Reduced design fluency in subclinical obsessive-compulsive subjects

Capturing Subtle Neurocognitive Differences in Children with and without Tourette Syndrome through a Fine-Grained Analysis of Design Fluency Profiles

BACKGROUND

Tourette syndrome (TS) can be accompanied by neurocognitive impairment. Only a few studies have focused on executive function assessment in TS using design fluency, providing preliminary results. This study aimed to characterize the detailed design fluency profile of children with TS compared with neurotypical children, while addressing the central concern of frequent comorbidities in studies on TS by considering tic severity and attention-deficit/hyperactivity disorder (ADHD) symptoms and diagnosis.

METHODS

Sixty-one children aged between 6 and 15 years participated and were divided into a TS group (n = 28 (with ADHD n = 15)) and a control group (n = 33). Our objective was addressed by examining a wide range of measures of the Five-Point-Test, presumably sensitive to frontostriatal dysfunction. The total number of designs, repetitions, repetition ratio, unique designs, and numerical, spatial, and total strategies were examined for the total duration of the test (global measures) and at five equal time intervals (process measures).

RESULTS

The TS group produced significantly fewer numerical strategies. Groups did not differ in other global or process measures. ADHD did not affect performance.

CONCLUSIONS

Children with TS do not inherently show general executive dysfunction but may present with subtle neurocognitive characteristics here revealed by comprehensive design fluency profiles.

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.

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.

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.

Frontal brain asymmetry in depression with comorbid anxiety: a neuropsychological investigation

The approach-withdrawal model posits that depression and anxiety are associated with a relative right asymmetry in frontal brain activity. Most studies have tested this model using measures of cortical brain activity such as electroencephalography. However, neuropsychological tasks that differentially use left versus right frontal cortical regions can also be used to test hypotheses from the model. In two independent samples (Study 1 and 2), the present study investigated the performance of currently depressed individuals with or without a comorbid anxiety disorder and healthy controls on neuropsychological tasks tapping primarily left (verbal fluency) or right (design fluency) frontal brain regions. Across both samples, results indicated that comorbid participants performed more poorly than depressed only and control participants on design fluency, while all groups showed equivalent performance on verbal fluency. Moreover, comorbid participants showed "asymmetrical" performance on these two tasks (i.e., poorer design [right frontal] relative to verbal [left frontal] fluency), whereas depressed only and control participants showed approximately symmetrical profiles of performance. Results from these two samples suggest an abnormal frontal asymmetry in neurocognitive performance driven primarily by right frontal dysfunction among anxious-depressed individuals and highlight the importance of considering comorbid anxiety when examining frontal brain functioning in depression.

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.

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.

Memory and executive functioning in obsessive-compulsive disorder: a selective review

BACKGROUND

The neurocognitive deficits that underlie the unique features of obsessive-compulsive disorder (OCD) are not yet completely understood. This paper reviews the main neuropsychological findings in memory and executive functioning in this disorder, and examines a number of challenges facing this area of research.

METHOD

A selective review of the neuropsychological literature on OCD was conducted using MEDLINE and drawing on literature known to the authors.

RESULTS

The neuropsychological profile of OCD appears to be one of primary executive dysfunction. Although memory functioning may be affected, these deficits appear secondary to an executive failure of organizational strategies during encoding. On tasks of executive functioning patients with OCD demonstrate increased response latencies, perseveration of responses, and difficulties utilizing feedback to adapt to change.

LIMITATIONS

A statistical meta-analysis was not performed and only the cognitive domains of memory and executive functioning were examined.

CONCLUSIONS

Given the prominence of chronic doubt and indecision in clinical settings, it is surprising that decision making as a cognitive construct as related to OCD has not received greater attention in the neuropsychological literature. On the basis of emerging literature we suggest that it is a potential area of dysfunction and one that warrants further investigation as it may assist in enhancing our understanding of the pathophysiology of OCD.

Interrater and Test–Retest Reliability of a Fixed Condition Design Fluency Test

Despite its potential as a unique neuropsychological test, the emergence of a psychometrically sound research foundation for Jones-Gotman and Milner's (1977) Design Fluency Test (DFT) has been constrained by the lack of consistent administration and scoring practices and limited information about its reliability. Here we describe an approach to administering and scoring the fixed condition DFT that is modeled on Jones-Gotman and Milner's original method and that clarifies procedural ambiguities. Results include interrater and long-term test-retest reliability analyses using this approach. First, based on five raters who scored 50 DFT protocols, good to excellent intra-class correlation coefficients were obtained for all DFT scores. Second, in a broadly representative sample of 87 healthy adults who were tested twice over an average of 5 1/2 years, the test-retest reliabilities for total and novel design scores ranged from good to excellent. This study demonstrates that the fixed condition DFT can be scored reliably using these procedures and that the reliability coefficients for DFT total and novel designs scores are comparable to those of other commonly used neuropsychological tests.

