more prone to tics, conduct problems, or internalizing problems. The primordial associations for clinical characteristics, which were independently associated with ADHD comorbidity, were adjusted using multivariate logistic regression analysis. Clinical variables such as being male, absence of cleaning compulsion, the existence of concurrent conduct problems, tic disorders, and dyslexia, as well as longer treatment duration and poorer treatment response, were all independent predictors of ADHD comorbidity. With an 80.8% accurate classification and relatively fine goodness-of-fit model, the regression model consisting of those predictors had good predictiveness for ADHD comorbidity (R² = 0.543). Conclusions: The close association between pediatric OCD, ADHD, and tic disorders can be defined as a specific subtype of pediatric OCD, characterized by more conduct problems, a chronically stable course of OCD symptoms, and poorer treatment outcomes. Correlational analyses in a longitudinal design and the inclusion of an impulsivity scale would be beneficial for further research to interpret the impulsivity-related correlates in the findings on tic and conduct problems.

Abnormal spontaneous neural activity in hippocampal-cortical system of patients with obsessive-compulsive disorder and its potential for diagnosis and prediction of early treatment response

Early brain functional changes induced by pharmacotherapy in patients with obsessive-compulsive disorder (OCD) in relation to drugs per se or because of the impact of such drugs on the improvement of OCD remain unclear. Moreover, no neuroimaging biomarkers are available for diagnosis of OCD and prediction of early treatment response. We performed a longitudinal study involving 34 patients with OCD and 36 healthy controls (HCs). Patients with OCD received 5-week treatment with paroxetine (40 mg/d). Resting-state functional magnetic resonance imaging (fMRI), regional homogeneity (ReHo), support vector machine (SVM), and support vector regression (SVR) were applied to acquire and analyze the imaging data. Compared with HCs, patients with OCD had higher ReHo values in the right superior temporal gyrus and bilateral hippocampus/parahippocampus/fusiform gyrus/cerebellum at baseline. ReHo values in the left hippocampus and parahippocampus decreased significantly after treatment. The reduction rate (RR) of ReHo values was positively correlated with the RRs of the scores of Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and obsession. Abnormal ReHo values at baseline could serve as potential neuroimaging biomarkers for OCD diagnosis and prediction of early therapeutic response. This study highlighted the important role of the hippocampal-cortical system in the neuropsychological mechanism underlying OCD, pharmacological mechanism underlying OCD treatment, and the possibility of building models for diagnosis and prediction of early treatment response based on spontaneous activity in the hippocampal-cortical system.

Relating psychiatric symptoms and self-regulation during the COVID-19 crisis

Disruptions of self-regulation are a hallmark of numerous psychiatric disorders. Here, we examine the relationship between transdiagnostic dimensions of psychopathology and changes in self-regulation in the early phase of the COVID-19 pandemic. We used a data-driven approach on a large number of cognitive tasks and self-reported surveys in training datasets. Then, we derived measures of self-regulation and psychiatric functioning in an independent population sample (N = 102) tested both before and after the onset of the COVID-19 pandemic, when the restrictions in place represented a threat to mental health and forced people to flexibly adjust to modifications of daily routines. We found independent relationships between transdiagnostic dimensions of psychopathology and longitudinal alterations in specific domains of self-regulation defined using a diffusion decision model. Compared to the period preceding the onset of the pandemic, a symptom dimension related to anxiety and depression was characterized by a more cautious behavior, indexed by the need to accumulate more evidence before making a decision. Instead, social withdrawal related to faster non-decision processes. Self-reported measures of self-regulation predicted variance in psychiatric symptoms both concurrently and prospectively, revealing the psychological dimensions relevant for separate transdiagnostic dimensions of psychiatry, but tasks did not. Taken together, our results are suggestive of potential cognitive vulnerabilities in the domain of self-regulation in people with underlying psychiatric difficulties in face of real-life stressors. More generally, they also suggest that the study of cognition needs to take into account the dynamic nature of real-world events as well as within-subject variability over time.

Objective Cognitive Outcomes and Subjective Emotional Sequelae in Litigating Adults with a Traumatic Brain Injury: The Impact of Performance and Symptom Validity Measures

OBJECTIVE

This study examined the relative contribution of performance and symptom validity in litigating adults with traumatic brain injury (TBI), as a function of TBI severity, and examined the relationship between self-reported emotional symptoms and cognitive tests scores while controlling for validity test performance.

METHOD

Participants underwent neuropsychological assessment between January 2012 and June 2021 in the context of compensation-seeking claims related to a TBI. All participants completed a cognitive test battery, the Personality Assessment Inventory (including symptom validity tests; SVTs), and multiple performance validity tests (PVTs). Data analyses included independent t-tests, one-way ANOVAs, correlation analyses, and hierarchical multiple regression.

RESULTS

A total of 370 participants were included. Atypical PVT and SVT performance were associated with poorer cognitive test performance and higher emotional symptom report, irrespective of TBI severity. PVTs and SVTs had an additive effect on cognitive test performance for uncomplicated mTBI, but less so for more severe TBI. The relationship between emotional symptoms and cognitive test performance diminished substantially when validity test performance was controlled, and validity test performance had a substantially larger impact than emotional symptoms on cognitive test performance.

CONCLUSION

Validity test performance has a significant impact on the neuropsychological profiles of people with TBI, irrespective of TBI severity, and plays a significant role in the relationship between emotional symptoms and cognitive test performance. Adequate validity testing should be incorporated into every neuropsychological assessment, and associations between emotional symptoms and cognitive outcomes that do not consider validity testing should be interpreted with extreme caution.