Neuropsychological functioning in a subclinical obsessive-compulsive sample

Long-term remission rates and trajectory predictors in obsessive-compulsive disorder: Findings from a six-year naturalistic longitudinal cohort study

BACKGROUND

This naturalistic study, utilizing data from the Netherlands Obsessive-Compulsive Disorder Association (NOCDA) cohort, investigated the long-term remission rates and predictors of different trajectories of obsessive-compulsive disorder (OCD) within a clinical population.

METHODS

A sample of 213 participants was classified into three illness trajectories: "Chronic," "Episodic, "and "Remitted-OCD." Long-term remission rates were calculated based on three follow-up measurements over a 6-year period. A multinomial logistic regression model, incorporating five selected predictors with high explanatory power and one covariate, was employed to analyze OCD trajectory outcomes.

RESULTS

The long-term full remission rates, calculated from all the measurements combined (14%), were significantly lower than what was observed in earlier studies and when compared to assessments at each individual follow-up (∼30%). Moreover, high baseline symptom severity and early age of onset were identified as significant risk factors for a chronic course of OCD, while male sex and younger age predicted a more favorable trajectory. Notably, the likelihood of an episodic course remained high even without identified risk factors.

LIMITATIONS

The bi-annual data collection process is unable to capture participants' clinical conditions between assessments. Additionally, no data was collected regarding the specific type and duration of psychological treatment received. Regarding the type of treatment participants received.

CONCLUSIONS

Results suggest that long-term remission rates may be lower than previously reported. Consequently, employing multiple assessment points in longitudinal studies is necessary for valid estimation of long-term full remission rates. The results emphasize the importance of personalized clinical care and ongoing monitoring and maintenance for most OCD cases.

Contamination-Focussed Vignettes as an Analogue of Infectious Pandemics: An Experimental Validation using the State Disgust and Anxiety Responses in OCD

Despite infectious pandemics proving particularly detrimental to those with Obsessive-Compulsive Disorder (OCD), the investigation of analogous experimental paradigms is lacking. To address this gap, we conducted two studies employing vignettes that depicted contamination-related situations commonly experienced during a pandemic (e.g., Coughing into hands and failing to use hand sanitizer). We manipulated the salience of these vignettes across three levels: high contamination, low contamination, and a neutral control condition. Our examination of state anxiety and disgust responses in all participants revealed the successful manipulation of the vignettes' impact. Specifically, individuals with more severe OCD symptoms reported significantly higher levels of state disgust and anxiety for both high and low contamination vignettes, in contrast to the group with lower symptom severity. No significant differences were observed in the neutral vignette condition between the high- and low-scoring groups. Interestingly, for those with higher OCD symptoms, high salience contamination-focused vignettes resulted in similarly elevated state disgust and anxiety, regardless of whether the vignettes were situated in public (Study 1) or domestic (Study 2) settings. This suggests that the heightened sensitivity to contamination-related scenarios observed in individuals with OCD symptoms in the present study is not confined to a specific context. These findings support the use of contamination-focused vignettes as analogues for studying infectious pandemics and provide valuable insights into OCD models, interventions, and future research.

Disruption of consciousness depends on insight in OCD and on positive symptoms in schizophrenia

Disruption of conscious access contributes to the advent of psychotic symptoms in schizophrenia but could also explain lack of insight in other psychiatric disorders. In this study, we explored how insight and psychotic symptoms related to disruption of consciousness. We explored consciousness in patients with schizophrenia, patients with obsessive-compulsive disorder (OCD) with good vs. poor insight and matched controls. Participants underwent clinical assessments and performed a visual masking task allowing us to measure individual consciousness threshold. We used a principal component analysis to reduce symptom dimensionality and explored how consciousness measures related to symptomatology. We found that clinical dimensions could be well summarized by a restricted set of principal components which also correlated with the extent of consciousness disruption. More specifically, positive symptoms were associated with impaired conscious access in patients with schizophrenia whereas the level of insight delineated two subtypes of OCD patients, those with poor insight who had consciousness impairments similar to patients with schizophrenia, and those with good insight who resemble healthy controls. Our study provides new insights about consciousness disruption in psychiatric disorders, showing that it relates to positive symptoms in schizophrenia and with insight in OCD. In OCD, it revealed a distinct subgroup sharing neuropathological features with schizophrenia. Our findings refine the mapping between symptoms and cognition, paving the way for a better treatment selection.

Validation of the Russianversion of the Maudsley Obsessive-Compulsive Inventory (MOCI) in Population and Clinical Samples

Relevance. Obsessive-compulsive disorder (OCD) is the third most common psychiatric disorder, potentially disabling with significant social and economic consequences. In Russia, little attention is paid to the study of OCD, which leads to the problem of differential diagnosis and effective treatment of OCD. One of the reasons for the insufficient attention to OCD is the lack of validated Russian questionnaires for diagnosing OCD. The purpose of this work is the initial validation of a translated version of the Maudsley Obsessive-Compulsive Inventory (MOCI). Characteristics of the surveyed groups. A population-based sample of 300 students (212 women and 88 men) and a clinical sample of 13 patients with anxiety and depressive disorders (8 women and 5 men) and 13 patients with OCD (11 women and 2 men) participated in the study. Severity of OCD symptoms were assessed with the translated version of Maudsley questionnaire. Results. According to our data, the MOCI questionnaire allows to differentiate reliably (p = 0,027) patients with OCD from patients with anxiety-depressive disorders and can be suitable as a primary diagnostic test for identifying OCD patients (p < 0,05) and the risk group. The reliability and convergent validity of the questionnaire were shown.

The Relationship Between Compulsive Buying and Hoarding in China: A Multicenter Study

There is no previous research that has explored the correlation between compulsive buying and hoarding in the Chinese population. This study aims to determine the relationship between compulsive buying and hoarding in a sample of the Chinese population comprising participants from mainland China (emerging economy) and Hong Kong (developed economy). Self-reported measures consisting of demographic questions, the Chinese version of the Hoarding Rating Scale (CHRS), and Richmond Compulsive Buying Scale-Traditional Chinese (RCBS-TC) were administered to participants. After data collection, common method biases were precluded. The RCBS-TC and CHRS were validated by confirmatory factor analysis and found correlated by Pearson correlation coefficient. The RCBS-TC and CHRS demonstrated satisfactory levels of internal consistency (Cronbach’s α = 0.872 and 0.828, respectively). A three-factor model, including hoarding, obsessive-compulsive, and impulse control disorders, was obtained through Confirmatory Factor Analysis (CFA) with the satisfactory fit for the total sample from Hong Kong and mainland China. A significant correlation was found between RCBS-TC and CHRS (r = 0.473). Findings also showed that 14% of the participants exhibited compulsive buying behavior. This study provides sufficient proof of the reliability and validity of RCBS-TC and CHRS. Their relationship was explored based on two sets of samples from different regions in Asia, which contributes more applicability in a cross-cultural context.

Semantic Linkages of Obsessions From an International Obsessive-Compulsive Disorder Mobile App Data Set: Big Data Analytics Study

BACKGROUND

Obsessive-compulsive disorder (OCD) is characterized by recurrent intrusive thoughts, urges, or images (obsessions) and repetitive physical or mental behaviors (compulsions). Previous factor analytic and clustering studies suggest the presence of three or four subtypes of OCD symptoms. However, these studies have relied on predefined symptom checklists, which are limited in breadth and may be biased toward researchers' previous conceptualizations of OCD.