Common and distinct neural correlates of obsessive-compulsive and related disorders

Obsessive-compulsive disorder (OCD) often co-occurs with other anxiety disorders and a number of other disorders of similar phenomenology known as the "OCD spectrum" disorders. Neurobiologically, it is unclear how all these disorders relate to each other. The picture is further complicated by the clinical heterogeneity of OCD itself. This article reviews the literature on the common and distinct neural correlates of OCD, its symptom dimensions, and other anxiety and OCD spectrum disorders with the hope of providing a conceptual and heuristic framework to help understand the relationship between these phenomena.

A meta-analytic review of Wisconsin Card Sorting Test and verbal fluency performance in obsessive-compulsive disorder

INTRODUCTION

Abnormalities in associative frontostriatal circuits are often associated with obsessive-compulsive disorder (OCD), leading many researchers to predict that executive dysfunction should be particularly pronounced. However, deficits on putative tests of this construct have not consistently been identified.

METHODS

The present study used quantitative techniques to integrate results from 32 studies that assessed OCD patients' performance on tests of phonemic fluency, semantic fluency, and/or the Wisconsin Card Sorting Test (WCST).

RESULTS

As has been found for patients with focal frontal (but not focal nonfrontal) cortical lesions, relative to healthy controls OCD patients were comparably impaired on tests of phonemic and semantic fluency (rs = .33 and .37, respectively). However, in contrast to patients with focal frontal lobe injuries, fluency deficits did not qualify as differential deficits relative to psychomotor speed. Moreover, although a prominent view in the literature is that set-shifting is particularly compromised, the WCST was less sensitive to the presence of OCD than phonemic and semantic fluency, and also failed to qualify as a differential deficit.

CONCLUSIONS

For patients with OCD, deficits on tests of verbal fluency and the WCST do not appear to reflect executive dysfunction, but are instead consistent with a more generalised cognitive impairment.

Selective cognitive deficits in obsessive-compulsive disorder compared to panic disorder with agoraphobia

OBJECTIVE

Visual-spatial and executive functions deficits have been reported in obsessive-compulsive disorder (OCD). We investigated their specificity comparing cognitive function in OCD, panic disorder with agoraphobia (PD/A) and controls by a comprehensive neuropsychological battery.

METHOD

Fifty-five subjects (25 OCD, 15 PD/A, 15 controls) without current depressive episode underwent structured clinical interview for DSM-IV, Yale-Brown Obsessive Compulsive Scale, Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale. Neuropsychological battery assessed: executive functions, visual discrimination, spatial memory and learning, verbal memory, general intellectual functioning.

RESULTS

OCD showed controlled fluency, visual-spatial construction, learning and memory deficits; PD/A spatial learning impairment. OCD was discriminated from PD/A and controls by three tests scores, predicting group membership for 76.4% of the cases.

CONCLUSION

Visual-constructive and controlled fluency deficits seem specific in OCD, while the spatial learning deficit, shared with PD patients, may not be disorder-specific, but anxiety-related. Results support the proposed ventral frontal-striatal circuit involvement in OCD.

Patterns of neural response to emotive stimuli distinguish the different symptom dimensions of obsessive-compulsive disorder

Despite its heterogeneous symptomatology, obsessive-compulsive disorder (OCD) is currently conceptualized as a unitary diagnostic entity. Recent factor-analytic studies have identified several OCD symptom dimensions that are associated with different demographic variables, comorbidity, patterns of genetic transmission, and treatment response. Functional abnormalities in neural systems important for emotion perception, including the orbitofrontal cortex, lateral prefrontal cortex, anterior cingulate gyrus, and limbic regions, have been reported in OCD. In this review, we discuss the extent to which neurobiological markers may distinguish these different symptom dimensions and whether specific symptom dimensions, such as contamination/washing, are associated with abnormalities in emotion and, in particular, disgust, perception in OCD. Also discussed are findings that indicate that anxiety can be induced in healthy volunteers in response to OCD symptom-related material, and that associated increases in activity within neural systems important for emotion perception occur to washing- and hoarding-related material in particular in these subjects. Further examination of neural responses during provocation of different symptom dimensions in OCD patients will help determine the extent to which specific abnormalities in neural systems underlying emotion perception are associated with different symptom dimensions and predict treatment response in OCD.

