Cognitive flexibility and response inhibition in patients with Obsessive-Compulsive Disorder and Generalized Anxiety Disorder

The inflexible mind: A critical factor in understanding and addressing COVID-19 vaccine hesitancy

BACKGROUND

Vaccine hesitancy has gained heightened relevance amid the COVID-19 pandemic, underscoring the urgency of understanding its determinants. This study explores the association between Covid-19 vaccine hesitancy, mental health variables and inflexible thinking.

METHODS

A convenience sample of 252 UK adults was assessed online between June 2021-July 2022 (when Covid-19 lockdown restrictions had finally eased). We assessed participants using the Oxford Covid Vaccine Hesitancy Scale (OCVHS), various aspects of mental health, using: the Obsessive-Compulsive Inventory-Revised (OCI-R), Compulsive Personality Assessment Scale (CPAS), Depression, Anxiety, and Stress scale (DASS-21), and finally, performance on a computerized version of the Wisconsin Card Sort Task (WCST). This study was preregistered at the Open Science Framework (https://osf.io/xd5wz).

RESULTS

Multiple regression analyses showed that only cognitive inflexibility, and specifically the WCST item of perseverative errors, significantly predicted vaccine hesitancy.

CONCLUSION

Our exploratory analysis provides the first evidence that cognitive inflexibility, measured using an objective task, is an independent risk-factor for vaccine hesitancy. Public health strategies should consider the impact of an inflexible thinking style on the decision-making of those most at risk of vaccine hesitancy and adapt interventions accordingly.

Neuropsychological Functioning Among Patients with OCD in Asian Countries: A Systematic Review

Objective

This systematic review aimed to identify the effect of obsessive compulsive disorder (OCD) on cognitive processes, such as memory, executive functioning, and cognitive flexibility, among the adult populations of Asian countries.

Methods

The systematic review progressed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. It is comprised of articles sourced from Asian countries published from 2018 to 2022, and literature about deficits in memory, executive functioning, and cognitive flexibility in the OCD population was gathered from five electronic databases, including Google Scholar, PubMed, Research Gate, Science Direct, and Wiley Online Library. Full-text impact factor articles in the English language were considered in this study.

Results

This study screened 44 articles; five were included based on the eligibility criteria for the present systematic review. Four articles found cognitive deficits in the domains of executive functioning, memory, and cognitive flexibility among patients with OCD, whereas results of one article showed normal cognitive performance of the patients. Demographic variables showed no significant differences between patients with OCD and healthy controls.

Conclusion

This systematic review indicated deficits specifically in the cognitive functioning and flexibility of patients with OCD. Despite a noticeable prevalence of OCD in Asian countries, the literature on correlates and neurological functioning is scarce. Further studies are required to examine the effects on the larger population and provide knowledge in those countries and areas where people are suffering because of minimal knowledge regarding OCD.

The capacity of cognitive tests to detect generalized anxiety disorder (GAD): A pilot study

Cognitive impairment remains understudied in generalized anxiety disorder (GAD), despite the high prevalence and substantial burden associated with this disorder. We aimed to assess cognitive impairment in patients with GAD and evaluate the ability of cognitive tests to detect this disorder. Because of its high rate of comorbidity, we also examined how other anxiety disorders and current major depressive episodes affected our results. We tested 263 consecutive general practice outpatients. We used the GAD-7 and the Mini International Neuropsychiatric Interview (MINI) to detect anxiety and mood disorders. We assessed cognitive performance with the Stroop test, a facial emotion recognition test, and the trail-making test (TMT). Compared to patients without GAD, patients with GAD were significantly slower to complete the TMT(B-A) and faster to recognize emotions, especially negative ones such as disgust and anger. When controlling for other anxiety disorders and current major depressive episode, GAD retained a significant effect on the TMT(B-A), but not on the emotion recognition test. The TMT(B-A) could detect GAD with good accuracy (area under the curve (AUC) = 0.83, maximal Youden's index = 0.56), which was by no means comparable to the GAD-7 (AUC = 0.97, Youden's index = 0.81). While it is not efficient enough to replace the GAD-7 as a diagnostic tool, the capacity of the TMT(B-A) to detect GAD emphasizes the importance of cognitive flexibility impairment in GAD.

