Cognitive Dysfunction in Obsessive-Compulsive Disorder

Externally orienting cues improve cognitive control in OCD

BACKGROUND AND OBJECTIVES

An executive overload model of obsessive-compulsive disorder (OCD) posits that broad difficulties with executive functioning in OCD result from an overload on the executive system by obsessive thoughts. It implies that, if individuals with OCD "snap out" of their obsessive thoughts, their performance on neurocognitive tasks will improve.

METHODS

We test this prediction using the revised Attention Network Test, ANT-R, and distinct subsamples of data from unmedicated OCD and healthy controls (HC). ANT-R includes Simon and Flanker tasks; in both, incongruent trials take longer to resolve ('conflict costs'). On some trials, a warning cue helps participants to respond faster ('alerting benefits'). In OCD (N = 34) and HC (N = 46), matched on age, IQ, and sex, we tested (1) the effect of OCD on alerting benefits, and (2) the effect of OCD on warning cue related reductions in conflict costs. In a distinct subsample of OCD (N = 32) and HC (N = 51), we assessed whether alerting benefits and cue-related reductions in conflict costs are associated differently with different OCD symptoms.

RESULTS

A warning cue can help individuals with OCD more than HC to improve performance on Simon and Flanker tasks. This effect is positively associated with severity of contamination symptoms.

LIMITATIONS

This study did not directly assess how distracted participants are by obsessive thoughts. It relied on the ANT-R subtraction measures. Symptom severity was assessed using self-report measures.

CONCLUSIONS

Difficulties in resolving conflict during decision-making in OCD can be modulated by a warning cue presented immediately before an attentional task.

Targeting the prefrontal-supplementary motor network in obsessive-compulsive disorder with intensified electrical stimulation in two dosages: a randomized, controlled trial

Obsessive-compulsive disorder (OCD) is associated with a high disease burden, and treatment options are limited. We used intensified electrical stimulation in two dosages to target a main circuitry associated with the pathophysiology of OCD, left dorsolateral prefrontal cortex (l-DLPFC), and pre-supplementary motor area (pre-SMA) and assessed clinical outcomes, neuropsychological performance, and brain physiology. In a double-blind, randomized controlled trial, thirty-nine patients with OCD were randomly assigned to three groups of sham, 2-mA, or 1-mA transcranial direct current stimulation (tDCS) targeting the l-DLPFC (F3) and pre-SMA (FC2) with anodal and cathodal stimulation respectively. The treatment included 10 sessions of 20-minute stimulation delivered twice per day with 20-min between-session intervals. Outcome measures were reduction in OCD symptoms, anxiety, and depressive states, performance on a neuropsychological test battery (response inhibition, working memory, attention), oscillatory brain activities, and functional connectivity. All outcome measures except EEG were examined at pre-intervention, post-intervention, and 1-month follow-up times. The 2-mA protocol significantly reduced OCD symptoms, anxiety, and depression states and improved quality of life after the intervention up to 1-month follow-up compared to the sham group, while the 1-mA protocol reduced OCD symptoms only in the follow-up and depressive state immediately after and 1-month following the intervention. Both protocols partially improved response inhibition, and the 2-mA protocol reduced attention bias to OCD-related stimuli and improved reaction time in working memory performance. Both protocols increased alpha oscillatory power, and the 2-mA protocol decreased delta power as well. Both protocols increased connectivity in higher frequency bands at frontal-central areas compared to the sham. Modulation of the prefrontal-supplementary motor network with intensified tDCS ameliorates OCD clinical symptoms and results in beneficial cognitive effects. The 2-mA intensified stimulation resulted in larger symptom reduction and improved more converging outcome variables related to therapeutic efficacy. These results support applying the intensified prefrontal-SMA tDCS in larger trials.

Reduced Expression of the Htr2a, Grin1, and Bdnf Genes and Cognitive Inflexibility in a Model of High Compulsive Rats

Compulsivity is a core symptom in different psychopathological disorders, characterized by excessive behaviors and behavioral inflexibility. The selection of high drinker (HD) versus low drinker (LD) rats by schedule-induced polydipsia (SIP) is a valid model for studying the compulsive phenotype. The compulsive HD rats showed cognitive inflexibility and reduced serotonin 2A (5-HT2A) receptor binding levels in the frontal cortex (FC). According to that, we hypothesize that compulsive HD rats might have an alteration in the cognitive control domain regarding inflexibility, assessed by spatial memory on the Morris Water Maze (MWM), working and reference memory by the Radial Arm Maze, and behavioral deficits in stimulus processing by the Novel Object Recognition test. The possible underlying mechanisms might be linked to the brain gene expression of 5HT2A, 5HT2C, glutamate NMDA receptors, and brain-derived neurotrophic factor (BDNF) in FC, hippocampus, and amygdala. HD rats confirmed a cognitive inflexibility profile on the reversal condition in the MWM compared to LD rats, while no differences were observed on stimulus processing, spatial, and working memory. Moreover, HD rats showed a reduced expression of the Htr2a, Grin1, and Bdnf genes in FC. Furthermore, there was a negative correlation between the relative expression of the Htr2a, Grin1, and Bdnf genes in FC and the level of compulsive water intake in HD rats on SIP. These data reveal that cognitive inflexibility may not be associated with a memory or stimulus processing deficit in compulsive individuals but may result by a region-specific alteration of the Htr2a, Grin1, and Bdnf gene expression in FC.

Disgust-reduction evaluative conditioning (DREC) and brain stimulation in patients with contamination-based obsessive-compulsive disorder: a protocol for a randomized control trial

BACKGROUND

The negative emotional valence of a stimulus can be altered if paired with a pleasant stimulus, a phenomenon referred to as evaluative conditioning. Disgust, as a central emotion in obsessive-compulsive disorder (OCD), particularly in the contamination subtype, may be an appropriate target for such a method. We know that disgust processing and OCD pathophysiology share in some brain areas, including the orbitofrontal cortex, as the neuromodulation techniques targeted in this area have been able to decrease OCD symptoms. We aim to conduct a randomized clinical trial to investigate the evaluative conditioning effect on disgust reduction in patients with contamination-based OCD when administered with or without neuromodulation targeted orbitofrontal cortex.

METHOD

In a single-blind randomized control trial (RCT), 55 patients with contamination-based OCD will be randomly assigned to four arms. In a factorial design, they will receive 10 sessions of evaluative conditioning training (either sham or real) plus cathodal transcranial direct current stimulation (tDCS) over the orbitofrontal cortex (either sham or real). The intensity of disgust experience and clinical symptoms will be investigated as primary outcomes and quantitative electroencephalogram and cognitive functions as secondary outcomes. The data will be collected at three assessment levels: baseline, after completing intervention sessions, and 2-month follow-up.

DISCUSSION

The present RCT is the first study that applies evaluative conditioning training in the OCD clinical sample. It will clarify the effect of the evaluative conditioning method alone and with tDCS on disgust reduction in patients with contamination-based OCD. It will provide initial evidence for such an emotion modulation method in the OCD population. The effect of this emotion-focused protocol on cognitive functions and electroencephalogram components is also of interest.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05907369. Registered on 16 June 2023. Retrospectively registered.

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.

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.

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.

Disruption of Astrocyte-Dependent Dopamine Control in the Developing Medial Prefrontal Cortex Leads to Excessive Grooming in Mice

BACKGROUND

Astrocytes control synaptic activity by modulating perisynaptic concentrations of ions and neurotransmitters including dopamine (DA) and, as such, could be involved in the modulating aspects of mammalian behavior.

METHODS

We produced a conditional deletion of the vesicular monoamine transporter 2 (VMAT2) specifically in astrocytes (aVMTA2cKO mice) and studied the effects of the lack of VMAT2 in prefrontal cortex (PFC) astrocytes on the regulation of DA levels, PFC circuit functions, and behavioral processes.

