Missing the forest for the trees? Deficient memory for linguistic gist in obsessive-compulsive disorder

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

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

Word recognition memory and serum levels of Borna disease virus specific circulating immune complexes in obsessive-compulsive disorder

BACKGROUND

Borna disease virus 1 (BoDV-1) is a non-segmented, negative-strand RNA virus that persistently infects mammals including humans. BoDV-1 worldwide occurring strains display highly conserved genomes with overlapping genetic signatures between those of either human or animal origin. BoDV-1 infection may cause behavioral and cognitive disturbances in animals but has also been found in human major depression and obsessive-compulsive disorder (OCD). However, the impact of BoDV-1 on memory functions in OCD is unknown.

METHOD

To evaluate the cognitive impact of BoDV-1 in OCD, event-related brain potentials (ERPs) were recorded in a continuous word recognition paradigm in OCD patients (n = 16) and in healthy controls (n = 12). According to the presence of BoDV-1-specific circulating immune complexes (CIC), they were divided into two groups, namely group H (high) and L (low), n = 8 each. Typically, ERPs to repeated items are characterized by more positive waveforms beginning approximately 250 ms post-stimulus. This "old/new effect" has been shown to be relevant for memory processing. The early old/new effect (ca. 300-500 ms) with a frontal distribution is proposed to be a neural correlate of familiarity-based recognition. The late old/new effect (post-500 ms) is supposed to reflect memory recollection processes.

RESULTS

OCD patients were reported to show a normal early old/new effect and a reduced late old/new effect compared to normal controls. In our study, OCD patients with a high virus load (group H) displayed exactly these effects, while patients with a low virus load (group L) did not differ from healthy controls.

CONCLUSION

These results confirmed that OCD patients had impaired memory recollection processes compared to the normal controls which may to some extent be related to their BoDV-1 infection.

The memory deficit hypothesis of compulsive checking in OCD: what are we really talking about? A narrative review

We reviewed studies that have specifically explored the memory deficit hypothesis of Obsessive Compulsive Disorder (OCD) checking, highlighting the methodological differences between these studies that may explain inconsistencies regarding memory deficits in OCD checkers. Based on Conway's proposition that one function of episodic memories is to keep an adaptive record of recent goal processing in order to check that actions have actually been accomplished, we suggest that impaired autonoetic consciousness -one of the main features of episodic memory- may be at the heart of the issue of checking compulsion. Autonoetic consciousness, that can be experimentally assessed by the Remember/Know/Guess paradigm,could be impaired in OCD checkers leading them to be unable to mentally relive their actions in order to be assured that they have been accomplished (e.g., having locked the door). We make methodological suggestions to improve the assessment of autonoetic consciousness deficit in OCD checkers and understand its role in the etiology and maintenance of compulsive checking.

Prospective memory in obsessive compulsive disorder

Studies on the nature and extent of prospective memory impairment in patients with obsessive-compulsive disorder are relatively scarce. The present study examined prospective memory in patients with obsessive-compulsive disorder in comparison to patients with schizophrenia and healthy controls. Prospective memory was assessed using Memory for Intentions Screening Test (MIST). Further, the participants were administered Delis-Kaplan Executive Function System Tower Test, Wisconsin Card Sorting Test, and Stroop Test for assessing their planning ability, mental flexibility and cognitive inhibition, respectively. Monitoring was assessed by frequency of clock checking. Results indicated that as compared to healthy controls, the patients with obsessive-compulsive disorder performed poorly on both time- and event-based prospective memory tasks, whereas, patients with schizophrenia performed poorly on time-based prospective memory task only. Further, both the patient groups had comparable performance across time- and event-based tasks. Results of error analysis indicated that patients with obsessive-compulsive disorder mainly committed no response and task substitution errors, whereas patients with schizophrenia committed no response errors. Except monitoring, none of the neurocognitive variables correlated with time or event-based prospective memory in any group. The findings are discussed in the light of their implications for retraining of prospective memory deficits in patients with obsessive-compulsive disorder and schizophrenia.