The brain entropy dynamics in resting state

As a novel measure for irregularity and complexity of the spontaneous fluctuations of brain activities, brain entropy (BEN) has attracted much attention in resting-state functional magnetic resonance imaging (rs-fMRI) studies during the last decade. Previous studies have shown its associations with cognitive and mental functions. While most previous research assumes BEN is approximately stationary during scan sessions, the brain, even at its resting state, is a highly dynamic system. Such dynamics could be characterized by a series of reoccurring whole-brain patterns related to cognitive and mental processes. The present study aims to explore the time-varying feature of BEN and its potential links with general cognitive ability. We adopted a sliding window approach to derive the dynamical brain entropy (dBEN) of the whole-brain functional networks from the HCP (Human Connectome Project) rs-fMRI dataset that includes 812 young healthy adults. The dBEN was further clustered into 4 reoccurring BEN states by the k-means clustering method. The fraction window (FW) and mean dwell time (MDT) of one BEN state, characterized by the extremely low overall BEN, were found to be negatively correlated with general cognitive abilities (i.e., cognitive flexibility, inhibitory control, and processing speed). Another BEN state, characterized by intermediate overall BEN and low within-state BEN located in DMN, ECN, and part of SAN, its FW, and MDT were positively correlated with the above cognitive abilities. The results of our study advance our understanding of the underlying mechanism of BEN dynamics and provide a potential framework for future investigations in clinical populations.

Impaired cognitive flexibility across psychiatric disorders

OBJECTIVE

Problems with cognitive flexibility have been associated with multiple psychiatric disorders, but there has been little understanding of how cognitive flexibility compares across these disorders. This study examined problems of cognitive flexibility in young adults across a range of psychiatric disorders using a validated computerized trans-diagnostic flexibility paradigm. We hypothesized that obsessive-compulsive spectrum disorders (eg, obsessive-compulsive disorder, trichotillomania, and skin-picking disorder) would be associated with pronounced flexibility problems as they are most often associated with irrational or purposeless repetitive behaviors.

METHODS

A total of 576 nontreatment seeking participants (aged 18-29 years) were enrolled from general community settings, provided demographic information, and underwent structured clinical assessments. Each participant undertook the intra-extra-dimensional task, a validated computerized test measuring set-shifting ability. The specific measures of interest were total errors on the task and performance on the extra-dimensional (ED) shift, which reflects the ability to inhibit and shift attention away from one stimulus dimension to another.

RESULTS

Participants with depression and PTSD had elevated total errors on the task with moderate effect sizes; and those with the following had deficits of small effect size: generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), antisocial personality disorder, and binge-eating disorder. For ED errors, participants with PTSD, GAD, and binge-eating disorder exhibited deficits with medium effect sizes; those with the following had small effect size deficits: depression, social anxiety disorder, OCD, substance dependence, antisocial personality disorder, and gambling disorder.

CONCLUSIONS

These data indicate cognitive flexibility deficits occur across a range of mental disorders. Future work should explore whether these deficits can be ameliorated with novel treatment interventions.

Functional connectivity abnormalities of brain networks in obsessive–compulsive disorder: a systematic review

Obsessive-compulsive disorder (OCD) is characterized by cognitive abnormalities encompassing several executive processes. Neuroimaging studies highlight functional abnormalities of executive fronto-parietal network (FPN) and default-mode network (DMN) in OCD patients, as well as of the prefrontal cortex (PFC) more specifically. We aim at assessing the presence of functional connectivity (FC) abnormalities of intrinsic brain networks and PFC in OCD, possibly underlying specific computational impairments and clinical manifestations. A systematic review of resting-state fMRI studies investigating FC was conducted in unmedicated OCD patients by querying three scientific databases (PubMed, Scopus, PsycInfo) up to July 2022 (search terms: “obsessive–compulsive disorder” AND “resting state” AND “fMRI” AND “function* *connect*” AND “task-positive” OR “executive” OR “central executive” OR “executive control” OR “executive-control” OR “cognitive control” OR “attenti*” OR “dorsal attention” OR “ventral attention” OR “frontoparietal” OR “fronto-parietal” OR “default mode” AND “network*” OR “system*”). Collectively, 20 studies were included. A predominantly reduced FC of DMN – often related to increased symptom severity – emerged. Additionally, intra-network FC of FPN was predominantly increased and often positively related to clinical scores. Concerning PFC, a predominant hyper-connectivity of right-sided prefrontal links emerged. Finally, FC of lateral prefrontal areas correlated with specific symptom dimensions. Several sources of heterogeneity in methodology might have affected results in unpredictable ways and were discussed. Such findings might represent endophenotypes of OCD manifestations, possibly reflecting computational impairments and difficulties in engaging in self-referential processes or in disengaging from cognitive control and monitoring processes.