RESULTS

We found a significant reduction of medial PFC (mPFC) DA levels and excessive grooming and compulsive repetitive behaviors in aVMAT2cKO mice. The mice also developed a synaptic pathology, expressed through increased relative AMPA versus NMDA receptor currents in synapses of the dorsal striatum receiving inputs from the mPFC. Importantly, behavioral and synaptic phenotypes were rescued by re-expression of mPFC VMAT2 and L-DOPA treatment, showing that the deficits were driven by mPFC astrocytes that are critically involved in developmental DA homeostasis. By analyzing human tissue samples, we found that VMAT2 is expressed in human PFC astrocytes, corroborating the potential translational relevance of our observations in mice.

CONCLUSIONS

Our study shows that impairment of the astrocytic control of DA in the mPFC leads to symptoms resembling obsessive-compulsive spectrum disorders such as trichotillomania and has a profound impact on circuit function and behaviors.

Similarities and differences in working memory and neurometabolism of obsessive-compulsive disorder and major depressive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) and major depressive disorder (MDD) both showed cognitive impairment, and the altered neurometabolic may associate with cognitive impairment. However, there are limited comparative working memory (WM) and neuroimaging studies on these two disorders. Therefore, we investigated the characteristics of WM and neurometabolic changes in patients with OCD and MDD.

METHODS

A total of 64 unmedicated patients (32 OCD and 32 MDD), and 33 healthy controls (HC) were included to conduct WM assessment comprising Digit Span Test (DST), 2-back task and Stroop Color and Word Test (SCWT). Additionally, all subjects underwent protons magnetic resonance spectroscopy (¹H-MRS) to collect neurometabolic ratios of N-acetyl aspartate (NAA) and choline-containing compounds (Cho) to creatine (Cr) in the prefrontal cortex (PFC) and lentiform nucleus (LN). Finally, differential and correlation analysis were conducted to investigate their characteristics and relationships.

RESULTS

Compared with HC, both OCD and MDD patients exhibited a lower accuracy rate in the 2-back task, and only MDD patients performed worse in DST scores and longer reaction times in SCWT (all p < 0.05). Both OCD and MDD patients had lower NAA/Cr ratios in bilateral PFC (all p < 0.05). And the decreased NAA/Cr ratios in right PFC were positively correlated to DST scores in MDD group (r = 0.518, p = 0.003).

CONCLUSIONS

Both OCD and MDD showed WM impairment and neurometabolic alterations in PFC. Besides, MDD performed more severe and broader WM impairment compared to OCD. Moreover, the dysfunction of PFC may underlie the neural basis of WM impairment in MDD.

The metacontrol hypothesis as diagnostic framework of OCD and ADHD: A dimensional approach based on shared neurobiological vulnerability

Obsessive-compulsive disorder (OCD) and attention-deficit hyperactivity disorder (ADHD) are multi-faceted neuropsychiatric conditions that in many aspects appear to be each other's antipodes. We suggest a dimensional approach, according to which these partially opposing disorders fall onto a continuum that reflects variability regarding alterations of cortico-striato-thalamo-cortical (CSTC) circuits and of the processing of neural noise during cognition. By using theoretical accounts of human cognitive metacontrol, we develop a framework according to which OCD can be characterized by a chronic bias towards exaggerated cognitive persistence, equivalent to a high signal-to-noise ratio (SNR)-which facilitates perseverative behaviour but impairs mental flexibility. In contrast, ADHD is characterized by a chronic bias towards inflated cognitive flexibility, equivalent to a low SNR-which increases behavioural variability but impairs the focusing on one goal and on relevant information. We argue that, when pharmacology is not feasible, novel treatments of these disorders may involve methods to manipulate the signal-to-noise ratio via non-invasive brain stimulation techniques, in order to normalize the situational imbalance between cognitive persistence and cognitive flexibility.

Cognitive Remediation in Psychiatric Disorders: State of the Evidence, Future Perspectives, and Some Bold Ideas

Many people with psychiatric disorders experience impairments in cognition. These deficits have a significant impact on daily functioning and sometimes even on the further course of their disease. Cognitive remediation (CR) is used as an umbrella term for behavioral training interventions to ameliorate these deficits. In most but not all studies, CR has proven effective in improving cognition and enhancing everyday functional outcomes. In this paper, after quickly summarizing the empirical evidence, practical advice to optimize the effects of CR interventions is provided. We advocate that CR interventions should be as fun and motivating as possible, and therapists should at least consider using positively toned emotional stimuli instead of neutral stimuli. Participants should be screened for basic processing deficits, which should be trained before CR of higher-order cognitive domains. CR should stimulate metacognition and utilize natural settings to invoke social cognition. Wherever possible, CR tasks should link to tasks that participants face in their everyday life. Therapists should consider that participants might also benefit from positive side effects on symptomatology. Finally, the CR approach might even be utilized in settings where the treatment of cognitive impairments is not a primary target.

Functional interventions as augmentation strategies for obsessive-compulsive disorder (OCD): scoping review and expert survey from the international college of obsessive-compulsive spectrum disorders (ICOCS)

BACKGROUND

Patients with obsessive-compulsive disorder (OCD) commonly exhibit a range of functional difficulties, presumed linked to neurocognitive changes. Evidence-based first-line treatments have limited effect on improving these cognitive-functional problems. Candidate interventions could be used to augment evidence-based treatments by the multi-professional mental health team.

METHODS

A scoping review was performed to identify any intervention with at least one peer-reviewed report of clinical improvement in any of the 13 functional domains of the Cognitive Assessment Instrument of Obsessions and Compulsions (CAIOC-13). Next, an online survey of experts of the International College of Obsessive-Compulsive Spectrum Disorders was conducted.

RESULTS

Forty-four studies were identified reporting a positive outcome for 27 different kinds of intervention. Twenty-six experts from 12 different countries, including at least one expert from each continent, completed the opinion survey. Five interventions were identified as 'highly promising', none of which was moderated by rater-related factors, suggesting global applicability.

CONCLUSION

Patients with OCD may benefit from a detailed functional assessment, to identify areas of unmet need. A variety of interventions show theoretical promise for treating the complex functional difficulties in OCD as adjuncts to first-line treatments, but the published evidence is weak. Randomised controlled trials are needed to determine the clinical effectiveness of these interventions.HighlightsFunctional-cognitive problems are common in patients with OCD.First-line evidence-based treatments have limited effect on these functionalcognitive difficulties.In our scoping review we found 44 studies reporting of improved clinical outcomes in any of the 13 functional domains of the Cognitive Assessment Instrument of Obsessions and Compulsions (CAIOC-13).An online survey of experts of the International College of Obsessive-Compulsive Spectrum Disorders (ICOCS) was conducted and identified five interventions as "highly promising" candidate treatments for functional-cognitive problems in OCD.Randomised controlled trials are needed to determine the clinical effectiveness of these interventions.

Validity and utility of Hierarchical Taxonomy of Psychopathology (HiTOP): III. Emotional dysfunction superspectrum

The Hierarchical Taxonomy of Psychopathology (HiTOP) is a quantitative nosological system that addresses shortcomings of traditional mental disorder diagnoses, including arbitrary boundaries between psychopathology and normality, frequent disorder co-occurrence, substantial heterogeneity within disorders, and diagnostic unreliability over time and across clinicians. This paper reviews evidence on the validity and utility of the internalizing and somatoform spectra of HiTOP, which together provide support for an emotional dysfunction superspectrum. These spectra are composed of homogeneous symptom and maladaptive trait dimensions currently subsumed within multiple diagnostic classes, including depressive, anxiety, trauma-related, eating, bipolar, and somatic symptom disorders, as well as sexual dysfunction and aspects of personality disorders. Dimensions falling within the emotional dysfunction superspectrum are broadly linked to individual differences in negative affect/neuroticism. Extensive evidence establishes that dimensions falling within the superspectrum share genetic diatheses, environmental risk factors, cognitive and affective difficulties, neural substrates and biomarkers, childhood temperamental antecedents, and treatment response. The structure of these validators mirrors the quantitative structure of the superspectrum, with some correlates more specific to internalizing or somatoform conditions, and others common to both, thereby underlining the hierarchical structure of the domain. Compared to traditional diagnoses, the internalizing and somatoform spectra demonstrated substantially improved utility: greater reliability, larger explanatory and predictive power, and greater clinical applicability. Validated measures are currently available to implement the HiTOP system in practice, which can make diagnostic classification more useful, both in research and in the clinic.