OBJECTIVE

In this study, we examine a large data set of freely reported obsession symptoms obtained from an OCD mobile app as an alternative to uncovering potential OCD subtypes. From this, we examine data-driven clusters of obsessions based on their latent semantic relationships in the English language using word embeddings.

METHODS

We extracted free-text entry words describing obsessions in a large sample of users of a mobile app, NOCD. Semantic vector space modeling was applied using the Global Vectors for Word Representation algorithm. A domain-specific extension, Mittens, was also applied to enhance the corpus with OCD-specific words. The resulting representations provided linear substructures of the word vector in a 100-dimensional space. We applied principal component analysis to the 100-dimensional vector representation of the most frequent words, followed by k-means clustering to obtain clusters of related words.

RESULTS

We obtained 7001 unique words representing obsessions from 25,369 individuals. Heuristics for determining the optimal number of clusters pointed to a three-cluster solution for grouping subtypes of OCD. The first had themes relating to relationship and just-right; the second had themes relating to doubt and checking; and the third had themes relating to contamination, somatic, physical harm, and sexual harm. All three clusters showed close semantic relationships with each other in the central area of convergence, with themes relating to harm. An equal-sized split-sample analysis across individuals and a split-sample analysis over time both showed overall stable cluster solutions. Words in the third cluster were the most frequently occurring words, followed by words in the first cluster.

CONCLUSIONS

The clustering of naturally acquired obsessional words resulted in three major groupings of semantic themes, which partially overlapped with predefined checklists from previous studies. Furthermore, the closeness of the overall embedded relationships across clusters and their central convergence on harm suggests that, at least at the level of self-reported obsessional thoughts, most obsessions have close semantic relationships. Harm to self or others may be an underlying organizing theme across many obsessions. Notably, relationship-themed words, not previously included in factor-analytic studies, clustered with just-right words. These novel insights have potential implications for understanding how an apparent multitude of obsessional symptoms are connected by underlying themes. This observation could aid exposure-based treatment approaches and could be used as a conceptual framework for future research.

Obsessive-Compulsive Symptoms Among Children in the Adolescent Brain and Cognitive Development Study: Clinical, Cognitive, and Brain Connectivity Correlates

BACKGROUND

Childhood obsessive-compulsive symptoms (OCSs) are common and can be an early risk marker for obsessive-compulsive disorder. The Adolescent Brain and Cognitive Development (ABCD) Study provides a unique opportunity to characterize OCSs in a large normative sample of school-age children and to explore corticostriatal and task-control circuits implicated in pediatric obsessive-compulsive disorder.

METHODS

The ABCD Study acquired data from 9- and 10-year-olds (N = 11,876). Linear mixed-effects models probed associations between OCSs (Child Behavior Checklist) and cognition (NIH Toolbox), brain structure (subcortical volume, cortical thickness), white matter (diffusion tensor imaging), and resting-state functional connectivity.

RESULTS

OCS scores showed good psychometric properties and high prevalence, and they were related to familial/parental factors, including family conflict. Higher OCS scores related to better cognitive performance (β = .06, t9966.60 = 6.28, p < .001, ηp2= .01), particularly verbal, when controlling for attention-deficit/hyperactivity disorder, which related to worse performance. OCSs did not significantly relate to brain structure but did relate to lower superior corticostriatal tract fractional anisotropy (β = -.03, t = -3.07, p = .002, ηp2= .02). Higher OCS scores were related to altered functional connectivity, including weaker connectivity within the dorsal attention network (β = -.04, t7262.87 = -3.71, p < .001, ηp2= .002) and weaker dorsal attention-default mode anticorrelation (β = .04, t7251.95 = 3.94, p < .001, ηp2 = .002). Dorsal attention-default mode connectivity predicted OCS scores at 1 year (β = -.04, t2407.61 = -2.23, p = .03, ηp2 = .03).

CONCLUSIONS

OCSs are common and may persist throughout childhood. Corticostriatal connectivity and attention network connectivity are likely mechanisms in the subclinical-to-clinical spectrum of OCSs. Understanding correlates and mechanisms of OCSs may elucidate their role in childhood psychiatric risk and suggest potential utility of neuroimaging, e.g., dorsal attention-default mode connectivity, for identifying children at increased risk for obsessive-compulsive disorder.

Validation and Measurement Invariance of the Leuven Obsessional Intrusions Inventory in Two Different Cultures

Obsessions - recurrent unwanted intrusive thoughts - are one of the two pillars of the Obsessive Compulsive Disorder (OCD). Although OCD has been reported across many different cultures, research on these cultural variations is hampered by the lack of cross-culturally sound instruments to assess intrusive thoughts. The aim of the current study is to investigate the psychometric properties of the recently developed Leuven Obsessional Intrusions Instrument (LOII) in two different cultural contexts. Turkish (N = 663) and Belgian (N = 496) participants were sampled from non-clinical student populations. Results from confirmatory factor analyses yielded a shortened version of the LOII (i.e., LOII-R) with a four-factor solution - aggressive, sexual, and contamination intrusions, and 'just-right' doubts - as the best fitting model across both cultures. The model met most criteria for strong measurement invariance, and proved to be both valid and reliable. The results of this study suggest that the LOII-R is a good candidate for cross-cultural studies on obsessional intrusions.

A call for prevention and early intervention in obsessive-compulsive disorder

BACKGROUND

Evidence suggests that many people with obsessive-compulsive disorder (OCD) have subclinical symptoms years before the development of their disorder and that early treatment may reduce its severity.

AIM

To explore prevention and early intervention strategies for OCD.

METHODS

A narrative literature review was conducted.

RESULTS

The literature in relation to the prevention of OCD is sparse. Genetic and environmental factors appear to be relevant to the aetiology of OCD, for example, the observation that hoarding symptoms and contamination/cleaning symptoms are more likely to also be present in first-degree relatives. Psychoeducation and the reduction of family accommodation, that is the act of parents, siblings or partners accommodating to the high-risk individual's requests to comply with their compulsions, are promising areas for prevention and early intervention in high-risk groups. Tertiary prevention has also been limited by an inadequate number of trained clinicians to deliver evidence-based treatments.

CONCLUSIONS

Much more research is needed in relation to the prevention of OCD. There is limited scope for primary prevention with respect to biological aetiological factors, but there is potential for strategies addressing environmental factors (eg, family factors). The effectiveness of psychoeducation for parents with OCD as a primary prevention strategy for OCD in their children requires scientific evaluation. Improving access to effective treatments for OCD would also improve tertiary prevention.

Does neuropsychological performance in OCD relate to different symptoms? A meta-analysis comparing the symmetry and obsessing dimensions

BACKGROUND

Investigations of neuropsychological functioning in obsessive-compulsive disorder (OCD) have produced mixed results for deficits in executive functioning (EF), attention, and memory. One potential explanation for varied findings may relate to the heterogeneity of symptom presentations, and different clinical or neurobiological characteristics may underlie these different symptoms.