Examining neurocognition in body dysmorphic disorder using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS): A comparison with obsessive-compulsive disorder

Body dysmorphic disorder (BDD) is characterised by (i) an excessive preoccupation with an imagined defect in appearance, as well as (ii) repetitive behaviours and/or mental acts that occur in response to the preoccupation. To date, neuropsychological investigations have been limited. This study examined performance on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), tapping into five indices of neurocognition: (i) Immediate Memory, (ii) Visuospatial Construction, (iii) Language, (iv) Attention, and (iv) Delayed Memory. Twenty-one BDD participants were compared with 19 obsessive-compulsive disorder (OCD) participants and 21 healthy controls (HC), who were age-, sex-, and IQ-matched. Results indicated the BDD and OCD groups demonstrated poor overall neuropsychological performance (i.e. total RBANS) as well as deficits on the indices of Immediate Memory and Attention. Further group differences involving the subtests of Story Memory, Digit Span, and Story Recall were detected. Neuropsychological impairment in BDD with indicated similarities in OCD were corroborated. Future research should extend investigations focusing on gist and delayed memory, and aspects of attentional processing.

Differential memory effects for encoding and retrieving disorder-relevant contents in relation to checking

BACKGROUND AND OBJECTIVES

Obsessive-compulsive (OC) checkers have been shown to be impaired in memory. However, when encoding OC-related material, OC checkers exhibit superior recall. This study aims to investigate emotion-related memory performance in relation to checking using newly developed OC-specific material. Additionally, metacognitive characteristics such as cognitive confidence were considered.

METHOD

In a sample of 63 participants (including 26 participants with obsessive-compulsive disorder), immediate and delayed recall for neutral stories and for OC-specific stories containing checking- and washing-related content were assessed. Regression analyses were applied to investigate the relationship to checking symptoms. The influence of metacognitive characteristics on recall was also examined.

RESULTS

Higher checking was related to significantly better memory performance for a checking-related story as compared to two neutral stories. However, higher checking was also related to higher rates of forgetting of the OC-specific material over the delay period. Rates of forgetting in relation to checking were mediated by cognitive confidence. Diagnostic status was not predictive of any outcome variables.

LIMITATIONS

The use of typical and not idiosyncratic verbal material may limit the ecological validity of these findings.

CONCLUSIONS

In relation to high checking, different disorder-related cognitive and affective processes seem to interfere with memory encoding and retrieval at different stages. Metacognitive therapy methods might address these processes and thereby lead to a reduction of both cognitive impairment and OC symptoms.

Does "thinking about thinking" interfere with memory? An experimental memory study in obsessive-compulsive disorder

Neuropsychological assessments of participants with obsessive-compulsive disorder (OCD) indicate impaired verbal memory if to be remembered material has to be organized. People with OCD also tend to focus their attention on their thoughts (heightened cognitive self-consciousness). We tested the hypothesis that cognitive self-consciousness causes verbal memory deficits by provoking a division of attention between study task and thoughts. Thirty-six participants with OCD, 36 matched healthy controls and 36 participants with major depressive disorder (MDD) learned under proactive interference in three study conditions: single-task condition, condition with heightened cognitive self-consciousness and condition with an external secondary task. Memory was impaired in the cognitive self-consciousness condition compared to both other conditions. Independent of condition, participants with OCD showed a reduced memory performance compared to healthy controls, but did not differ from participants with MDD. Our results are in line with the hypothesis that cognitive self-consciousness causes memory impairment.

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.

Obsessive-compulsive tendencies are related to indecisiveness and reliance on feedback in a neutral color judgment task

BACKGROUND AND OBJECTIVES

The present study was designed to test whether OC tendencies are associated with indecisiveness and increased need for objective feedback in vague decision situations. This hypothesis was tested using a neutral color judgment task that places minimal demands on working memory.

METHODS

Sixty-one participants completed several measures of OC symptoms and tendencies. Indecisiveness was tested on a novel computerized task in which participants can move along a continuum marked by two colors at the extreme ends and are instructed to choose the color they judge to be the exact mid-point on the continuum.

RESULTS

OC scores were positively correlated with indecisiveness on the task, as assessed by the amount of time it took participants to complete the task and the extent of their search through the color continuum. This association was most pronounced when feedback for performance was not routinely provided. Requests for feedback were also positively correlated with OC scores. OC scores were not associated with actual performance on the task (accuracy levels) or with confidence ratings.

LIMITATIONS

The study relies on non-clinical participants and the extent to which these results would extend to OCD patients in unknown. Some effects may be confounded by the fixed order in which the task phases were administered.

CONCLUSIONS

The findings support the hypothesis that OC tendencies are associated with general indecisiveness and reliance on external feedback.