Neurobiological Highlights of Cognitive Impairment in Psychiatric Disorders

This review is focused on several psychiatric disorders in which cognitive impairment is a major component of the disease, influencing life quality. There are plenty of data proving that cognitive impairment accompanies and even underlies some psychiatric disorders. In addition, sources provide information on the biological background of cognitive problems associated with mental illness. This scientific review aims to summarize the current knowledge about neurobiological mechanisms of cognitive impairment in people with schizophrenia, depression, mild cognitive impairment and dementia (including Alzheimer's disease).The review provides data about the prevalence of cognitive impairment in people with mental illness and associated biological markers.

P300 and delay-discounting in obsessive-compulsive disorder

Previous research showed that dysfunctions of fronto-striatal neural networks are implicated in the pathophysiology of obsessive-compulsive disorder (OCD). Accordingly, patients with OCD showed altered performances during decision-making tasks. As P300, evoked by oddball paradigms, is suggested to be related to attentional and cognitive processes and generated in the medial temporal lobe and orbitofrontal and cingulate cortices, it is of special interest in OCD research. Therefore, this study aimed to investigate P300 in OCD and its associations with brain activity during decision-making: P300, evoked by an auditory oddball paradigm, was analysed in 19 OCD patients and 19 healthy controls regarding peak latency, amplitude and source density power in parietal cortex areas by sLORETA. Afterwards, using a fMRI paradigm, Blood-oxygen-level-dependent (BOLD) contrast imaging was conducted during a delay-discounting paradigm. We hypothesised differences between groups regarding P300 characteristics and associations with frontal activity during delay-discounting. The P300 did not differ between groups, however, the P300 latency over the P4 electrode correlated negatively with the NEO-FFI score openness to experience in patients with OCD. In healthy controls, P300 source density power correlated with activity in frontal regions when processing rewards, a finding which was absent in OCD patients. To conclude, associations of P300 with frontal brain activation during delay-discounting were found, suggesting a contribution of attentional or context updating processes. Since this association was absent in patients with OCD, the findings could be interpreted as being indeed related to dysfunctions of fronto-striatal neural networks in patients with OCD.

Inverse Association Between Resting-State Putamen Activity and Iowa Gambling Task Performance in Patients With Obsessive-Compulsive Disorder and Control Subjects

BACKGROUND

Symptoms of obsessive-compulsive disorder (OCD) have been conceptualized as manifestations of decision-making deficits. Patients with OCD exhibit impairment during the decision-making process, as assessed by the Iowa Gambling Task (IGT). This impairment is independent of clinical severity and disease progression. However, the association between the decision-making deficit and resting-state brain activity of patients with OCD has not been examined.

METHODS

Fifty unmedicated patients with OCD and 55 matched control subjects completed IGT. Resting-state brain activity was examined using the fractional amplitude of low-frequency fluctuations (fALFFs). fALFF analysis focused on the slow-4 and 5 bands. Group comparisons were performed to determine the association between IGT performance and fALFFs.

RESULTS

There was a significant group difference in the association between the IGT total net score and slow-4 fALFFs in the left putamen (voxel height threshold of p < 0.001; cluster size threshold of p < 0.05; family wise error-corrected). Higher putamen slow-4 fALFFs were correlated with lower IGT scores for OCD patients (r = -0.485; p < 0.0005) and higher IGT scores for control subjects (r = 0.402; p < 0.005). There was no group difference in the association between the IGT total net score and slow-5 fALFFs.

CONCLUSIONS

These findings in unmedicated patients demonstrate the importance of resting-state putamen activity for decision-making deficit associated with OCD, as measured by IGT. The inverse correlation may be explained by the hypersensitive response of the putamen in patients with OCD.

Effect of modified electroconvulsive therapy on neuro metabolites and magnetic resonance spectroscopy imaging signals in patients with refractory obsessive-compulsive disorder

OBJECTIVE

This study was aimed to investigate the effect of modified electroconvulsive therapy (MECT) on neurometabolites and magnetic resonance spectroscopy imaging (MRSI) signals in patients with refractory obsessive-compulsive disorder (OCD).

METHODS

From January 2018 to January 2020, 64 patients with OCD consecutively treated in the Psychiatric Department of our hospital were randomly divided into a study group treated with MECT and a control group treated with drugs alone. The obsessive-compulsive state, anxiety and depression, MRSI signals, neuro metabolite ratio, and quality of life were all observed in both groups.

RESULTS

After treatment, the scores of compulsive behaviors, obsessive thoughts, Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Hamilton Anxiety Scale (HAMA), and Hamilton Depression Scale (HAMD) in the study group were lower than those of the control group. The N-acetylaspartate to creatine ratio (NAA/Cr) value was increased in the study group while it was decreased in the control group. In addition, the choline/creatine (Cho/Cr) ratio was decreased in the study group, whereas it was increased in the control group (P < 0.05). Compared to the control group, the study group's social and physiological functions, role limitations, and overall health scores were significantly higher. The amplitudes of low-frequency fluctuations were reduced considerably following MECT treatment in the right anterior cerebellar lobe, left inferior parietal lobule, right paracentral lobule, and right precentral gyrus.

CONCLUSIONS

MECT can effectively relieve obsessive-compulsive symptoms, regulate neuro metabolite levels, improve quality of life, reduce anxiety and depression, and is linked to changes in right brain functional activities.

Gray Matter Alterations in Pediatric Schizophrenia and Obsessive-Compulsive Disorder: A Systematic Review and Meta-Analysis of Voxel-Based Morphometry Studies

OBJECTIVE

The aim of this study is comparing gray matter alterations in SCZ pediatric patients with those suffering from obsessive-compulsive disorder (OCD) based on a systematic review and an activation likelihood estimation (ALE) meta-analysis.

METHODS

A systematic literature search was performed in PubMed, Elsevier, and China National Knowledge Infrastructure (CNKI). A systematic review and an ALE meta-analysis were performed to quantitatively examine brain gray matter alterations.

RESULTS

Children and adolescents with schizophrenia had decreased gray matter volume (GMV) mainly in the prefrontal cortex (PFC), temporal cortex (such as the middle temporal gyrus and transverse temporal gyrus), and insula, while children and adolescents with OCD mainly had increased GMV in the PFC and the striatum (including the lentiform nucleus and caudate nucleus), and decreased GMV in the parietal cortex.

CONCLUSIONS

Our results suggest that gray matter abnormalities in the PFC may indicate homogeneity between the two diseases. In children and adolescents, structural alterations in schizophrenia mainly involve the fronto-temporal and cortico-insula circuits, whereas those in OCD mainly involve the prefrontal-parietal and the prefrontal-striatal circuits.

Compulsions without obsession following stroke

BACKGROUND

Obsessive-compulsive disorder (OCD) is characterized by intrusive and irrational thoughts as well as repetitive behaviours. OCD-like behaviours have been described in a wide range of neurological disorders. In cerebrovascular accidents, the semiology arises mostly from lesions to the basal ganglia - though cortical regions may also be involved. In the past few years, the mechanisms underlying OCD in psychiatric patients have been re-examined, in particular the functional relationship between anxiety, obsessions and compulsions. Traditionally, obsessions are viewed as a trigger for compulsive behaviour that represents an attempt to reduce anxiety. By contrast, other models place compulsions - as a manifestation of an imbalance between goal-directed action and automatic habits that leads to maladaptive habit learning - at the core of OCD.

CASE

We show neurological evidence of pure compulsions without obsession in a patient following stroke in the left subcortical regions. Furthermore, we present comprehensive neuropsychological findings that identify specific alterations across executive and emotional domains. Finally, MRI analyses reveal that the subcortical stroke had resulted in a strong decrease of connectivity suggestive of large network alterations.

CONCLUSIONS

Our case provides direct information on how brain structure and function relate in an OCD patient, highlighting the central role of compulsions in the pathology.