METHODS

We investigated differences in neuropsychological functioning between two symptoms groups, obsessing/checking (O/C) and symmetry/ordering (S/O), based on data suggesting an association with different motivations: harm avoidance and incompleteness, respectively. Ten studies (with 628 patients) were included and each investigation assessed at least one of 14 neuropsychological domains.

RESULTS

The S/O domain demonstrated small, negative correlations with overall neuropsychological functioning, performance in EF, memory, visuospatial ability, cognitive flexibility, and verbal working memory. O/C symptoms demonstrated small, negative correlations with memory and verbal memory performance. A comparison of functioning between symptom groups identified large effect sizes showing that the S/O dimension was more strongly related to poorer neuropsychological performance overall, and in the domains of attention, visuospatial ability, and the subdomain of verbal working memory.

CONCLUSIONS

Findings support existing evidence suggesting that different OCD symptoms, and their associated core motivations, relate to unique patterns of neuropsychological functioning, and, potentially dysfunction in different neural circuits.

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.

A computerized neuropsychological evaluation of cognitive functions in a subclinical obsessive-compulsive sample

BACKGROUND AND OBJECTIVES

Ample research in obsessive-compulsive disorder (OCD) reveals a moderate degree of underperformance on various neuropsychological tasks. Less is known about neuropsychological function in subclinical obsessive-compulsive (OC) samples. Most analogue OCD studies did not use a comprehensive neuropsychological battery and none utilized a fully computerized battery. To fill this gap in the literature, the present study aimed at assessing cognitive functions in a subclinical OC sample using a validated computerized neuropsychological battery.

METHODS

Initially, a sample of 165 students completed the Obsessive-Compulsive Inventory-Revised (OCI-R). Using a psychometrically valid methodology, a high OC (HOC, n = 29) and low OC (LOC, n = 29) groups were selected based on scores in the upper and lower quartiles on the OCI-R. The two groups completed the NeuroTrax computerized neuropsychological battery and clinical questionnaires.

RESULTS

Although the HOC group underperformed on most outcome measures, controlling for state-anxiety and depression symptoms, no significant differences were found on major domains (i.e., memory, attention, executive functions, processing speed, visuospatial functions, verbal functions, and motor skills), and subdomains. Normalized scores, produced using population norms, indicated that both groups performed within the normative range.

LIMITATIONS

Not all neuropsychological subdomains were assessed.

CONCLUSIONS

Results are consistent with the general picture in analogue OC samples, and may be more reliable than paper-pencil testing, given that a full computerized neuropsychological battery minimizes examiner-examinee interactions, and increases timing accuracy. In sum, analogue OC samples, characterized by equivalent symptom severity but high functioning compared to OCD samples, do not present with cognitive deficits.

The Sensitivity of Three Versions of the Padua Inventory to Measuring Treatment Outcome and Their Relationship to the Yale-Brown Obsessive Compulsive Scale

The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and different versions of the Padua Inventory (PI) are frequently used instruments to measure symptoms of obsessive-compulsive disorder (OCD). However, little is known of how these different versions of the PI compare to each other in their sensitivity to measuring treatment outcome, and there is currently no adequate explanation to account for the weak relationships between self-report measures and the Y-BOCS. This study aimed to investigate the sensitivity of these measures to treatment outcome, and to examine whether differences in how they measure symptom severity can explain the weak relationships. Hypotheses were: (1) the Y-BOCS would be significantly more sensitive to measuring treatment outcome than the PI versions; (2) correlations between the measures would be significantly stronger for change scores as compared to relations measured at a single point in time; (3) weak relationships can be explained by the PI measuring symptom severity based on content and the Y-BOCS measuring symptoms, independent of content. Results showed that the Y-BOCS was significantly more sensitive to measuring treatment outcome than the PI versions, while differences between the questionnaires in which severity is measured can provide a partial account for why weak relations are observed between these measures.

Examining the role of sex differences in obsessive-compulsive symptom dimensions

Obsessive-compulsive disorder (OCD) is a notably heterogeneous disorder. As such, there has been increased interest in subtyping OCD into homogeneous entities using biological characteristics such as sex. Whereas there is large consensus in the literature regarding sex differences in the phenotypic expression of OCD, there are numerous disadvantages to how OCD has been previously measured and assessed. The present investigation explored potential sex differences in OCD symptoms using the Dimensional Obsessive Compulsive Scale (DOCS), a redesigned measure that more reliably assesses the four most commonly replicated OCD symptom dimensions. A large sample of community participants with elevated levels of OCD symptoms (N = 297) was recruited from an online crowdsourcing marketplace. Surprisingly, no differences in means were observed across sexes. However, results did reveal sex differences when examining relations between OCD dimensions. In particular, correlations between the OCD symptom dimensions were stronger in males compared to females. The common perception of OCD as a heterogeneous disorder may hold for females more so than for males. Future research should seek to replicate these findings using multimethod approaches including clinical, behavioral, and neuroimaging assessments.

Prefrontal cortex activation during neuropsychological tasks might predict response to pharmacotherapy in patients with obsessive-compulsive disorder

OBJECTIVE

We investigated oxyhemoglobin change in the prefrontal cortex (PFC) of patients with obsessive-compulsive disorder (OCD) who showed different responses to pharmacotherapy during neuropsychological tasks with near-infrared spectroscopy.

SUBJECTS AND METHODS

A total of 42 patients with OCD (mean age: 35.6±9.6 years, 14 men, 28 women) and healthy control subjects (mean age: 35.4±9.7 years, 13 men, 29 women) were selected. Patients with OCD were divided into three groups (responders to selective serotonin-reuptake inhibitors (SSRIs), responders to SSRIs with antipsychotics, and nonresponders to SSRIs and SSRIs with antipsychotics) based on pharmacological response. We investigated oxyhemoglobin change in the PFC of subjects during Stroop tasks and a verbal fluency test with near-infrared spectroscopy.

RESULTS

Responders to SSRIs showed smaller activation compared to control subjects during the Stroop incongruent task and verbal fluency test, but not during the Stroop congruent task. In contrast, responders to SSRIs with antipsychotics showed smaller activation compared to control subjects during all three tasks.

CONCLUSION

Our results suggest that activation of the PFC during Stroop tasks might predict responses to pharmacotherapy of patients with OCD.

Examining heterogeneity of obsessive-compulsive disorder: Evidence for subgroups based on motivations

Obsessive-compulsive disorder (OCD) is a heterogeneous illness and evidence suggests that different clinical characteristics may relate to varying treatment outcomes. This study was designed to identify subgroups based on core motivational domains in a clinical sample of individuals with OCD, and to compare groups on clinical characteristics. Cluster analyses identified four subgroups including groups with relatively high or low levels of both harm avoidance (HA) and incompleteness (INC) motivations. A subgroup was identified that demonstrated a "traditional profile" marked by high motivation to avoid harm, and elevated levels of beliefs about responsibility/overestimation of threat. The model also contained a subgroup characterized by high incompleteness, low motivation to avoid harm, and higher levels of perfectionistic beliefs and intolerance of uncertainty. Findings reemphasize that current cognitive and behavioral models of OCD may be enhanced by integrating incompleteness/NJREs.