Associations between anxiety, centromedial amygdala volume, and complex verbal fluency in middle-aged to older adults

Symptoms of anxiety are related to decreases in cognitive performance in middle-aged to older adults (i.e., ages 50 and older; MOA). Verbal fluency (VF), assessed with the Delis-Kaplan Executive Function System (D-KEFS) Category Switching (VF-CS) task, captures elements of executive function such as semantic memory, response initiation and inhibition, and cognitive flexibility. The present study examined the link between anxiety symptoms and VF-CS to better understand how this association affects such executive functions in MOA. We hypothesized that higher subclinical Beck Anxiety Inventory (BAI) scores would be associated with lower VF-CS. To further investigate the underlying neurobiological basis of an expected inverse relationship, total amygdala volume, centromedial amygdala (CMA) volume, and basolateral amygdala (BLA) volume were examined as they related to VF-CS scores on the D-KEFS. Based on extant research on connectivity and functioning between the CMA and BLA, we hypothesized that larger BLA volumes would be associated with lower anxiety scores and exhibit positive relationships with VF-CS. A sample of 63 MOA were recruited from the Providence, Rhode Island area as a part of a parent study on cardiovascular diseases. Participants completed self-report measures about physical and emotional health, a neuropsychological assessment, and a magnetic resonance imaging scan (MRI). Multiple hierarchical regressions were performed to examine relationships between variables of interest. Contrary to hypotheses, no significant relationship emerged between VF-CS and BAI scores, and BLA volume was not associated with either BAI scores or VF-CS. However, a significant positive relationship was observed between CMA volume and VF-CS. The significant relationship found between CMA and VF-CS may reflect the upward slope of the quadratic relationship between arousal and cognitive performance on the Yerkes-Dodson curve. These findings newly implicate CMA volume specifically as a possible neuromarker linking emotional arousal and cognitive performance in MOA.

Cannabidiol ameliorates the anxiogenic and compulsive-like behaviors induced by chronic consumption of a high-carbohydrate diet in male mice

The excessive consumption of ultra-processed foods and the development of obesity has been associated with several comorbidities, including psychiatric disorders. Excess fat tissue promotes a low-intensity inflammatory state, mainly in the white tissue, which is essential in developing metabolic alterations and influences brain homeostasis. In this scenario, Cannabidiol (CBD), a compound from Cannabis sativa, has presented anxiolytic and anti-inflammatory effects in murine models. This study verified whether CBD treatment would ameliorate the compulsive-like and anxiety-like behaviors observed after mice's chronic consumption of a high-refined carbohydrate (HC) diet. BALB/c male mice received a control or HC diet for 12 weeks followed by vehicle and CBD (30 mg/Kg, i.p.) administration, and their behavior was evaluated in the Marble Burying test (MB) and Novel Suppressing Feeding test (NSF). The sub-chronic, but not acute, treatment with CBD attenuated the compulsive-like and anxiogenic-like behavior induced by the HC diet. Our data reinforced the harmful effects of the HC diet's chronic consumption on compulsive and anxious behaviors and the potential of CBD as a drug treatment for psychiatric disorders associated with obesity.

Choice Type Impacts Human Reinforcement Learning

In reinforcement learning (RL) experiments, participants learn to make rewarding choices in response to different stimuli; RL models use outcomes to estimate stimulus-response values that change incrementally. RL models consider any response type indiscriminately, ranging from more concretely defined motor choices (pressing a key with the index finger), to more general choices that can be executed in a number of ways (selecting dinner at the restaurant). However, does the learning process vary as a function of the choice type? In Experiment 1, we show that it does: Participants were slower and less accurate in learning correct choices of a general format compared with learning more concrete motor actions. Using computational modeling, we show that two mechanisms contribute to this. First, there was evidence of irrelevant credit assignment: The values of motor actions interfered with the values of other choice dimensions, resulting in more incorrect choices when the correct response was not defined by a single motor action; second, information integration for relevant general choices was slower. In Experiment 2, we replicated and further extended the findings from Experiment 1 by showing that slowed learning was attributable to weaker working memory use, rather than slowed RL. In both experiments, we ruled out the explanation that the difference in performance between two condition types was driven by difficulty/different levels of complexity. We conclude that defining a more abstract choice space used by multiple learning systems for credit assignment recruits executive resources, limiting how much such processes then contribute to fast learning.