Cognitive deficits and clinical symptoms in patients with treatment-refractory obsessive-compulsive disorder: The role of slowness in information processing

Patients with Obsessive-Compulsive Disorder (OCD) present neuropsychological deficits across different cognitive domains, especially in executive functioning and information processing speed. Some studies have even suggested that speed deficits may underlie poor neuropsychological performance. However, this hypothesis remains unanswered in both OCD general population and OCD refractory subgroup. In addition, it is not clear whether such deficits are secondary to the clinical symptoms or may constitute a primary deficit. The aim of this study was to explore the speed of processing hypothesis in treatment-refractory OCD patients, and to clarify to what extent slowness is related to psychopathological symptoms. Both clinical and neuropsychological examination was conducted to assess 39 OCD refractory patients candidates for neurosurgery and 39 healthy matched individuals. Principal component analysis revealed a three-component structure in the neuropsychological battery being used, including a speed of processing, working memory, and conflict monitoring components. Group comparisons revealed that OCD patients performed significantly worse than healthy individuals in speed measures, but no differences were found in executive tests not influenced by time. Correlation analyses revealed a lack of association between neuropsychological and clinical measures. The results suggest that treatment-refractory OCD patients exhibit a primary deficit in information processing speed independent of clinical symptoms.

Knowledge and competency standards for specialized cognitive behavior therapy for adult obsessive-compulsive disorder

Obsessive-Compulsive Disorder (OCD) is a leading cause of disability world-wide (World Health Organization, 2008). Treatment of OCD is a specialized field whose aim is recovery from illness for as many patients as possible. The evidence-based psychotherapeutic treatment for OCD is specialized cognitive behavior therapy (CBT, NICE, 2005, Koran and Simpson, 2013). However, these treatments are not accessible to many sufferers around the world. Currently available guidelines for care are deemed to be essential but insufficient because of highly variable clinician knowledge and competencies specific to OCD. The phase two mandate of the 14 nation International OCD Accreditation Task Force (ATF) created by the Canadian Institute for Obsessive Compulsive Disorders is development of knowledge and competency standards for specialized treatments for OCD through the lifespan deemed by experts to be foundational to transformative change in this field. This paper presents knowledge and competency standards for specialized CBT for adult OCD developed to inform, advance, and offer a model for clinical practice and training for OCD. During upcoming ATF phases three and four criteria and processes for training in specialized treatments for OCD through the lifespan for certification (individuals) and accreditation (sites) will be developed based on the ATF standards.

Gray Matter Abnormalities of Orbitofrontal Cortex and Striatum in Drug-Naïve Adult Patients With Obsessive-Compulsive Disorder

Objective: This study examined whether obsessive-compulsive disorder (OCD) patients have gray matter abnormalities in regions related to executive function, and whether such abnormalities are associated with impaired executive function. Methods: Multiple scales were administered to 27 first-episode drug-naïve OCD patients and 29 healthy controls. Comprehensive brain morphometric indicators of orbitofrontal cortex (OFC) and three striatum areas (caudate, putamen, and pallidum) were determined. Hemisphere lateralization index was calculated for each region of interest. Correlations between lateralization index and psychological variables were examined in OCD group. Results: The OCD group had greater local gyrification index for the right OFC and greater gray matter volumes of the bilateral putamen and left pallidum than healthy controls. They also had weaker left hemisphere superiority for local gyrification index of the OFC and gray matter volume of the putamen, but stronger left hemisphere superiority for gray matter volume of the pallidum. Patients' lateralization index for local gyrification index of the OFC correlated negatively with Yale-Brown Obsessive Compulsive Scale and Dysexecutive Questionnaire scores, respectively. Conclusion: Structural abnormalities of the bilateral putamen, left pallidum, and right OFC may underlie OCD pathology. Abnormal lateralization in OCD may contribute to the onset of obsessive-compulsive symptoms and impaired executive function.

Nucleus Accumbens Stimulation Modulates Inhibitory Control by Right Prefrontal Cortex Activation in Obsessive-Compulsive Disorder

Inhibitory control is considered a compromised cognitive function in obsessive-compulsive (OCD) patients and likely linked to corticostriatal circuitry disturbances. Here, 9 refractory OCD patients treated with deep brain stimulation (DBS) were evaluated to address the dynamic modulations of large-scale cortical network activity involved in inhibitory control after nucleus accumbens (NAc) stimulation and their relationship with cortical thickness. A comparison of DBS "On/Off" states showed that patients committed fewer errors and exhibited increased intraindividual reaction time variability, resulting in improved goal maintenance abilities and proactive inhibitory control. Visual P3 event-related potentials showed increased amplitudes during Go/NoGo performance. Go and NoGo responses increased cortical activation mainly over the right inferior frontal gyrus and medial frontal gyrus, respectively. Moreover, increased cortical activation in these areas was equally associated with a higher cortical thickness within the prefrontal cortex. These results highlight the critical role of NAc DBS for preferentially modulating the neuronal activity underlying sustained speed responses and inhibitory control in OCD patients and show that it is triggered by reorganizing brain functions to the right prefrontal regions, which may depend on the underlying cortical thinning. Our findings provide updated structural and functional evidence that supports critical dopaminergic-mediated frontal-striatal network interactions in OCD.

Forgetting Unwanted Memories: Active Forgetting and Implications for the Development of Psychological Disorders

Intrusive memories are a common feature of many psychopathologies, and suppression-induced forgetting of unwanted memories appears as a critical ability to preserve mental health. In recent years, biological and cognitive studies converged in revealing that forgetting is due to active processes. Recent neurobiological studies provide evidence on the active role of main neurotransmitter systems in forgetting, suggesting that the brain actively works to suppress retrieval of unwanted memories. On the cognitive side, there is evidence that voluntary and involuntary processes (here termed "intentional" and "incidental" forgetting, respectively) contribute to active forgetting. In intentional forgetting, an inhibitory control mechanism suppresses awareness of unwanted memories at encoding or retrieval. In incidental forgetting, retrieval practice of some memories involuntarily suppresses the retrieval of other related memories. In this review we describe recent findings on deficits in active forgetting observed in psychopathologies, like post-traumatic stress disorder, depression, schizophrenia, and obsessive-compulsive disorder. Moreover, we report studies in which the role of neurotransmitter systems, known to be involved in the pathogenesis of mental disorders, has been investigated in active forgetting paradigms. The possibility that biological and cognitive mechanisms of active forgetting could be considered as hallmarks of the early onset of psychopathologies is also discussed.

Obsessive-Compulsive Disorder and Decision Making under Ambiguity: A Systematic Review with Meta-Analysis

In the last decade, decision-making has been proposed to have a central role in obsessive-compulsive disorder (OCD) aetiology, since patients show pathological doubt and an apparent inability to make decisions. Here, we aimed to comprehensively review decision making under ambiguity, as measured by the Iowa Gambling Task (IGT), in OCD, using a meta-analytic approach. According to PRISMA Guidelines, we selected 26 studies for a systematic review and, amongst them, 16 studies were included in a meta-analysis, comprising a total of 846 OCD patients and 763 healthy controls (HC). Our results show that OCD patients perform significantly lower than HC at the IGT, pointing towards the direction of a decision making impairment. In particular, this deficit seems to emerge mainly in the last three blocks of the IGT. IGT scores in OCD patients under the age of 18 were still significantly lower than in HC. Finally, no difference emerged between medicated and unmedicated patients, since they both scored significantly lower at the IGT compared to HC. In conclusion, our results are in line with the hypothesis according to which decision making impairment might represent a potential endophenotype lying between the clinical manifestation of OCD and its neurobiological aetiology.