Neuropsychological function in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a chronic disease characterized by repetitive, unwanted intrusive thoughts and ritualistic behaviors. Studies of neuropsychological functions in OCD have documented deficits in several cognitive domains, particularly with regard to visuospatial abilities, executive functioning, and motor speed. The objective of the present study was to investigate systematically the cognitive functioning of OCD patients who were free of medication and comorbid psychiatric disorders. In the present study, 72 OCD patients were compared with 54 healthy controls on their performance in a comprehensive neuropsychological battery. The Yale-Brown Obsessive Compulsive Scale and the Hamilton Depression Rating Scale were administered to the patients, and a semistructured interview form was used to evaluate the demographic features of the patients and control subjects. Overall, widespread statistically significant differences were found in tests related to verbal memory, global attention and psychomotor speed, and visuospatial and executive functions indicating a poorer performance of the OCD group. A closer scrutiny of these results suggests that the OCD group has difficulty in using an effective learning strategy that might be partly explained by their insufficient mental flexibility and somewhat poor planning abilities.

Poor fine-motor and visuospatial skills predict persistence of pediatric-onset obsessive-compulsive disorder into adulthood

BACKGROUND

Half of pediatric-onset OCD cases remit by adulthood. Studies have demonstrated that initial response to pharmacotherapy, age of onset, prominent hoarding symptoms, and the presence of comorbid tic disorders are associated with long-term outcome. Our goal was to examine the association between childhood performance on neuropsychological testing and persistence of OCD into adulthood.

METHODS

Twenty-four children with OCD were followed for an average of 7.5 years into early adulthood. Neuropsychological performance in childhood (<16 years) was measured. The battery included the Wechsler Intelligence Scale for Children (WISC-III), the Purdue pegboard test, the Rey-Osterreith Complex Figure Task (RCFT) and the Beery-Buktenica test of Visual Motor Integration (VMI). We hypothesized that deficits in fine-motor skills, visuospatial skills, and nonverbal memory as well as overall intelligence would be associated with adulthood outcome. We used a Cox proportional hazard model of survival analysis in which time to remission of OCD symptoms was the main outcome variable.

RESULTS

Poor childhood performance on the Purdue pegboard task and the block design subscale of WISC-III was associated with persistence of OCD symptoms into adulthood. IQ, VMI, and nonverbal memory performance did not predict significantly the persistence of OCD.

CONCLUSIONS

These results suggest that visuospatial and fine-motor skill deficits are predictive of poor long-term outcome in pediatric-onset OCD. Future longitudinal studies are needed to chart the course of these deficits relative to the course of symptoms in OCD and to determine whether the association of these neuropsychiatric deficits with long-term outcome is specific to pediatric-onset OCD or generalizes to other psychiatric disorders.

Distinct neuropsychological profiles of three major symptom dimensions in obsessive-compulsive disorder

Recent neuroimaging studies have suggested that different symptom dimensions are mediated by partially distinct neural systems in obsessive-compulsive disorder (OCD). However, the correlations between neuropsychological profiles and symptom dimensions in OCD are unknown. The aim of this study was to examine the extent to which OCD symptom dimensions were associated with episodic memory and attention and executive functions. The symptom dimensions of 63 patients with OCD were assessed using both the Padua Inventory and the Y-BOCS symptom checklist. Then, we administered the Logical Memory (LM) subset of the Wechsler Memory Scale-Revised (WMR-R) test and evaluated inhibition (Stroop test, Trail Making test) and cognitive flexibility (Digit Symbol test, Letter Fluency, and Category Fluency). While associations were observed between scores on the contamination/cleaning dimension and better performances on the LM and Trail Making tests, associations were also observed between scores on the aggressive/checking dimension and poorer performances on the Trail Making test. In addition, we found that scores on the symmetry/ordering dimension were associated with poorer performances on the LM and Trail Making tests. Our results support the hypothesis that different symptoms may represent distinct and partially overlapping neurocognitive networks in OCD patients.

Cognitive dysfunction in post-traumatic obsessive-compulsive disorder

OBJECTIVE

To investigate whether patients who develop obsessive-compulsive disorder (OCD) after posttraumatic stress disorder, i.e. post-traumatic OCD (PsT-OCD), display a distinctive neurocognitive pattern of dysfunction.

METHODS

Patients with PsT-OCD (n = 16), pre-traumatic OCD (PrT-OCD) (n = 18), non-traumatic OCD (NonT-OCD) (n = 67) and healthy controls (n = 17) had their performance compared on the following neuropsychological tests: the Wisconsin Card Sorting Test, the Iowa Gambling Task, the Wechsler Memory Scale Logical Memory, the Brief Visual Memory Test - Revised, and the Wechsler Abbreviated Scale for Intelligence.