Are obsessive-compulsive symptoms impulsive, compulsive or both?

BACKGROUND

The relationships between obsessive-compulsive symptoms and distinct forms of impulsivity and compulsivity are unclear. Such examination would be relevant in terms of how best to classify psychiatric disorders and in understanding candidate 'traits' that extend across a continuum between normalcy and clinical disorders.

METHOD

515 young adults (aged 18-29years) completed the Padua Inventory and undertook detailed clinical and neurocognitive assessments. Relationships between obsessive-compulsive symptoms and distinct types of impulsivity and compulsivity were evaluated using linear regression modeling.

RESULTS

Obsessive-Compulsive symptoms were significantly predicted by female gender, lower quality of life, psychiatric disorders in general (but not impulse control disorders), and worse extra-dimensional set-shifting. Obsessive-Compulsive symptoms were not significantly predicted by alcohol/nicotine consumption, stop-signal reaction times, or decision-making abilities.

CONCLUSION

These data indicate that obsessive-compulsive symptoms are more related to certain forms of compulsivity than to impulsivity. These findings have important implications for diagnostic conceptualizations and neurobiological models.

Obsessive-compulsive symptoms and attentional bias: An eye-tracking methodology

BACKGROUND AND OBJECTIVES

Cognitive models suggest that attentional biases are integral in the maintenance of obsessive-compulsive symptoms (OCS). Such biases have been established experimentally in anxiety disorders; however, the evidence is unclear in Obsessive Compulsive disorder (OCD). In the present study, an eye-tracking methodology was employed to explore attentional biases in relation to OCS.

METHODS

A convenience sample of 85 community volunteers was assessed on OCS using the Yale-Brown Obsessive Compulsive Scale-self report. Participants completed an eye-tracking paradigm where they were exposed to OCD, Aversive and Neutral visual stimuli. Indices of attentional bias were derived from the eye-tracking data.

RESULTS

Simple linear regressions were performed with OCS severity as the predictor and eye-tracking measures of the different attentional biases for each of the three stimuli types were the criterion variables. Findings revealed that OCS severity moderately predicted greater frequency and duration of fixations on OCD stimuli, which reflect the maintenance attentional bias. No significant results were found in support of other biases.

LIMITATIONS

Interpretations based on a non-clinical sample limit the generalisability of the conclusions, although use of such samples in OCD research has been found to be comparable to clinical populations. Future research would include both clinical and sub-clinical participants.

CONCLUSIONS

Results provide some support for the theory of maintained attention in OCD attentional biases, as opposed to vigilance theory. Individuals with greater OCS do not orient to OCD stimuli any faster than individuals with lower OCS, but once a threat is identified, these individuals allocate more attention to OCS-relevant stimuli..

Cognitive flexibility differentiates young adults exhibiting obsessive-compulsive behaviors from controls

The National Institute of Mental Health has proposed a shift toward classifying clusters of disorders on the basis of underlying biomarkers and neurological correlates. The present study sought to determine whether cognitive flexibility represents one such construct underlying obsessive-compulsive behaviors (OCBs), a cluster of behaviors characteristic of OCD and other body-focused repetitive behaviors (BFRBs), including trichotillomania, pathological skin picking, nail biting, and tic disorders. One-hundred and twenty-four undergraduate students completed the Depression Anxiety and Stress Scales, Padua Inventory-Washington State University Revision, Massachusetts General Hospital-Hairpulling Scale, Skin Picking Scale, and an Intradimensional/Extradimensional Shift (IDED) Test. Analyses were performed using a subsample of participants who met criteria for inclusion in the OCB group and a control group (N=56). Results indicated that young adults in the OCB group demonstrated significantly poorer performance on the IDED compared to controls. However, hierarchical regression analyses revealed that increased deficits in cognitive flexibility failed to predict worsened OCB severity-as assessed via a composite score. These results suggest that while cognitive flexibility differentiates those exhibiting OCBs from controls, it does not appear to be related to OCB severity. Future research is needed to replicate these results in larger clinical samples.

Response inhibition in a subclinical obsessive-compulsive sample

BACKGROUND AND OBJECTIVES

Inconsistent findings across studies challenge the viability of response inhibition (RI) as an endophenotype of obsessive-compulsive disorder (OCD). Contemporary conceptualization of endophenotypes in psychiatric disorders suggests that these markers vary continuously in the general population, highlighting the importance of analogue sample research. Although neuropsychological functions have been studied in subclinical obsessive-compulsive (OC) samples, no study to date had examined RI in the context of the go/no-go paradigm.

METHODS

A subclinical OC sample (HOC; n = 27) and a low OC symptoms control sample (LOC; n = 25), as determined by the Obsessive-Compulsive Inventory-Revised, completed a go/no-go task and clinical questionnaires.

RESULTS

The groups did not differ on age, gender, or state anxiety. Controlling for depressive severity, the HOC group made significantly more commission errors and exhibited larger response time variability on the go/no-go task. However, standardized scores produced using population norms revealed that the HOC group performed within normative range.

LIMITATIONS

This study used a non-clinical sample and no structured clinical screening was performed.

CONCLUSIONS

Compared to LOC participants, a psychometrically-defined subclinical OC sample exhibited deficient RI and sustained attention. However, when raw scores were converted to age and education adjusted standardized scores according to the test's population norms, the HOC group task performance was in the normative range. These results, are in line with findings in OCD samples, suggesting that moderate degree of RI deficiencies is associated with the presence of OC symptomatology regardless of clinical status. However, the conceptualization of RI underperformance as an OCD disorder-specific impairment, remains controversial.

Poor cognitive flexibility, and the experience thereof, in a subclinical sample of female students with obsessive-compulsive symptoms

Research indicates that people with obsessive-compulsive disorder (OCD) have poor cognitive flexibility. However, studies have largely focused on actual abilities and while individuals' emotional responses may be just as important, little is known about how those with OCD experience a situation that requires cognitive flexibility. It is furthermore largely unknown whether cognitive flexibility may also be important for people with OCD symptoms, rather than only to those with full blown disorders. This study investigates the relationship between cognitive flexibility, and the experience thereof in female students with and without OCD symptoms. It was expected that poor cognitive flexibility would be positively associated to OCD symptoms, and that those with OCD symptoms would display poor cognitive flexibility, and experience situations requiring cognitive flexibility as more difficult, than those without OCD symptoms. Participants completed a measure for OCD symptoms, a neuropsychological task to measure cognitive flexibility, and a self-report measure assessing emotional experience of situations requiring cognitive flexibility. Positive associations between OCD symptoms and both poor cognitive flexibility and negative experience of situations requiring cognitive flexibility were found. Furthermore, those with OCD symptoms performed poorer on the cognitive flexibility task than those without OCD symptoms, and reported higher scores on the cognitive inflexibility questionnaire. Results confirm a relation between OCD symptoms and poor cognitive flexibility in a subclinical sample and identify a relation between OCD symptoms and a negative experience of situations that require cognitive flexibility. Overall findings suggest that poor cognitive flexibility may be an important part of OCD symptomatology.