The effects of selective serotonin reuptake inhibitors on brain functional networks during goal-directed planning in obsessive-compulsive disorder

Whether brain network connectivity during goal-directed planning in patients with obsessive–compulsive disorder (OCD) is abnormal and restored by treatment with selective serotonin reuptake inhibitors (SSRIs) remains unknown. This study investigated whether the disrupted network connectivity during the Tower of London (ToL) planning task in medication-free OCD patients could be restored by SSRI treatment. Seventeen medication-free OCD patients and 21 matched healthy controls (HCs) underwent functional magnetic resonance imaging (fMRI) while performing the ToL task at baseline and again after 16 weeks of SSRI treatment. Internetwork connectivity was compared across the groups and treatment statuses (pretreatment versus posttreatment). At baseline, compared with the HCs, the OCD patients showed lower internetwork connectivity between the dorsal attention network and the default-mode network during the ToL planning task. After 16 weeks of SSRI treatment, the OCD patients showed improved clinical symptoms accompanied by normalized network connectivity, although their improved behavioral performance in the ToL task did not reach that of the HCs. Our findings support the conceptualization of OCD as a network disease characterized by an imbalance between brain networks during goal-directed planning and suggest that internetwork connectivity may serve as an early biomarker of the effects of SSRIs on goal-directed planning.

Hippocampal functional network: The mediating role between obsession and anxiety in adult patients with obsessive-compulsive disorder

OBJECTIVES

Anxiety is a very common symptom and closely related to obsessive-compulsive symptoms in obsessive-compulsive disorder (OCD). However, the association between anxiety and obsessive-compulsive symptoms at the hippocampus network level remains unclear.

METHODS

This study enrolled 42 patients with OCD and 42 healthy controls (HCs), who underwent resting-state functional magnetic resonance imaging (fMRI) and clinical evaluation. Multiple linear regression analysis was performed to investigate the behavioural significance and interactive effects of obsessive-compulsive and anxiety symptoms on the hippocampus functional connectivity (HFC). The mediation analysis model was used to explore whether the hippocampus functional connectivity (FC) network indirectly mediated the relationship between obsessive-compulsive symptoms and anxiety.

RESULTS

Results showed that the FCs with the cerebellum, middle temporal gyrus (MTG) and anterior cingulate gyrus (ACG) were increased in the hippocampus FC network in patients with OCD compared with those in HCs. The regions of interactive effects between anxiety and obsession, which are mainly located in the prefrontal cortex and MTG, were positively correlated. The mediation effect is 0.018 between obsession and anxiety on the HFC networks in patients with OCD.

CONCLUSIONS

The FC between the hippocampus and MTG plays a key role in the relationship between anxiety and obsession.

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.

Projection-specific deficits in synaptic transmission in adult Sapap3-knockout mice

Obsessive-compulsive disorder (OCD) is a circuit disorder involving corticostriatal projections, which play a role in motor control. The Sapap3-knockout (KO) mouse is a mouse model to study OCD and recapitulates OCD-like compulsion through excessive grooming behavior, with skin lesions appearing at advanced age. Deficits in corticostriatal control provide a link to the pathophysiology of OCD. However, there remain significant gaps in the characterization of the Sapap3-KO mouse, with respect to age, specificity of synaptic dysfunction, and locomotor phenotype. We therefore investigated the corticostriatal synaptic phenotype of Sapap3-KO mice using patch-clamp slice electrophysiology, in adult mice and with projection specificity. We also analyzed grooming across age and locomotor phenotype with a novel, unsupervised machine learning technique (MoSeq). Increased grooming in Sapap3-KO mice without skin lesions was age independent. Synaptic deficits persisted in adulthood and involved the projections from the motor cortices and cingulate cortex to the dorsolateral and dorsomedial striatum. Decreased synaptic strength was evident at the input from the primary motor cortex by reduction in AMPA receptor function. Hypolocomotion, i.e., slowness of movement, was consistently observed in Sapap3-KO mice. Our findings emphasize the utility of young adult Sapap3-KO mice to investigate corticostriatal synaptic dysfunction in motor control.

Impairment in the goal-directed corticostriatal learning system as a biomarker for obsessive-compulsive disorder

BACKGROUND

Compulsive behaviors in obsessive-compulsive disorder (OCD) have been related to impairment within the associative cortical-striatal system connecting the caudate and prefrontal cortex that underlies consciously-controlled goal-directed learning and behavior. However, little is known whether this impairment may serve as a biomarker for vulnerability to OCD.

METHODS

Using resting-state functional magnetic resonance imaging (fMRI), we employed Granger causality analysis (GCA) to measure effective connectivity (EC) in previously validated striatal sub-regions, including the caudate, putamen, and the nucleus accumbens, in 35 OCD patients, 35 unaffected first-degree relatives and 35 matched healthy controls.

RESULTS

Both OCD patients and their first-degree relatives showed greater EC than controls between the left caudate and the orbital frontal cortex (OFC). Both OCD patients and their first-degree relatives showed lower EC than controls between the left caudate and lateral prefrontal cortex. These results are consistent with findings from task-related fMRI studies which found impairment in the goal-directed system in OCD patients.

CONCLUSIONS

The same changes in EC were present in both OCD patients and their unaffected first-degree relatives suggest that impairment in the goal-directed learning system may be a biomarker for OCD.

Loss in grey matter in a small network of brain areas underpins poor reactive inhibition in Obsessive-Compulsive Disorder patients

Reactive inhibition correlates with the severity of symptoms in paediatric patients with Obsessive-Compulsive Disorder (OCD) though not in those with Tourette syndrome (TS). Here we assessed whether structural alterations in both grey (GM) and white matter (WM) volumes correlate with a measure of reactive inhibition, i.e. the stop-signal reaction time (SSRT), and with clinical scale scores. Nine OCD and 11 TS uncomplicated drug-naïve paediatric patients and 12 age-matched controls underwent 3T magnetic resonance imaging scanning. Between-group differences in GM and WM volumes across the whole brain were assessed. Outside the scanner, patients performed a reaching version of the stop-signal task. Both behavioural inhibitory control and neuroimaging measures were normal in TS patients. By contrast, OCD patients exhibited a significant loss in GM volume in five areas. The GM volume of the left inferior frontal gyrus was inversely correlated with the length of the SSRT, the left mid-cingulate gyrus and the right middle frontal gyrus were inversely correlated with the severity of OCD symptoms, and the left insula and the right medial orbitofrontal gyrus were inversely correlated with both. These results indicate that cortical areas showing GM loss in OCD patients are also involved in the network subserving reactive inhibition.

Maintained Visual-, Auditory-, and Multisensory-Guided Associative Learning Functions in Children With Obsessive-Compulsive Disorder

Sensory-guided acquired equivalence learning, a specific kind of non-verbal associative learning, is associated with the frontal cortex-basal ganglia loops and hippocampi, which seem to be involved in the pathogenesis of obsessive-compulsive disorder (OCD). In this study, we asked whether visual-, auditory-, and multisensory-guided associative acquired equivalence learning is affected in children with OCD. The first part of the applied learning paradigm investigated association building between two different sensory stimuli (where feedback was given about the correctness of the choices), a task that critically depends upon the basal ganglia. During the test phases, which primarily depended upon the hippocampi, the earlier learned and hitherto not shown but predictable associations were asked about without feedback. This study involved 31 children diagnosed with OCD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-V) criteria and 31 matched healthy control participants. The children suffering from OCD had the same performance as the control children in all phases of the applied visual-, auditory-, and multisensory-guided associative learning paradigms. Thus, both the acquisition and test phases were not negatively affected by OCD. The reaction times did not differ between the two groups, and the applied medication had no effect on the performances of the OCD patients. Our results support the findings that the structural changes of basal ganglia and hippocampi detected in adult OCD patients are not as pronounced in children, which could be the explanation of the maintained associative equivalence learning functions in children suffering from OCD.