Emotional Schemas and Psychological Distress: Mediating Role of Resilience and Cognitive Flexibility

Objective: This study aimed to explore the structural relation of emotional schemas with psychological distress and evaluate the mediating role of resilience and cognitive flexibility in this relationship. Method : Participants were 300 students that voluntarily completed a questionnaire package that included the Leahy Emotional Schema Scale (LESS-P), Connor-Davidson Resilience Scale (CD-RISC), Cognitive Flexibility Inventory (CFI), and Depression Anxiety Stress Scale (DASS-21). Then, we utilized the LISREL software for structural equation modeling. Results: Structural equation modeling and path analysis revealed the direct effects of adaptive and maladaptive emotional schemas on psychological distress. The results indicated that maladaptive emotional schemas indirectly affected psychological distress via resilience and cognitive flexibility (P < 0.01). In contrast, adaptive emotional schemas indirectly affected psychological distress via cognitive flexibility rather than resilience (P < 0.05). Evaluation of the proposed structural model revealed an acceptable fit. Conclusion: The present research findings show the effect of emotional schemas on psychological distress via resilience and cognitive flexibility. Furthermore, the results suggest that resilience partially mediates the relationship between emotional schemas and psychological distress. At the same time, cognitive flexibility mediated this relationship.

Cognitive Neural Mechanism of Backward Inhibition and Deinhibition: A Review

Task switching is one of the typical paradigms to study cognitive control. When switching back to a recently inhibited task (e.g., “A” in an ABA sequence), the performance is often worse compared to a task without N-2 task repetitions (e.g., CBA). This difference is called the backward inhibitory effect (BI effect), which reflects the process of overcoming residual inhibition from a recently performed task (i.e., deinhibition). The neural mechanism of backward inhibition and deinhibition has received a lot of attention in the past decade. Multiple brain regions, including the frontal lobe, parietal, basal ganglia, and cerebellum, are activated during deinhibition. The event-related potentials (ERP) studies have shown that deinhibition process is reflected in the P1/N1 and P3 components, which might be related to early attention control, context updating, and response selection, respectively. Future research can use a variety of new paradigms to separate the neural mechanisms of BI and deinhibition.

Randomized trial of the efficacy of trial-based cognitive therapy for obsessive-compulsive disorder: preliminary findings

INTRODUCTION

Obsessive-compulsive disorder (OCD) is the fourth most prevalent mental disorder and is a disabling condition. OCD is associated with anatomical and functional changes in the brain, in addition to dysfunctional cognitions. The treatments of choice are selective serotonin reuptake inhibitors, cognitive-behavioral therapy (CBT), and exposure and response prevention (ERP). Trial-based cognitive therapy (TBCT) is a recent and empirically validated psychotherapy with a focus on restructuring dysfunctional negative core beliefs (CBs). The objective of this study was to evaluate the efficacy of TBCT relative to ERP for treatment of OCD.

METHOD

A randomized, single-blind clinical trial was conducted, randomizing 26 patients for individual treatment with TBCT (n = 12) or ERP (n = 14). The groups were evaluated at baseline, at the end of 3 months (12 sessions), and at 3, 6, and 12-month follow-ups.

RESULTS

Both approaches reduced the severity of symptoms with large effect sizes. These results were maintained at the 12-month follow-up assessment.

CONCLUSION

TBCT may be a valid and promising treatment for this disorder.