Neurobiological model of obsessive-compulsive disorder: evidence from recent neuropsychological and neuroimaging findings

Obsessive-compulsive disorder (OCD) was previously considered refractory to most types of therapeutic intervention. There is now, however, ample evidence that selective serotonin reuptake inhibitors and behavior therapy are highly effective methods for treatment of OCD. Furthermore, recent neurobiological studies of OCD have found a close correlation between clinical symptoms, cognitive function, and brain function. A large number of previous neuroimaging studies using positron emission tomography, single-photon emission computed tomography or functional magnetic resonance imaging (fMRI) have identified abnormally high activities throughout the frontal cortex and subcortical structures in patients with OCD. Most studies reported excessive activation of these areas during symptom provocation. Furthermore, these hyperactivities were decreased after successful treatment using either selective serotonin reuptake inhibitors or behavioral therapy. Based on these findings, an orbitofronto-striatal model has been postulated as an abnormal neural circuit that mediates symptomatic expression of OCD. On the other hand, previous neuropsychological studies of OCD have reported cognitive dysfunction in executive function, attention, nonverbal memory, and visuospatial skills. Moreover, recent fMRI studies have revealed a correlation between neuropsychological dysfunction and clinical symptoms in OCD by using neuropsychological tasks during fMRI. The evidence from fMRI studies suggests that broader regions, including dorsolateral prefrontal and posterior regions, might be involved in the pathophysiology of OCD. Further, we should consider that OCD is heterogeneous and might have several different neural systems related to clinical factors, such as symptom dimensions. This review outlines recent neuropsychological and neuroimaging studies of OCD. We will also describe several neurobiological models that have been developed recently. Advanced findings in these fields will update the conventional biological model of OCD.

Cognitive performance in a subclinical obsessive-compulsive sample 1: cognitive functions

Individuals who are not clinically diagnosed with obsessive-compulsive disorder (OCD) but still display obsessive-compulsive (OC) tendencies may show cognitive impairments. The present study investigated whether there are subgroups within a healthy group showing characteristic cognitive and emotional performance levels similar to those found in OCD patients and whether they differ from OCD subgroups regarding performance levels. Of interest are those cases showing subclinical symptomatology. The results revealed no impairments in the subclinical OC participants on the neuropsychological tasks, while evidence suggests that there exist high and low scores on two standardised clinical instruments (Yale-Brown Obsessive Compulsive Scale and Cognitive Assessment Instrument of Obsessions and Compulsions) in a healthy sample. OC symptoms may diminish the quality of life and prolong sustainable return to work. It may be that occupational rehabilitation programmes are more effective in rectifying subclinical OC tendencies compared to the often complex symptoms of diagnosed OCD patients. The relationship between cognitive style and subclinical OC symptoms is discussed in terms of how materials and information might be processed. Although subclinical OC tendencies would not seem to constitute a diagnosis of OCD, the quality of treatment programmes such as cognitive behavioural therapy can be improved based on the current investigation.

Neuropsychological deficits in drug naïve, non-depressed obsessive-compulsive disorder patients

There are several studies that compared neuropsychological performance of OCD patients with healthy controls. However, there are hardly any studies which have used drug-naïve as well as non-depressed OCD subjects in their studies. The present study compared eighteen drug-naïve non-depressed OCD patients with similar number of age, education and sex matched healthy controls on neuropsychological tests. The tests used are block design, object assembly, Visuospatial Working Memory Test, Verbal Working Memory Test, Complex Figure Test, Stroop Test and Wisconsin Card Sorting Test. In addition to usual significance testing, Effect Sizes were calculated. In addition, correlation was done between neuropsychological test variables and clinical variables. The results did not show any significant correlation between any of the clinical variables and neuropsychological test variables. On the other hand, patients showed significant deficits mainly in executive functions and organizational strategy with respect to visuospatial functions. The observed deficits can be attributed to both dorsolateral prefrontal cortex and orbitofrontal cortex involvement.

What checkers actually check: an eye tracking study of inhibitory control and working memory

BACKGROUND

Not only is compulsive checking the most common symptom in Obsessive Compulsive Disorder (OCD) with an estimated prevalence of 50-80% in patients, but approximately ∼15% of the general population reveal subclinical checking tendencies that impact negatively on their performance in daily activities. Therefore, it is critical to understand how checking affects attention and memory in clinical as well as subclinical checkers. Eye fixations are commonly used as indicators for the distribution of attention but research in OCD has revealed mixed results at best.

METHODOLOGY/PRINCIPAL FINDING

Here we report atypical eye movement patterns in subclinical checkers during an ecologically valid working memory (WM) manipulation. Our key manipulation was to present an intermediate probe during the delay period of the memory task, explicitly asking for the location of a letter, which, however, had not been part of the encoding set (i.e., misleading participants). Using eye movement measures we now provide evidence that high checkers' inhibitory impairments for misleading information results in them checking the contents of WM in an atypical manner. Checkers fixate more often and for longer when misleading information is presented than non-checkers. Specifically, checkers spend more time checking stimulus locations as well as locations that had actually been empty during encoding.

CONCLUSIONS/SIGNIFICANCE

We conclude that these atypical eye movement patterns directly reflect internal checking of memory contents and we discuss the implications of our findings for the interpretation of behavioural and neuropsychological data. In addition our results highlight the importance of ecologically valid methodology for revealing the impact of detrimental attention and memory checking on eye movement patterns.

The extended fronto-striatal model of obsessive compulsive disorder: convergence from event-related potentials, neuropsychology and neuroimaging

In this work, we explored convergent evidence supporting the fronto-striatal model of obsessive-compulsive disorder (FSMOCD) and the contribution of event-related potential (ERP) studies to this model. First, we considered minor modifications to the FSMOCD model based on neuroimaging and neuropsychological data. We noted the brain areas most affected in this disorder -anterior cingulate cortex (ACC), basal ganglia (BG), and orbito-frontal cortex (OFC) and their related cognitive functions, such as monitoring and inhibition. Then, we assessed the ERPs that are directly related to the FSMOCD, including the error-related negativity (ERN), N200, and P600. Several OCD studies present enhanced ERN and N2 responses during conflict tasks as well as an enhanced P600 during working memory (WM) tasks. Evidence from ERP studies (especially regarding ERN and N200 amplitude enhancement), neuroimaging and neuropsychological findings suggests abnormal activity in the OFC, ACC, and BG in OCD patients. Moreover, additional findings from these analyses suggest dorsolateral prefrontal and parietal cortex involvement, which might be related to executive function (EF) deficits. Thus, these convergent results suggest the existence of a self-monitoring imbalance involving inhibitory deficits and executive dysfunctions. OCD patients present an impaired ability to monitor, control, and inhibit intrusive thoughts, urges, feelings, and behaviors. In the current model, this imbalance is triggered by an excitatory role of the BG (associated with cognitive or motor actions without volitional control) and inhibitory activity of the OFC as well as excessive monitoring of the ACC to block excitatory impulses. This imbalance would interact with the reduced activation of the parietal-DLPC network, leading to executive dysfunction. ERP research may provide further insight regarding the temporal dynamics of action monitoring and executive functioning in OCD.

Deficient inhibition of return in subclinical OCD only when attention is directed to the threatening aspects of a stimulus

BACKGROUND

Inhibition of return (IOR) is thought to reflect inhibition of previously attended but irrelevant stimuli. Deficient IOR would increase the likelihood of revisiting previously searched locations or objects, thus leading to unproductive perseverations.