Differences between individuals with schizophrenia or obsessive-compulsive disorder and healthy controls in social cognition and mindfulness skills: A controlled study

The study of social cognition (SC) has emerged as a key domain of mental health, supporting the notion that poorer performance in SC tasks is linked to psychopathology, although most studies have primarily addressed only schizophrenia (SZ). Some recent studies have also shown deficits of SC in obsessive-compulsive disorder (OCD) patients; however, little is known about how individuals with OCD may differ on SC performance from individuals with SZ. Moreover, initial research in this field suggests that mindfulness skills may be related to SC abilities such as theory of mind (ToM), emotion processing and empathy. Given the potential benefits of mindfulness for treating OCD and SZ, further efforts are needed to understand the association between mindfulness and SC in these populations. The main objective of this study was to compare samples of patients with SZ and OCD to healthy controls (HCs) on several social cognition (SC) domains and mindfulness measures. In total, 30 outpatients diagnosed with SZ, 31 outpatients diagnosed with OCD and 30 healthy controls were assessed in emotion recognition (the Eyes Test), ToM (the Hinting Task), attributional style (the Ambiguous Intentions and Hostility Questionnaire), empathy (the Interpersonal Reactivity Index) and dispositional mindfulness (the MAAS and the FFMQ). Both clinical groups showed poorer performance in emotion recognition and ToM than the HCs. The OCD and SZ patients did not significantly differ in impairment in SC, but the OCD group had higher scores in attributional style (intentionality and anger bias). With regard to mindfulness, the results found lower levels of acting with awareness for the HCs than for either clinical group and higher non-reactivity to inner experience for the HCs than for the individuals with OCD; the results also yielded significant correlations between SC and mindfulness. In conclusion, these findings revealed that SC abilities were impaired in the SZ and OCD groups compared to the HC group, suggesting a similar disrupted pattern in both clinical groups. Aspects of dispositional mindfulness were differentially associated with SC, which may suggest their potential role in novel transdiagnostic interventions.

Obsessive-Compulsive Disorder

PURPOSE OF REVIEW

This article reviews current knowledge regarding diagnosis, pathophysiology, and treatment trends in obsessive-compulsive disorder (OCD), a severe, underrecognized, and chronic condition frequently encountered in neurologic practice.

RECENT FINDINGS

With a lifetime prevalence estimated at 2.5%, OCD is a common condition that can also present comorbidly with neurologic disease. The core symptoms of OCD are obsessions and compulsions. Obsessions are intrusive repetitive thoughts, urges, images, or impulses that trigger anxiety and that the individual is not able to suppress. Compulsions are repetitive behaviors or mental acts occurring in response to an obsession with the intention of reducing the distress caused by obsessions. Neuroimaging, neuropsychological, and pharmacologic studies suggest that the expression of OCD symptoms is associated with dysfunction in a cortico-striato-thalamo-cortical circuit. Evidence-based treatments for OCD comprise pharmacotherapy and cognitive-behavioral therapy. Selective serotonin reuptake inhibitors (SSRIs) are the first-line drugs recommended for OCD, but significant differences exist in their use for OCD compared to their use for other mood and anxiety conditions, including the need for higher dosage, longer trials necessitated by a longer lag for therapeutic response, and typically lower response rates. Cognitive-behavioral therapy, based on the principles of exposure and response prevention, shows results superior to pharmacologic treatments with lower relapse rates on long-term follow-up and thus should be considered in the treatment plan of every patient with OCD.

SUMMARY

OCD and obsessive-compulsive symptoms are frequently encountered in the neurologic clinic setting and require a high index of suspicion to effectively screen for them and an illness-specific therapeutic approach.

Obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a highly prevalent and chronic condition that is associated with substantial global disability. OCD is the key example of the 'obsessive-compulsive and related disorders', a group of conditions which are now classified together in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and the International Classification of Diseases, 11th Revision, and which are often underdiagnosed and undertreated. In addition, OCD is an important example of a neuropsychiatric disorder in which rigorous research on phenomenology, psychobiology, pharmacotherapy and psychotherapy has contributed to better recognition, assessment and outcomes. Although OCD is a relatively homogenous disorder with similar symptom dimensions globally, individualized assessment of symptoms, the degree of insight, and the extent of comorbidity is needed. Several neurobiological mechanisms underlying OCD have been identified, including specific brain circuits that underpin OCD. In addition, laboratory models have demonstrated how cellular and molecular dysfunction underpins repetitive stereotyped behaviours, and the genetic architecture of OCD is increasingly understood. Effective treatments for OCD include serotonin reuptake inhibitors and cognitive-behavioural therapy, and neurosurgery for those with intractable symptoms. Integration of global mental health and translational neuroscience approaches could further advance knowledge on OCD and improve clinical outcomes.

Altered resting-state cerebellar-cerebral functional connectivity in obsessive-compulsive disorder

BACKGROUND

The role of the cerebellum in obsessive-compulsive disorder (OCD) has drawn increasing attention. However, the functional connectivity between the cerebellum and the cerebral cortex has not been investigated in OCD, nor has the relationship between such functional connectivity and clinical symptoms.

METHODS

A total of 27 patients with OCD and 21 healthy controls (HCs) matched on age, sex and education underwent magnetic resonance imaging (MRI). Seed-based connectivity analyses were performed to examine differences in cerebellar-cerebral connectivity in patients with OCD compared with HCs. Associations between functional connectivity and clinical features in OCD were analyzed.

RESULTS

Compared with HCs, OCD patients showed significantly decreased cerebellar-cerebral functional connectivity in executive control and emotion processing networks. Within the OCD group, decreased functional connectivity in an executive network spanning the right cerebellar Crus I and the inferior parietal lobule was positively correlated with symptom severity, and decreased connectivity in an emotion processing network spanning the left cerebellar lobule VI and the lingual gyrus was negatively correlated with illness duration.

CONCLUSIONS

Altered functional connectivity between the cerebellum and cerebral networks involved in cognitive-affective processing in patients with OCD provides further evidence for the involvement of the cerebellum in the pathophysiology of OCD, and is consistent with impairment in executive control and emotion regulation in this condition.

Behavioral flexibility in a mouse model for obsessive-compulsive disorder: Impaired Pavlovian reversal learning in SAPAP3 mutants

Obsessive-compulsive disorder (OCD) is characterized by obsessive thinking, compulsive behavior and anxiety, and is often accompanied by cognitive deficits. The neuropathology of OCD involves dysregulation of cortical-striatal circuits. Similar to OCD patients, SAPAP3 knockout mice 3 (SAPAP3-/- ) exhibit compulsive behavior (grooming), anxiety and dysregulated cortical-striatal function. However, it is unknown whether SAPAP3-/- display cognitive deficits and how these different behavioral traits relate to one another. SAPAP3-/- and wild-type (WT) littermates were trained in a Pavlovian conditioning task pairing visual cues with the delivery of sucrose solution. After mice learned to discriminate between a reward-predicting conditioned stimulus (CS+) and a non-reward stimulus (CS-), contingencies were reversed (CS+ became CS- and vice versa). Additionally, we assessed grooming, anxiety and general activity. SAPAP3-/- acquired Pavlovian approach behavior similarly to WT, albeit less vigorously and with a different strategy. However, unlike WT, SAPAP3-/- were unable to adapt their behavior after contingency reversal, exemplified by a lack of re-establishing CS+ approach behavior (sign tracking). Surprisingly, such behavioral inflexibility, decreased vigor, compulsive grooming and anxiety were unrelated. This study shows that SAPAP3-/- are capable of Pavlovian learning, but lack flexibility to adapt associated conditioned approach behavior. Thus, SAPAP3-/- not only display compulsive-like behavior and anxiety, but also cognitive deficits, confirming and extending the validity of SAPAP3-/- as a suitable model for the study of OCD. The observation that compulsive-like behavior, anxiety and behavioral inflexibility were unrelated suggests a non-causal relationship between these traits and may be of clinical relevance for the treatment of OCD.