Cognitive Rigidity, Habitual Tendencies, and Obsessive-Compulsive Symptoms: Individual Differences and Compensatory Interactions

Recent theories have posited a range of cognitive risk factors for obsessive-compulsive disorder (OCD), including cognitive inflexibility and a maladaptive reliance on habits. However, empirical and methodological inconsistencies have obscured the understanding of whether inflexibility and habitual tendencies indeed shape OCD symptoms in clinical and sub-clinical populations, and whether there are notable interactions amongst these traits. The present investigation adopted an interactionist individual differences approach to examine the associations between behaviorally-assessed cognitive flexibility and subclinical OCD symptomatology in a healthy population. It also explored the nature of the interactions between cognitive flexibility and habitual tendencies, and the degree to which these cognitive traits predict subclinical OCD symptomatology. Across two studies, including a preregistration, Bayesian and regression analyses revealed that cognitive inflexibility and compulsive habitual tendencies act as unique and independent predictors of subclinical OCD symptomatology in healthy populations. Furthermore, there was a significant interaction between cognitive rigidity and habitual compulsivity, which accounted for 49.4% of the variance in subclinical OCD symptomatology in Study 1, and 37.3% in Study 2. In-depth analyses revealed a compensatory effect between cognitive inflexibility and habitual compulsivity such that both are necessary for OCD symptomatology, but neither is sufficient. These results imply that in order to generate reliable and nuanced models of the endophenotype of OCD symptomatology, it is essential to account for interactions between psychological traits. Moreover, the present findings have important implications for theories on the cognitive roots of OCD, and potentially in the development of interventions that target both cognitive inflexibility and habitual compulsivity.

A review of executive functioning challenges and strengths in autistic adults

Objective: There has been a steady rise in research characterizing executive functioning (EF) impairments in autistic individuals but limited research investigating EF strengths. This review provides a summary of current EF research in autistic adults with a focus on EF challenges and strengths and potential sources of heterogeneity in research findings. New avenues for addressing gaps in our understanding of EF strengths are proposed.Method: A review of the EF literature was conducted. One hundred twenty-four studies of inhibition, working memory, cognitive flexibility, fluency, planning, decision-making, and subjective measures of EF in autistic adults were included.Results: Autistic adults with average intellectual functioning demonstrate difficulties with cognitive flexibility, phonemic fluency, and working memory. Strengths in planning, decision-making, and semantic verbal fluency were evident in some but not all studies. Findings regarding inhibition are inconclusive. Key findings across each EF domain are discussed and sources of potential heterogeneity across studies were evaluated. The type of measure used appears to contribute to heterogeneous findings. Subjective EF measures revealed more consistent findings of deficits in autistic adults than objective EF measures.Conclusions: Research reveals areas of EF weaknesses as well as strengths in autistic adults. Unlike EF challenges, EF strengths are not well understood. Future research identifying EF strengths is needed to improve services and supports for autistic adults. Further investigation of potential factors that interact with or constrain EF such as comorbid disorders, verbal ability, sensory processing, and other factors specific to autism will be critical to move the field forward and increase understanding of how EF is related to everyday functioning in autistic adults.

Examining the roles of cognitive flexibility, emotion recognition, and metacognitions in adult Attention Deficit and Hyperactivity Disorder with predominantly inattentive presentation

The evaluation of cognitive functions in Attention Deficit and Hyperactivity Disorder (ADHD) is fundamental to improve the efficacy of therapeutic interventions. However, the role of specific higher-order cognitive functions in adult ADHD, including cognitive flexibility, emotion recognition, and metacognitions, remains unclear. Therefore, in the current study, we aimed to examine these three distinct higher-order cognitive functions among adult ADHD individuals. Forty patients with ADHD with predominantly inattentive presentation and 42 healthy controls participated in the study. The Adult Attention Deficit and Hyperactivity Disorder Scale (AADHDS), the Wisconsin Card Sorting Test (WCST), the Reading the Mind in the Eyes Test (RMET), and the Metacognitions Questionnaire-30 (MCQ-30) were administered. Results indicated that patients with ADHD had worse metacognitions scores, in specific subdimensions, relative to healthy controls. However, cognitive flexibility and emotion recognition did not differ between the groups. Moreover, the cognitive confidence subdimension of the MCQ-30 was found to be sole significant predictor in the attention deficit subdimension of the AADHDS. Our findings suggest that lack of cognitive confidence may contribute to ADHD symptomatology despite regularly functioning cognitive flexibility and emotion recognition. Therefore, metacognitions could be a suitable target to alleviate the severity of ADHD symptoms.

Coping strategies in obsessive-compulsive patients during Covid-19 lockdown

The main aim of this study was to compare coping strategies in obsessive-compulsive disorder (OCD) patients and a healthy control group during COVID-19 lockdown and to analyze the relationship with some variables which may influence results (depression, anxiety, comorbidity, subtype of obsession-compulsion).