METHOD

Therefore, using a novel IOR task, we investigated whether high scoring checkers attentional biases to threat would result in dysfunctional inhibitory functioning compared to low checkers. In two tasks, we compared 53 subclinical high and 49 low checkers regarding IOR effects for stimuli that were concordant with the concerns of high but not of low checkers (electrical kitchen appliances: e.g., toaster, kettle). The difference between the two tasks was the cueing procedure. In one task, an appliance was switched "ON" and "OFF" as an unpredictive cue, drawing attention to the functionality of the stimulus.

RESULTS

In this task, IOR was specifically attenuated in high checkers. In the other task, however, the cue was more abstract in form of a yellow outline that appeared around one of two appliances. Although the appliance was either "ON" or "OFF," this did not seem to matter and high checkers revealed a typical IOR pattern similar to low checkers.

CONCLUSIONS

We conclude that IOR mechanisms might not be generally deficient in high checkers; rather only when attention is drawn to the threatening aspects of ecologically valid stimuli, then disengagement of attention is deficient in high checkers. We make suggestions on how our task-specific findings may inform cognitive interventions that target attentional control in the treatment of checking/obsessive-compulsive disorder.

Neuropsychological performance in OCD: a study in medication-naïve patients

BACKGROUND

Obsessive-compulsive disorder (OCD) is associated with impairments in multiple neuropsychological domains but the findings are rather inconsistent across studies. One potential reason for poor replication is the confounding influence of medications. There is limited research on neuropsychological performance in medication-naïve, never treated OCD patients.

METHODS

In this study, we assessed 31 medication-naïve, never-treated, DSM-IV OCD patients free of comorbid major depression and 31 healthy controls individually matched for age, gender and years of education, with tests of attention, executive function, memory reasoning and visuo-spatial function.

RESULTS

Medication-naïve OCD patients did not significantly differ from healthy controls on most neuropsychological tests. Patients performed somewhat poorly only on the highest goal hierarchy of the Tower of London (TOL) test (p=0.001, effect size=0.68).

CONCLUSIONS

It is intriguing to find that symptomatic, drug-naïve OCD patients did not significantly differ from healthy controls on most neuropsychological tests. Our finding of medium effect size on TOL highest goal hierarchy test suggests that brain regions outside the affective orbitofrontal loop may also be perhaps involved in OCD. This finding however needs replication because of modest effect size. Future studies should focus on studying medication-naïve, co-morbidity-free patients and relatives using symptom dimensions for consistent and robust findings.

Functional neuroimaging in obsessive-compulsive disorder

BACKGROUND AND AIM

Obsessive-compulsive disorder (OCD) is a severe, highly prevalent and chronically disabling psychiatric disorder that usually emerges during childhood or adolescence. This paper aims to review the literature on functional neuroimaging in OCD, analysing the reported dysfunctional connectivity in the corticostriatothalamocortical circuitry.

METHOD

This study included papers published in peer-reviewed journals dealing with functional imaging in OCD.

RESULTS

Striatal dysfunction, mainly of the caudate nucleus, leads to inefficient thalamic gating, resulting in hyperactivity within the orbitofrontal cortex (intrusive thoughts) and the anterior cingulate cortex (non-specific anxiety). Compulsions consist of ritualistic behaviours performed to recruit the inefficient striatum and neutralise unwanted thoughts and anxiety. Functional neuroimaging findings are discussed against the background of specific cognitive impairments, mainly regarding visuospatial processing, executive functioning and motor speed. Cognitive deficits are partial and specific, matching imaging data.

CONCLUSIONS

Several studies have targeted brain regions hypothesised to be involved in the pathogenesis of OCD, showing the existence of dysfunctional connectivity in the corticostriatothalamocortical circuitry. Improvements in spatial resolution of neuroimaging techniques may contribute to a better understanding of the neurocircuitry of OCD and other anxiety disorders.

Validation of a classification system of obsessive-compulsive spectrum disorder symptoms in a non-clinical sample

Controversy surrounds the classification of obsessive-compulsive spectrum disorder (OCSD) symptoms. In this study, we tested whether a broad OCSD symptoms model consisting of obsessive-compulsive, body dysmorphic, health anxiety, trichotillomania, pathological skin picking, impulsivity, and anxiety symptoms displayed sufficient data fit. Alternatively, we tested whether a reduced OCSD symptoms model consisting of obsessive-compulsive, body dysmorphic, health anxiety, trichotillomania, and pathological skin picking symptoms demonstrated superior fit. The reduced OCSD symptoms model demonstrated good data fit. However, the broader OCSD symptoms model only displayed marginal data fit. In context with other findings, results of this study support an OCSD symptoms dimension that includes obsessive-compulsive, body dysmorphic, health anxiety, trichotillomania, and pathological skin picking symptoms. Implications of these findings are discussed as they relate to proposed changes in the forthcoming edition of the Diagnostic and Statistical Manual.

Impaired executive functioning in subclinical compulsive checking with ecologically valid stimuli in a working memory task

We previously showed that working memory (WM) performance of subclinical checkers can be affected if they are presented with irrelevant but misleading information during the retention period (Harkin and Kessler, 2009, 2011). The present study differed from our previous research in the three crucial aspects. Firstly, we employed ecologically valid stimuli in form of electrical kitchen appliances on a kitchen countertop in order to address previous criticism of our research with letters in locations as these may not have tapped into the primary concerns of checkers. Secondly, we tested whether these ecological stimuli would allow us to employ a simpler (un-blocked) design while obtaining similarly robust results. Thirdly, in Experiment 2 we improved the measure of confidence as a metacognitive variable by using a quantitative scale (0–100), which indeed revealed more robust effects that were quantitatively related to accuracy of performance. The task in the present study was to memorize four appliances, including their states (on/off), and their locations on the kitchen countertop. Memory accuracy was tested for the states of appliances in Experiment 1, and for their locations in Experiment 2. Intermediate probes were identical in both experiments and were administered during retention on 66.7% of the trials with 50% resolvable and 50% irresolvable/misleading probes. Experiment 1 revealed the efficacy of the employed stimuli by revealing a general impairment of high- compared to low checkers, which confirmed the ecological validity of our stimuli. In Experiment 2 we observed the expected, more differentiated pattern: High checkers were not generally affected in their WM performance (i.e., no general capacity issue); instead they showed a particular impairment in the misleading distractor-probe condition. Also, high checkers’ confidence ratings were indicative of a general impairment in metacognitive functioning. We discuss how specific executive dysfunction and general metacognitive impairment may affect memory traces in the short- and in the long-term.