Combined fluvoxamine and extended-release methylphenidate improved treatment response compared to fluvoxamine alone in patients with treatment-refractory obsessive-compulsive disorder: A randomized double-blind, placebo-controlled study

More effective, tolerable interventions for treatment-refractory obsessive-compulsive disorder (OCD) are needed. Preliminary findings encourage optimism that methylphenidate augmentation may be of benefit in the treatment of OCD. To test modulator methylphenidate (MPH) of extended-release formulations (MPH-ER) a safe and effective add-on therapy for refractory OCD, a pilot randomized, placebo-controlled, double-blind trial was conducted at an outpatient, single-center academic setting. Participants included 44 adults with serotonin reuptake inhibitor (SRI) treatment-refractory OCD and receiving a stable fluvoxamine pharmacotherapy with Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scores higher than 20. Data were analyzed in the intention-to-treat sample. All subjects were randomized into two parallel groups to receive fluvoxamine (250 mg daily) plus MPH-ER (36 mg daily) or fluvoxamine (250 mg daily) plus identical placebo tablets under double-blind conditions and followed for 8 weeks. Forty-four patients (29 [66%] men), with a mean (SD) age of 24.7 (6) years participated; with a mean (SD) duration of episode 5.7 (3) were randomized and forty-one finished the trial. In the intention-to-treat analysis, the improvement in the Y-BOCS total score and Y-BOCS obsession subscale score was more prominent in the fluvoxamine and MPH-ER group compared with those receiving placebo (P < .001). Additionally, cumulative response rates were higher in the MPH-ER vs placebo groups (59% vs 5%; P  < .001). MPH-ER was well tolerated; No subjects dropped out due to side effects. In summary, combined treatment with MPH-ER demonstrated an enhanced clinical rate of response compared to placebo. Further trials should examine MPH-ER efficacy in a larger sample.

Cognitive Process in Patients With Obsessive-Compulsive Disorder: A Cross-Sectional Analytic Study

Introduction:

In recent studies, deficit in cognitive process has been investigated as one of the etiological hypotheses in a wide range of Obsessive-Compulsive Disorder (OCD). This research aimed to compare cognitive process in patients with OCD and healthy groups.

Methods:

In the current cross-sectional analytic study, 43 patients with OCD and 43 healthy individuals matched with gender, age, educational and marital status were selected by convenience sampling method and assessed by Wisconsin Cart Sorting Test (WCST), Paced Auditory Serial Addition Test (PASAT) and Yale-Brown Obsessive Compulsive Scale (Y-BOCS). The obtained data were analyzed with Chi-square, Independent t test, Mann-Whitney U test and Pearson correlation in SPSS version16.

Results:

There was no difference between the patients with OCD and the healthy group in demographic characteristics (P>0.05). There was a significant differences between two group on the all subscale of WCST test and PASAT3, PASAT2 tests (P<0.01). These findings indicate that the OCD patient’s performance in cognitive process was significantly worse than the healthy controls.

Conclusion:

The findings indicate that individuals with OCD suffer from a deficiency in various aspects of cognitive processes. Therefore, paying attention to these deficiencies can make an important contribution to the treatment of these patients.

Blood levels of interleukin-1 beta, interleukin-6 and tumor necrosis factor-alpha and cognitive functions in patients with obsessive compulsive disorder

BACKGROUND

Cognitive dysfunction and immune system disorders are two actual issues for the patients with Obsessive Compulsive Disorder (OCD). The cognitive dysfunctions have been considered to substantial part of clinical phenomenon of OCD but exploration of various etiopathogenesis of cognitive dysfunction is needed. Immune dysfuncion has been implicated to be important part of pathopysiology of OCD and different lines of evidence suggests immune abnormalities in OCD. But whether these immune changes are traits of disease or secondary to clinical burden of the disease such as cognitive dysfunctions has not been determined. Data regarding relation between the cognitive dysfunctions and immune system disorders in OCD is unsatisfied. In this study we aimed to investigate the relation of blood levels of interleukin 1-beta (IL-1ß), interleukin-6 (IL-6) and Tumor Necrosis Factor-α (TNF-α) with various neurocognitive functions in patients with OCD in comparison with its autogenous/reactive subtypes and healthy controls. Further exploration of the effects of various clinical variables on cognitive functioning in patients with OCD and additional investigation of whether the cognitive dysfunction associated with this disorder differs from or overlap with that in other anxiety disorders are needed.

METHODS

Forty-two patient with OCD and 45 age, sex and educational level matched healthy control were enrolled in the study. The diagnosis of OCD was made with Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Yale- Brown Obsessive-Compulsive Scale, Beck Anxiety and Depression Inventory Scales were administered. Neuropsychological test battery including Wisconsin Card Sorting Test (WCST), Trail Making Test A and B (TMT-A, TMT-B) were used for evaluation of the patients and healthy control. The plasma of interleukin-1beta (IL-1ß), interleukin-6 (IL-6), Tumor Necrosis Factor-Alpha (TNF-α) of both groups were measured with ELISA kits.

RESULTS

Blood levels of IL-1ß, IL-6 and TNF-α were significantly higher in patients with OCD than the healthy control. There was significant difference in IL-1ß, IL-6 but not in TNF-α between autogenous/reactive subtypes and healthy controls. TNF-α is positively correlated with TMT-A, TMT-B and Stroop Test Part 5, negatively correlated with immediate memory, verbal learning, interference effect, immediate recall, delayed recall and recognition in RAVLT. IL-1ß was positively correlated with TMT-A score. IL-6 was positively correlated with scores of TMT-A, TMT-B. IL-6 was negatively correlated with immediate memory, verbal learning, interference effect, immediate recall and delayed recall in RAVLT, positively correlated with number of perseverative error and negatively correlated with the number of categories completed in WCST.

CONCLUSION

This is the first study that investigates the relation of IL- 1ß, IL-6 and TNF-α levels with cognitive functions in OCD. There may be a contribution to pathogenesis of OCD and subtypes then new choices for treatment might be developed. Moreover, uncovering the effect of cytokine blood levels on cognitive function of OCD, new data concerning etiopathogenesis and further treatment choices can be gained.

Altered Functional Connectivity Between the Cerebellum and the Cortico-Striato-Thalamo-Cortical Circuit in Obsessive-Compulsive Disorder

Background: Altered resting-state functional connectivity of the cerebellum in obsessive-compulsive disorder (OCD) has been previously reported. However, the previous study investigating cerebellar-cerebral functional connectivity relied on a priori-defined seeds from specific networks. In this study, we aimed to explore the connectivity alterations of the cerebellum in OCD under resting-state conditions with a hypothesis-free approach. Methods: Thirty patients with OCD and 26 healthy controls (HCs) underwent functional magnetic resonance imaging (fMRI) scanning at resting state. Regional cerebral function was evaluated by measuring the fraction of amplitude of low-frequency fluctuation (fALFF). Regions with mean fALFF (mfALFF) alterations were used as seeds in seed correlation analysis (SCA). An independent samples t test was used to compare the differences in mfALFF and functional connection (FC) between the two groups. Pearson correlation analysis was performed to identify the association between functional neural correlates and OCD symptom severity evaluated using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Results: Compared with the HC group, the OCD group showed significantly increased mfALFF values in bilateral cerebellar. The results of FC analysis showed weakened connectivity among the left Crus II, lobule VIII, and right striatum and between the right lobule VIII and the right striatum, and cingulate in the OCD group compared with the HC group. Some of the abovementioned results were associated with symptom severity. Conclusions: OCD patients showed abnormal spontaneous cerebellar activity and weakened functional connectivity between the cerebellum and the cortico-striato-thalamo-cortical (CSTC) circuit (striatum and cingulate), suggesting that the cerebellum may play an essential role in the pathophysiology of OCD.

The Relationship Between Obsessive Belief Level and Cognitive Flexibility in Patients with Obsessive Compulsive Disorder

Introduction

It is known that dysfunctional beliefs are important in the onset and maintenance of symptoms of Obsessive Compulsive Disorder (OCD) according to the cognitive model of OCD. OCD patients with higher obsessive beliefs would be expected to have greater deficits in cognitive flexibility. In this study, we aimed to examine the relationship between obsessive belief levels and cognitive flexibility in OCD patients.

Methods

Patients with OCD (50) and Panic Disorder (30) as a control group were evaluated and diagnosed using Structured Clinical Interview for DSM-IV Axis I Disorders. A socio-demographic data form, Beck Depression Inventory, Beck Anxiety Inventory and Wisconsin Card Sorting Test (WCST) were administered to all the patients. The Yale-Brown Obsessive Compulsive Scale and Obsessive Beliefs Questionnaire-44 (OBQ-44) were administered to the OCD group. The OCD group was divided into two subgroups as higher obsessive beliefs (OCD-H) (n=29) and lower obsessive beliefs (OCD-L) (n=21) according to a cluster analytic approach.