METHOD

There were 237 participants, 122 OCD and 115 healthy controls, aged 17-61 years old (M = 33.48, SD = 11.13).

RESULTS

Groups showed differences in the use of some adaptive strategies (positive reinterpretation, acceptance, humor) and maladaptive (denial, self-blame). Within obsessive-compulsive group, comorbidity affected the greater use of inappropriate strategies (denial, substance abuse and self-blame) while type of obsession-compulsion did not influence use. Anxiety and depression levels were related to the use of less adaptive strategies.

CONCLUSIONS

These findings strengthen the need for training in the use of effective and adaptive coping strategies, making it necessary to improve clinical follow-up of these patients. It is relevant to be in contact with healthcare professionals, review medication and observe the anxiety and depression levels.

Response Inhibition, Cognitive Flexibility and Working Memory in Obsessive-Compulsive Disorder, Generalized Anxiety Disorder and Social Anxiety Disorder

This study analyzed response inhibition, cognitive flexibility and working memory in three groups of patients diagnosed with obsessive-compulsive disorder, social anxiety disorder and generalized anxiety disorder, considering some variables that may influence results (nonverbal reasoning, comorbidity, use of pharmacotherapy). Neuropsychological measures were completed using a computerized Wisconsin card sorting test, Stroop color word test, go/no-go task, digits and Corsi. Significant differences were obtained among groups in cognitive flexibility and working memory variables. The obsessive-compulsive disorder (OCD) group showed the worst results. The social anxiety disorder group obtained greater effect sizes in visuospatial memory. However, significant differences between groups in visuospatial memory were no longer present when nonverbal reasoning was controlled. Comorbidity influenced interference in the OCD and generalized anxiety disorder (GAD) groups. In addition, the executive functions were differently influenced by the level of obsessions and anxiety, and the use of pharmacotherapy. Study limitations include a non-random selection of participants, modest sample size and design type (cross-sectional). The OCD group showed the worst results in flexibility cognitive and verbal working memory. Comorbidity, use of pharmacotherapy and level anxiety and obsessions were variables influencing the performance of executive functions.

Executive Functioning and Clinical Variables in Patients with Obsessive-Compulsive Disorder

Background: Cognitive flexibility, response inhibition, and working memory are considered the main mechanisms responsible for executive control. This study examined differences in cognitive flexibility, inhibition, and working memory in patients with obsessive–compulsive disorder (OCD) relative to a control group. Method: A total of 62 obsessive-compulsive participants (OCD = 32; healthy control = 32) aged between 17 and 56 years old (M = 33.16, SD = 9.23) were administered the computerized Wisconsin Card Sorting Test, Stroop Color–Word Test, Go/No-Go Task, Digit Test, and Corsi Block Test. Clinician-rated and self-reported obsessive–compulsive symptom severity, and anxiety, depression, and obsessive beliefs were evaluated. Results: The control group performed better than the OCD group in tasks involving cognitive flexibility, inhibition, and visuospatial working memory. Anxiety and obsessive beliefs influenced the participants’ performance on inhibition and working memory tasks. Similarly, comorbidity also influenced inhibition and working memory. In addition, the use of pharmacotherapy and the degree of OCD symptom severity influenced verbal working memory. Conclusions: Cognitive flexibility, inhibition, and visuospatial working memory deficits may be endophenotypes of OCD but require further examination for specificity. OCD severity, comorbidity patterns, anxiety, and obsessive beliefs may influence performance.

Reasoning, problem-solving, and visual learning as candidate endophenotypes for first-episode, drug-naïve obsessive-compulsive disorder in the Han Chinese population

BACKGROUND

Obsessive-compulsive disorder (OCD) is a mental disease with obsessions and compulsions as its main symptom dimensions. In recent years, endophenotype (intermediate phenotype) method has been used to study OCD. This study aimed to evaluate the cognitive function for patients with OCD and search for possible endophenotype.

METHODS

This study utilized a comparison control group design with 64 OCD patients, 49 healthy siblings (HS) of the patients, and 53 healthy controls. Several projects were selected to evaluate patients' cognition functions, such as reasoning, problem-solving, attention/vigilance, visual learning, speed of processing, and verbal learning.

RESULTS

Results suggested that the patients with OCD and their HS have cognitive deficits in reasoning, problem-solving, trail making test, and visual learning. Significant differences were observed among the three groups of subjects in verbal learning. No significant difference was observed in attention/vigilance among the three groups.