Nonverbal memory and organizational dysfunctions are related with distinct symptom dimensions in obsessive-compulsive disorder

Recent acceptance that obsessive-compulsive disorder (OCD) represents a heterogeneous phenomenon has underscored the need for dimensional approaches to this disorder. However little is known about the relation between neuropsychological functions and symptom dimensions. The purpose of this study was to identify the cognitive deficits correlated with specific symptom dimensions. Thirteen categories in the Yale-Brown Obsessive Compulsive Scale symptom checklist from 144 patients with OCD were analyzed by principal component analysis. Correlations between identified symptom dimensions and neuropsychological functioning, measured by the Boston Qualitative Scoring System, were analyzed. Five factors or dimensions were identified: contamination/cleaning, hoarding, symmetry/ordering, obsessions/checking, and repeating/counting. Dysfunctions in nonverbal memory and organizational strategies were related to the symmetry/ordering dimension and the obsessions/checking dimension, respectively. The results of the present study support a transculturally stable symptom structure for OCD. They also suggest the possibility that nonverbal memory dysfunction and organizational impairment are mediated by distinct obsessive-compulsive dimensions.

Functional magnetic resonance imaging during planning before and after cognitive-behavioral therapy in pediatric obsessive-compulsive disorder

OBJECTIVE

Pediatric obsessive compulsive disorder (OCD) has been associated with cognitive abnormalities, in particular executive impairments, and dysfunction of frontal-striatal-thalamic circuitry. The aim of this study was to investigate if planning as an executive function is compromised in pediatric OCD and is associated with frontal-striatal-thalamic dysfunction, and if this dysfunction would normalize after successful treatment.

METHOD

Twenty-five medication-free pediatric patients (mean ± SD 13.95 ± 2.52 years old, range 9 to 19 years) with OCD and 25 healthy controls, matched by age and gender, were scanned twice using a self-paced pseudo-randomized event-related functional magnetic resonance imaging version of the Tower of London. Patients were rescanned after 16 sessions of protocol-based cognitive behavioral therapy; healthy controls were rescanned after a similar interval.

RESULTS

Patients performed the task significantly slower but with similar accuracy compared with controls. Neuroimaging results showed less recruitment of frontal and parietal regions in patients with OCD compared with controls during the planning versus control task. With increasing task load patients compared with controls showed more recruitment of ventrolateral and medial prefrontal cortex and insula and anterior cingulate cortex. After treatment, these differences ceased to be significant, with time by group by task load interaction analyses showing a significant decrease in right posterior prefrontal activity in patients with OCD compared with healthy controls.

CONCLUSION

Pediatric patients with OCD showed subtle planning impairments and decreased dorsolateral prefrontal and parietal recruitment that normalized after cognitive behavioral treatment. Planning dysfunction is likely to be a state rather than a trait feature of pediatric OCD.

Nonclinical obsessive-compulsive symptoms and executive functions in schizophrenia

The impact of nonclinical obsessive-compulsive symptoms (OCS) on neuropsychological functioning in schizophrenia has received little investigation. The authors evaluated whether severity and subtype of OCS are associated with executive functioning in schizophrenia. Twenty-nine patients with schizophrenia and 32 healthy comparison subjects completed questionnaire and performance-based measures of executive functioning. Overall OCS severity in patients was associated with poorer monitoring and cognitive flexibility. Obsessing, hoarding, and checking were related to poorer executive functioning in daily life. Performance-based scores showed few correlations with OCS. Findings indicate that severity of nonclinical OCS subtypes contributes to the heterogeneity of executive functions in schizophrenia.

Duration effect of obsessive-compulsive disorder on cognitive function: a functional MRI study

BACKGROUND

The inconsistency of previous reports examining cognitive function in obsessive-compulsive disorder (OCD) suggests its heterogeneity. In this study, we examined the effect of illness duration on cognitive function in OCD.

METHODS

We examined the cognitive function of 32 OCD patients and 16 healthy volunteers by neuropsychological tests and functional magnetic resonance imaging while they performed the Stroop and N-back tasks to assess attention and nonverbal memory. The patients were divided into two groups by illness duration: a short-term group (n=17, 5.5+/-3.1 years) and a long-term group (n=15, 20.3+/-6.1 years). Statistical analysis was performed to determine the differences between these two groups and the normal control group (n=16).

RESULTS

The long-term group showed attention deficit and nonverbal memory dysfunction on the neuropsychological tests. In contrast, on functional magnetic resonance imaging, the short-term group showed weaker activation of the right caudate during the Stroop task and stronger activation of the right dorso-lateral prefrontal cortex during the N-back task than the long-term and normal control groups.

CONCLUSIONS

The results suggested that abnormal brain activation occurs in the early phase of OCD and that the long-term persistence of OCD might involve a decline in cognitive function.

Continuous performance test in drug-naïve patients with obsessive-compulsive disorder: a case-controlled study

Twenty drug-naïve patients with obsessive-compulsive disorder (OCD) were compared with matched controls on their performance of the Continuous Performance Test (CPT). There was no difference on any measure of the CPT in the two groups. Higher obsession scores, rather than compulsion scores, were associated with poorer sensitivity of the CPT in drug-naïve OCD patients.

Measuring obsessive-compulsive symptoms: Padua Inventory-Revised vs. Yale-Brown Obsessive Compulsive Scale

Although the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Padua Inventory-Revised (PI-R) are the most widely used instruments for assessing presence and severity of symptoms in obsessive-compulsive disorder (OCD), the correlation between the two instruments is surprisingly low. The aim of the present investigation was to test two possible explanations for the discrepancy between these instruments by comparing both scales in 120 OCD patients. The tested hypotheses included: (1) differences in the way the measures are administered, i.e. observer-rated vs. self-rated; and (2) differences in the way severity is calculated, i.e. the PI-R measures severity by aggregating symptoms, while the Y-BOCS measures severity unrelated to the number of symptoms. Results indicated that neither hypothesis satisfactorily explains the differences between the measures. The investigation concludes that the Y-BOCS and PI-R measure relatively unrelated features of OCD, and the combined use of multiple measures is recommended to assess the complexity of OCD phenomena.

MOOD IN RELATION TO SUBCLINICAL OBSESSIVE-COMPULSIVE SYMPTOMS

Obsessive-compulsive disorder (OCD) is considered an anxiety disorder, but shows comorbidity with other disorders in the affective and impulsive-compulsive spectra, including anxiety disorders, major depression, and drug addictions. Subclinical OCD symptoms are relatively common in nonclinical populations and share common neurobiological substrates with clinical OCD. In this nonclinical community sample, the relationship between the severity of obsessions and compulsions, as measured by the Yale-Brown Obsessive Compulsive Scale, related to the intensity of negative emotions (anger, depression, tension, confusion, and fatigue) but not positive emotion (vigor), as measured by the Profile of Mood States. These relationships were independent of demographic influences and psychoactive drug use frequency (alcohol, cannabis, opioid, major stimulants, MDMA, and hallucinogens). These likely reflect common neurobiological substrates for emotional and behavioral regulation in prefrontal-subcortical/limbic circuits, which show normal variations in the general population.

Concurrent validity of the tower tasks as measures of executive function in adults: a meta-analysis

Executive function refers to a variety of behaviors and abilities related to planning and strategy use, as well as to the maintenance of attention and behavior in the pursuit of some goal. Many instruments have been designed for the purpose of assessing executive function, and the tower tasks represent a specific group of measures commonly used in the assessment of this construct. This review and meta-analysis examines the theoretical and psychometric basis for the use of the various tower tasks in neuropsychological assessment of adults. Neuroimaging and electrophysiological evidence are consistent with theoretical hypotheses of frontal involvement (e.g., planning and strategy use) in tower task performance. Further, adults with various disorders of presumed neurological basis demonstrate impaired performance on tower tasks. Implications for the use of tower tasks in practice and research are discussed.