RESULTS

Patients with OCD, as a group, were characterized by poor set-shifting abilities and impaired verbal and visuospatial memories. Impaired set-shifting abilities were found to correlate with the severity of obsessive-compulsive symptoms in all groups of patients with OCD, with the exception of PsT-OCD. Only patients with PsT-OCD were characterized by impaired visuospatial recognition, which was found to correlate with poor set-shifting abilities in this particular group of patients, but not in individuals with other types of OCD or in healthy controls.

CONCLUSIONS

Our study suggests that PsT-OCD is associated with a distinctive pattern of neurocognitive dysfunction, thus providing support for a different subtype of OCD.

Remembering and forgetting: directed forgetting effect in obsessive-compulsive disorder

It has been reported that episodic memory seems to be impaired in patients with obsessive-compulsive disorder (OCD) because the patients repeat a specific checking behavior, but it is still unknown if OCD patients show memory impairments associated with their unique symptoms or not. To study episodic memory in OCD patients, we examined the directed forgetting effect. Patients with OCD and healthy control participants were given a list of 24 emotionally neutral everyday words (12 remember [R]-cued words and 12 forget [F]-cued words) under two conditions: List and Item. The results of our study showed that OCD patients recalled a number of F-cued words similar to that for controls and relatively fewer R-cued words than controls under both List and Item conditions. Consequently, the directed forgetting effect was smaller in OCD patients than controls. Our results demonstrated that both selective encoding and retrieval inhibition processes are impaired in OCD, and we suggest that recall of unfavorable items to be forgotten intruded into necessary items to be remembered. This impairment in episodic memory may partially account for some of the unique clinical symptoms of OCD.

Memory and strategic processing in first-degree relatives of obsessive compulsive patients

BACKGROUND

The same executive dysfunctions and alterations in neuroimaging tests (both functional and structural) have been found in obsessive-compulsive patients and their first-degree relatives. These neurobiological findings are considered to be intermediate markers of the disease. The aim of our study was to assess verbal and non-verbal memory in unaffected first-degree relatives, in order to determine whether these neuropsychological functions constitute a new cognitive marker for obsessive-compulsive disorder (OCD).

METHOD

Recall and use of organizational strategies in verbal and non-verbal memory tasks were measured in 25 obsessive-compulsive patients, 25 unaffected first-degree relatives and 25 healthy volunteers.

RESULTS

First-degree relatives and healthy volunteers did not show differences on most measures of verbal memory. However, during the recall and processing of non-verbal information, deficits were found in first-degree relatives and patients compared with healthy volunteers.

CONCLUSIONS

The presence of the same deficits in the execution of non-verbal memory tasks in OCD patients and unaffected first-degree relatives suggests the influence of certain genetic and/or familial factors on this cognitive function in OCD and supports the hypothesis that deficits in non-verbal memory tasks could be considered as cognitive markers of the disorder.

Metacognitive beliefs in obsessive-compulsive patients: a comparison with healthy and schizophrenia participants

INTRODUCTION

Distorted metacognitive beliefs are increasingly considered in theoretical models of obsessive-compulsive disorder (OCD). However, so far no consensus has emerged regarding the specific metacognitive profile of OCD.

METHODS

Participants with OCD (n=55), schizophrenia (n=39), and nonclinical controls (n=49) were assessed with the Metacognitions Questionnaire (MCQ-30).

RESULTS

Except for positive beliefs about worry, both patient samples exceeded nonclinical controls on all MCQ subscales. The MCQ "need to control thoughts" and "negative beliefs about uncontrollability and danger" subscales showed strong correlations with obsessions, and scores in the former scale were elevated in hallucinators. In contrast to several prior studies, "cognitive confidence" was related neither to core OCD nor to schizophrenia symptomatology.

CONCLUSIONS

Notwithstanding large pathogenetic differences between OCD and schizophrenia, findings suggest that obsessions and hallucinations may share a common metacognitive pathway. Need to control thoughts and dysfunctional beliefs about the malleability of worries may represent critical prerequisites for the two phenomena to emerge.

Evidence for specific cognitive deficits in visual information processing in patients with OCD compared to patients with unipolar depression

OBJECTIVE

Neuropsychological studies comparing cognitive performance in patients suffering from Obsessive-Compulsive Disorder (OCD) or Major Depressive Disorder (MDD) revealed deficits in the domains of verbal fluency and viso-motor speed/set shifting in both groups. Spatial working memory deficits, however, have been identified as specific markers of OCD. As yet, it has not been substantiated whether deficits in visual organization and complex visual memory are also specific to OCD and are not shared by MDD.

METHOD

Test performance in seven cognitive domains was assessed in 40 OCD patients, 20 MDD patients, and 40 healthy controls. Patient groups were matched according to severity of depressive symptoms.