CONCLUSIONS

Our results suggest that reasoning, problem-solving, and visual learning may be candidate endophenotypes for the early diagnosis of prodrome Han Chinese patients with OCD.

Functional Connectivity Changes in Obsessive-Compulsive Disorder Correspond to Interference Control and Obsessions Severity

Introduction: Deficits in neurocognitive mechanisms such as inhibition control and cognitive flexibility have been suggested to mediate the symptoms in obsessive-compulsive disorder (OCD). These mechanisms are proposedly controlled by the "affective" and "executive" orbitofronto-striato-thalamo-cortical (CSTC) circuits with well-documented morphological and functional alterations in OCD that are associated with OCD symptoms. The precuneus region has been suggested in OCD as another key structure associated with the mechanism of "thought-action fusion." Our study aimed to elucidate the association of the altered functional coupling of the CSTC nodes (and precuneus), the OCD symptoms, and interference control/cognitive flexibility. Methods: In a group of 36 (17 medicated and 19 drug-free) OCD patients and matched healthy volunteers, we tested functional connectivity (FC) within the constituents of the dorsolateral prefrontal cortex "executive" CSTC, the orbitofrontal cortex/anterior cingulate "affective" CSTC, and precuneus. The functional connections showing the strongest effects were subsequently entered as explanatory variables to multiple regression analyses to identify possible associations between observed alterations of functional coupling and cognitive (Stroop test) and clinical measures (obsessions, compulsions, and anxiety level). Results: We observed increased FC (FWE p < 0.05 corr.) between CSTC seeds and regions of the parieto-occipital cortex, and between the precuneus and the angular gyrus and dorsolateral prefrontal cortex. Decreased FC was observed within the CSTC loop (caudate nucleus and thalamus) and between the anterior cingulate cortex and the limbic lobe. Linear regression identified a relationship between the altered functional coupling of thalamus with the right somatomotor parietal cortex and the Stroop color-word score. Similar association of thalamus FC has been identified also for obsessions severity. No association was observed for compulsions and anxiety. Conclusions: Our findings demonstrate altered FC in OCD patients with a prevailing increase in FC originating in CSTC regions toward other cortical areas, and a decrease in FC within the constituents of CSTC loops. Moreover, our results support the role of precuneus in OCD. The association of the cognitive and clinical symptoms with the FC between the thalamus and somatomotor cortex indicates that cognitive flexibility and inhibitory control are strongly linked and both mechanisms might contribute to the symptomatology of OCD.

Effects of Trazodone on Sleep Quality and Cognitive Function in Arteriosclerotic Cerebral Small Vessel Disease Comorbid With Chronic Insomnia

BACKGROUND

Chronic insomnia is common in patients with arteriosclerotic cerebral small vessel disease (CSVD) and aggravates the cognitive impairment caused by CSVD. Low-dose trazodone is effective in treating insomnia, but it is unclear whether it can also improve cognitive function in CSVD patients. This study was performed to explore the effects of trazodone on sleep quality and cognitive function in CSVD comorbid with chronic insomnia.

METHODS

This was a randomized, double-blind, placebo-controlled pilot study. Forty patients suffering from arteriosclerotic CSVD and insomnia were recruited from an outpatient clinic. Participants were randomized individually to receive either trazodone (study group) or a placebo (control group) for 4 weeks. The primary outcome was the cognitive score on the Montreal Cognitive Assessment scale (MoCA). Secondary outcomes included sleep parameters measured with polysomnography (PSG) and the Pittsburgh Sleep Quality Index.

RESULTS

Trazodone caused significantly better improvements in concentration and recall abilities, measured with MoCA, as well as in PSG parameters such as sleep efficiency, N3 sleep ratio, and sleep continuity than the placebo, with no significant differences in the occurrence of side effects. The improvement of sleep quality was correlated with increased concentration and recall abilities.

CONCLUSIONS

A low dose of trazodone seems acceptable and effective in reducing insomnia severity and improving concentration and recall abilities in this pilot study. The improvement of cognition could be achieved by alleviation of insomnia severity. Considering the high incidence of insomnia in CSVD patients, the results of this preliminary study support the use of low-dose trazodone to deal with insomnia and cognitive impairment in CSVD.