Nonverbal memory dysfunction in obsessive-compulsive disorder patients with checking compulsions

Obsessive-compulsive disorder (OCD) is a clinically heterogeneous disorder; nonetheless, most of the previous neuropsychological studies for assessing the involvement of memory dysfunction grouped together patients with different symptoms, thereby potentially accounting for the inconsistencies of results. The goals of this study were to compare the memory dysfunction of two main subtypes of OCD and to identify the type of memory dysfunction that is associated with the checking symptoms in OCD patients. The sample population comprised the cleaning-type OCD group (N=23), checking-type OCD group (N=24), and a control group of healthy volunteers (N=20). All the OCD patients were selected from the outpatient clinic. All the subjects underwent the Rey-Osterreith Complex Figure Test (RCFT) for the assessment of nonverbal memory function, the Hopkins Verbal Learning Test (HVLT) for verbal memory function, the Wechsler Adult Intelligence Scale-Revised (WAIS-R), and the Wisconsin Card Sorting Test (WCST). The immediate and delayed memory scores of RCFT were significantly lower in the checking-type OCD group; there were no significant differences in HVLT scores amongst the three groups. Our results indicate that the checking-type compulsion of OCD patients is associated with nonverbal memory deficits and not with verbal memory deficits.

The neuropsychological profile of a subclinical obsessive-compulsive sample

We investigated the neuropsychological profile of subjects in a subclinical obsessive-compulsive disorder (OCD) sample. Psychometrically defined subclinical obsessive-compulsive (n = 21) and control (n = 22) subjects were examined. Comprehensive neuropsychological tests evaluating verbal/nonverbal memory, attention, and executive function were administered. The subclinical obsessive-compulsive group showed poorer performances on the Wisconsin Card Sorting Test (WCST), F(1, 41) = 13.80, p < .001, and Trail-Making Test (TMT), F(1, 41) = 5.48, p < .05, compared with the control group. The subclinical obsessive-compulsive group showed higher rates of total errors, perseverative errors, and perseverative responses. In addition, the subclinical obsessive-compulsive group committed a greater number of errors in the TMT. However, the groups showed no performance differences in the TMT after controlling for the effects of depression and anxiety, F(1, 39) = 0.11, p = .739. These results suggest that subclinical obsessive-compulsives seemed to display deficits in executive functioning. This neuropsychological profile is consistent with current theories proposing that executive dysfunction may serve as the pathophysiological mechanism underlying the development of obsessive-compulsive disorder.

Executive and attention functioning among children in the PANDAS subgroup

Evidence from past studies indicates that adults and children with Obsessive-Compulsive Disorder (OCD) and Tourette syndrome (TS) experience subtle neuropsychological deficits. Less is known about neuropsychological functioning of children and adolescents with a symptom course consistent with the PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infection) subgroup of OCD and tics. To provide such information, we administered three tests of attention control and two of executive function to 67 children and adolescents (ages 5-16) diagnosed with OCD and/or tics and a symptom course consistent with the PANDAS subgroup and 98 healthy volunteers (HV) matched by age, sex, and IQ. In a paired comparison of the two groups, the PANDAS subjects were less accurate than HV in a test of response suppression. Further, in a two-step linear regression analysis of the PANDAS group in which clinical variables were added stepwise into the model and in the second step matching variables (age, sex, and IQ) were added, IQ emerged as a predictor of performance on this task. In the same analysis, ADHD diagnosis and age emerged as predictors of response time in a continuous performance task. Subdividing the PANDAS group by primary psychiatric diagnosis revealed that subjects with TS or OCD with tics exhibited a longer response time compared to controls than subjects with OCD only, replicating previous findings within TS and OCD. This study demonstrates that children with PANDAS exhibit neuropsychological profiles similar to those of their primary psychiatric diagnosis.

A study of neuropsychological deficit in children with obsessive-compulsive disorder

This study was conducted to examine the neuropsychological deficits in children with obsessive compulsive disorder (OCD). Furthermore, the focus of present study was to explore whether OCD children show the same executive dysfunction as adult OCD patients. The participants consisted of 106 children between the ages of 6 and 16 years who visited the department of child-adolescent psychiatry, Seoul National University Children's Hospital (17 OCD, 25 ADHD, 21 tic disorder, 20 depressive disorder, and 23 healthy children). The OCD children showed higher verbal ability compared to other psychiatric groups, but performed the worst on WISC-R subtests assessing perceptual organization ability under time pressure. The OCD children did not show any significant deficits in verbal intellectual function, memory, attention and concentration abilities. However, similar to the ADHD children, the OCD children had significantly more errors and completed fewer categories on the WCST compared to the healthy group. Through neuropsychological tests, the OCD children showed cognitive strength and weakness similar to those of OCD adults that were reported in previous research. Specifically, they had executive function deficits in mental set shifting, supporting the frontal-striatal dysfunction hypothesis of OCD in children as well as in adults.

Neuropsychological performance in children and adolescents with obsessive-compulsive disorder and influence of clinical variables

BACKGROUND

Several studies have found impairment in visual memory and visual organization in adults with obsessive-compulsive disorder (OCD), but little is known about the neuropsychological profile of children and adolescents with this disorder. The influence of clinical variables such as age, severity of obsessive-compulsive symptomatology, depressive symptomatology, and pharmacological treatment on cognitive performance in these patients has not been thoroughly studied.

METHODS

A neuropsychological battery designed for this study was administered to 35 patients with DSM-IV-TR diagnosis of OCD without psychiatric comorbidity aged between 7 and 18 years and 35 gender- and age-matched healthy subjects.

RESULTS

Children and adolescents with OCD performed significantly worse on verbal and visual memory and velocity. When depressive symptomatology was controlled, impairment in visual memory, visual organization, and velocity again was found, but impairment in verbal memory was not. Neuropsychological impairment was not related to age, obsessive-compulsive severity, and pharmacological treatment.

CONCLUSIONS

Children and adolescents with OCD without psychiatric comorbidity with acute illness show impairment in visual memory, visual organization, and velocity, similar to adults. The influence of depressive symptomatology is important in cognitive performance. No relation was found between neuropsychology and age, severity of obsessive-compulsive symptomatology, or pharmacological treatment in this study.

Spatial working memory in obsessive-compulsive disorder improves with clinical response: A functional MRI study

To date, only a few studies have examined whether executive dysfunctions in obsessive-compulsive disorder (OCD) are state or trait dependent and almost none of these studies have used functional neuroimaging techniques. We conducted a functional MRI study before and after 12 weeks of pharmacological treatment in 14 psychotropic-free patients with OCD without comorbidity. Subjects performed a spatial variant of a working memory task with four increasing levels of difficulty (n-back task). Responders and non-responders did not differ in clinical and demographical characteristics or brain activation patterns before treatment. Performance improved only in responders and was associated with a change in the overall pattern of brain activity during the task. We found no correlations between (changes in) scores on symptom scales, brain activity and performance. Our preliminary findings suggests that spatial working memory deficits in OCD and their functional anatomical correlates, as assessed with a spatial n-back task, are, at least to some extent, state dependent.