Results

When the subgroups were compared according to WCST; the number of completed categories was statistically significantly lower, and the numbers of total errors, perseverative errors and non-perseverative errors were significantly higher in the OCD-H group.

Conclusion

The results of our study show that cognitive flexibility is impaired in OCD patients with higher obsessive beliefs.

Differential pattern of brain functional connectome in obsessive-compulsive disorder versus healthy controls

Researchers believe that recognition of functional impairment in some of brain networks such as frontal-parietal, default mode network (DMN), anterior medial prefrontal cortex (MPFC) and striatal structures could be a beneficial biomarker for diagnosis of obsessive-compulsive disorder (OCD). Although it is well recognized brain functional connectome in OCD patients shows changes, debate still remains on characteristics of the changes. In this regard, little has been done so far to statistically assess the altered pattern using whole brain electroencephalography. In this study, resting state EEG data of 39 outpatients with OCD and 19 healthy controls (HC) were recorded. After, brain functional network was estimated from the cleaned EEG data using the weighted phase lag index algorithm. Output matrices of OCD group and HCs were then statistically compared to represent meaningful differences. Significant differences in functional connectivity pattern were demonstrated in several regions. As expected the most significant changes were observed in frontal cortex, more significant in frontal-temporal connections (between F3 and F7, and T5 regions). These results in OCD patients are consistent with previous studies and confirm the role of frontal and temporal brain regions in OCD.

Executive functions, selective attention and information processing in patients with obsessive compulsive disorder: A study from west of Iran

Obsessive-compulsive disorder (OCD) is associated with cognitive dysfunction. Deeper and wider knowledge of the cognitive components of these patients can play an important role in better understanding of this disorder. This study aimed to compare executive function, selective attention and information processing in OCD patients and healthy controls. The current study was performed on 54 patients meeting DSM-5 criteria for OCD and 54 healthy subjects who matched with patients in gender, age, marital and educational status. The cognitive functions were assessed by The Stroop test, Wisconsin Cart Sorting Test (WCST), Paced Auditory Serial Addition Test (PASAT) and the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). The performance of the OCD group was significantly worse than the healthy group in comparison with the all subscales of the Stroop and WSCT tests. Also, functions in information processing among two groups were statistically significant for 3- and 2-second PASAT. The results demonstrated that OCD patients have deficits in several aspects of cognitive functions. Hence, the treatment of these patients can be contributed by paying more attention to these deficits.

Central serotonin modulates neural responses to virtual violent actions in emotion regulation networks

Disruptions in the cortico-limbic emotion regulation networks have been linked to depression, anxiety, impulsivity, and aggression. Altered transmission of the central nervous serotonin (5-HT) contributes to dysfunctions in the cognitive control of emotions. To date, studies relating to pharmaco-fMRI challenging of the 5-HT system have focused on emotion processing for facial expressions. We investigated effects of a single-dose selective 5-HT reuptake inhibitor (escitalopram) on emotion regulation during virtual violence. For this purpose, 38 male participants played a violent video game during fMRI scanning. The SSRI reduced neural responses to violent actions in right-hemispheric inferior frontal gyrus and medial prefrontal cortex encompassing the anterior cingulate cortex (ACC), but not to non-violent actions. Within the ACC, the drug effect differentiated areas with high inhibitory 5-HT1A receptor density (subgenual s25) from those with a lower density (pregenual p32, p24). This finding links functional responses during virtual violent actions with 5-HT neurotransmission in emotion regulation networks, underpinning the ecological validity of the 5-HT model in aggressive behavior. Available 5-HT receptor density data suggest that this SSRI effect is only observable when inhibitory and excitatory 5-HT receptors are balanced. The observed early functional changes may impact patient groups receiving SSRI treatment.

Planning functioning and impulsiveness in obsessive-compulsive disorder

Planning ability (PA) is a key aspect of cognitive functioning and requires subjects to identify and organise the necessary steps to achieve a goal. Despite the central role of executive dysfunction in patients with obsessive-compulsive disorder (OCD), deficits in PA have been investigated leading to contrasting results. Given these inconsistencies, the main aim of our work is to give a deeper and clearer understanding of PA in OCD patients. Moreover, we are interested in investigating the relationship between PAs and impulsivity traits and other clinical variables. Sixty-eight OCD patients and 68 healthy controls (HCs) matched for sex and age were assessed through the Stocking of Cambridge (SoC), a computerised version of the Tower of London. We examined planning sub-components for each difficulty levels (from 2 to 5 minimum moves). Our results showed that OCD patients needed longer initial thinking time than HCs during the execution of low demanding tasks (i.e. 2 and 3 moves), while the accuracy level between the two groups did not significantly differ. OCD patients required longer initial thinking time also during high demanding tasks (i.e., 4 and 5 moves), but in this case their accuracy was significantly worse than HCs' one. We did not find any association between impulsivity and PAs. Our results supported the hypothesis that OCD patients were not able to retain in memory the planned sequence and they had to reschedule their movements during the execution. Thus, future studies should deepen the interrelation between working memory and PA to better understand the influence between these two cognitive functions and their interaction with clinical variables in OCD patients.

Dysfunction by Disclosure? Stereotype Threat as a Source of Secondary Neurocognitive Malperformance in Obsessive-Compulsive Disorder

OBJECTIVES

There is mixed evidence regarding whether patients with obsessive-compulsive disorder (OCD) display substantial neurocognitive deficits. Several studies implicate poor motivation, comorbid disorders, or distraction due to obsessive thoughts as potential causes of secondary malperformance. The present study examined the impact of stereotype threat (i.e., confrontation with a negative stereotype may impair performance) on neuropsychological functioning in individuals with OCD. We hypothesized that a stereotype threat cue emphasizing neurocognitive deficits in OCD (as is often conveyed in disclosure and consent documents that inform patients about the purpose of a study) would compromise patients' test performance relative to a control group who did not receive such cue.

METHODS

Fifty participants with either a verified or a likely diagnosis of OCD were recruited online and randomly assigned to either an experimental condition aimed to elicit stereotype threat or a control condition. Both groups underwent (objective) memory and attention (Go/NoGo task) assessments and completed questionnaires capturing psychopathology, cognitive complaints, and self-stigma.

RESULTS

As hypothesized, patients in the stereotype threat condition performed worse on the Go/NoGo task. Groups did not differ on any other measures.

CONCLUSIONS

Stereotype threat negatively impacted neuropsychological performance on an attention task. The threat cue was perhaps too weak or the stereotype threat was already internalized by the patients and "saturated" at baseline so that no effect emerged on the other measures. Implications for clinical trials are discussed. (JINS, 2018, 24, 584-592).

Decreased memory confidence in obsessive-compulsive disorder for scenarios high and low on responsibility: is low still too high?

Previous research suggests that patients with obsessive-compulsive disorder (OCD), particularly checkers, display an inflated sense of responsibility. For the present study, we tested whether memory confidence in OCD is reduced under conditions of heightened responsibility and/or reflects poor memory vividness. A computerized task designed to modulate perceived responsibility was administered to 26 OCD patients (12 checkers) and 21 healthy controls. In the experimental condition (high responsibility), participants had to allocate daily medications to ten fictive patients in a hospital emergency ward, whereas in the control condition (low responsibility) participants had to allocate bath essences for ten hotel guests. Participants' response time and accuracy were recorded as well as their memory confidence, memory vividness, and subjective success. Irrespective of the condition, OCD patients performed as accurately as healthy controls, but appraised their performance as worse than that of controls. Memory confidence was decreased in patients, particularly checkers. No group differences emerged on vividness, and none of the effects were moderated by the condition (high versus low responsibility). The relationship between responsibility and OCD behavior is complex. Results suggest metamemory problems in OCD checkers, even when induced responsibility is low. The findings speak against "cold" memory deficits in OCD, as patients did not differ from controls on accuracy, reaction time, or vividness. Future research should focus on idiosyncratic beliefs and scenarios that inflate responsibility and elicit cognitive biases.