Neuropsychological performance in obsessive-compulsive disorder: a critical review

There is growing evidence for neuropsychological dysfunction in obsessive-compulsive disorder (OCD) related to an underlying frontal lobe and/or basal ganglia dysfunction. The following paper is a systematical review of the existing literature on cognitive impairment in OCD patients. Fifty studies were surveyed with regard to methodological aspects and cognitive impairments found in OCD patients. In addition, the impact of confounding variables such as psychotropic medication, co-morbidity or severity of symptoms on neuropsychological functioning as well as effects of treatment are discussed. OCD is often related to memory dysfunction that seems to be associated with impaired organization of information at the stage of encoding. Several other executive functions are also commonly disturbed, though results are inconsistent. The results of our study suggest that some cognitive deficits seem to be common in OCD, but future studies should focus more on possible confounding variables such as co-morbidity or psychotropic medication.

Neural correlates of anxiety associated with obsessive-compulsive symptom dimensions in normal volunteers

BACKGROUND

The neural correlates of anxiety associated with obsessive-compulsive symptomlike provocation in normal volunteers are unknown.

METHODS

Ten healthy volunteers participated in four functional magnetic resonance experiments. Subjects were scanned while viewing alternating blocks of emotional (normally aversive, washing-relevant, checking-relevant, or hoarding-relevant pictures) and neutral pictures, and imagining scenarios related to the content of each picture type. Nonparametric brain mapping analyses were used.

RESULTS

In response to the provocative pictures in all experiments, increases in subjective anxiety and activation in bilateral ventral prefrontal, limbic, dorsal prefrontal, and visual regions were demonstrated. Anxiety related to different symptom dimensions was associated with different patterns of activation: provocation of washing-relevant anxiety predominantly activated dorsal and ventral prefrontal regions; checking-relevant anxiety predominantly activated dorsal prefrontal regions; and hoarding-relevant anxiety predominantly activated ventral prefrontal regions and the left amygdala.

CONCLUSIONS

Our findings support a dimensional model of obsessive-compulsive disorder (OCD) whereby 1) the brain systems implicated in the mediation of anxiety in response to symptom-related material in normal subjects are similar to those identified in OCD patients during symptom provocation, and 2) anxiety associated with different symptom dimensions is associated with differential patterns of activation of these neural systems. Further investigation of the neural basis of OCD symptom dimensions is required.

Neuropsychological performance in medicated vs. unmedicated patients with obsessive-compulsive disorder

To date, there have been no formal investigations of neuropsychological performance in patients with obsessive-compulsive disorder (OCD) taking psychotropic medications. The purpose of this study was to determine whether medicated and unmedicated patients with OCD demonstrate differences in neuropsychological functioning. Fifty-two patients with a primary DSM-IV diagnosis of OCD participated in the study; 28 were taking serotonin reuptake inhibitors (SRIs), and 24 were treatment-naïve (n=8) or had finished a washout period prior to their inclusion in other studies (n=16). The groups were well matched with regard to demographic and clinical variables, including symptom severity. Each group was administered a comprehensive neuropsychological battery to assess general intelligence, attention, verbal and non-verbal working memory, declarative and procedural learning, visuo-constructive skills, and executive functions. SRI-medicated did not differ from SRI-free patients on any neuropsychological measure. Benzodiazepines seemed to improve the patients' functioning on a semantic verbal fluency test. In addition, there were significant interactions between SRIs and benzodiazepines on the perseverative errors of the Wisconsin Card Sorting Test and on reaction times. SRI-medicated patients with OCD are able to perform on cognitive functioning tests at a comparable level with that of SRI-free patients, and these results have positive implications for OCD patients who respond to SRIs. The interactions between SRIs and benzodiazepines and their effect on cognition in OCD are likely to be complex and deserve further study.

Impairment of incidental memory for frequency in patients with obsessive-compulsive disorder

The aim of our study was to investigate whether patients with obsessive-compulsive disorder (OCD) have impaired incidental memory for frequency. Fifty-four subjects (27 OCD patients and 27 matched control subjects) performed a task assessing estimation of occurrence of previously heard words. Performance on this task was compared with other intentional verbal memory tasks (recognition, recall and learning of common words). We also correlated memory for frequency with frontal lobe tests (Wisconsin Card Sorting Test, Trail Making Tests A and B, and verbal fluency). Performance on incidental learning of frequency was significantly worse in the OCD group than in control subjects. Other verbal memory measures did not show significant differences. Performance in the frequency task correlated with verbal fluency. Although intentional verbal memories are normal in OCD patients, incidental memory for frequency is impaired, suggesting that prefrontal systems are involved in OCD.