RESULTS

Deficits shared by both patient groups, as compared to controls, were found in delayed spatial recall and verbal fluency while verbal memory was normal in both patient groups. Only patients with OCD, but not MDD patients were impaired in the domains visual memory, viso-motor speed/set shifting, visual organization, and problem solving. In addition, OCD patients differed significantly from MDD subjects in visual organization and problem solving. Visual organization scores correlated significantly with severity of current compulsions in the OCD group (r=-.324).

CONCLUSIONS

OCD patients demonstrate difficulties in visual organization and mental manipulation of complex visual material, which are not accounted for by depressive symptoms and which constitute a specific cognitive deficit of the disorder.

Brain potentials of conflict and error-likelihood following errorful and errorless learning in obsessive-compulsive disorder

BACKGROUND

The anterior cingulate cortex (ACC) is thought to be overacting in patients with Obsessive Compulsive Disorder (OCD) reflecting an enhanced action monitoring system. However, influences of conflict and error-likelihood have not been explored. Here, the error-related negativity (ERN) originating in ACC served as a measure of conflict and error-likelihood during memory recognition following different learning modes. Errorless learning prevents the generation of false memory candidates and has been shown to be superior to trial-and-error-learning. The latter, errorful learning, introduces false memory candidates which interfere with correct information in later recognition leading to enhanced conflict processing.

METHODOLOGY/PRINCIPAL FINDINGS

Sixteen OCD patients according to DSM-IV criteria and 16 closely matched healthy controls participated voluntarily in the event-related potential study. Both, OCD- and control group showed enhanced memory performance following errorless compared to errorful learning. Nevertheless, response-locked data showed clear modulations of the ERN amplitude. OCD patients compared to controls showed an increased error-likelihood effect after errorless learning. However, with increased conflict after errorful learning, OCD patients showed a reduced error-likelihood effect in contrast to controls who showed an increase.

CONCLUSION/SIGNIFICANCE

The increase of the errorlikelihood effect for OCD patients within low conflict situations (recognition after errorless learning) might be conceptualized as a hyperactive monitoring system. However, within high conflict situations (recognition after EF-learning) the opposite effect was observed: whereas the control group showed an increased error-likelihood effect, the OCD group showed a reduction of the error-likelihood effect based on altered ACC learning rates in response to errors. These findings support theoretical frameworks explaining differences in ACC activity on the basis of conflict and perceived error-likelihood as influenced by individual error learning rate.

Metacognition and episodic memory in obsessive-compulsive disorder

Memory deficits in patients with obsessive-compulsive disorder (OCD) have been frequently reported but are not sufficiently accounted for by cognitive models of OCD. The aim of the study was to identify cognitive mechanisms that might be able to explain memory deficits in OCD. We hypothesized that a self-conscious meta-cognitive style might be responsible for reduced memory performance in OCD. Episodic verbal memory performance was assessed in 23 participants with OCD (DSM-IV criteria) and 22 matched controls. Cognitive self-consciousness was assessed with a self-report measure derived from the Meta-Cognitions Questionnaire (MCQ). Compared to controls, OCD participants showed reduced immediate and delayed recall of complex verbal material and increased self-reported levels of cognitive self-consciousness. Multiple regression analyses indicated that group differences in story recall were significantly mediated by self-reported trait cognitive self-consciousness. Results point to the deteriorating effects of a thought-focused cognitive style on effortful encoding processes in OCD.

Comparable performance of patients with obsessive-compulsive disorder (OCD) and healthy controls for verbal and nonverbal memory accuracy and confidence: time to forget the forgetfulness hypothesis of OCD?

The memory deficit or forgetfulness hypothesis of obsessive-compulsive disorder (OCD) has received considerable attention and empirical effort over the past decades. The present study aimed to provide a fair test of its various formulations: (1) memory dysfunction in OCD is ubiquitous, that is, manifests irrespective of modality and material; (2) memory dysfunction is found for nonverbal but not verbal material, (3) memory dysfunction is secondary to executive impairment; and (4) memory dysfunction affects meta-memory rather than memory accuracy. Participants comprised 43 OCD patients and 46 healthy controls who were tested on the Picture Word Memory Test (PWMT), which provides several unconfounded parameters for nonverbal and verbal memory accuracy and confidence measures across different time-points. In addition, the Trail-Making Test B was administered to test assumption number 3. Replicating earlier work of our group, samples displayed similar performance on all indices. None of the different formulations of the memory deficit hypothesis were supported. In view of waning evidence for a global memory deficit in OCD, neuropsychological research on OCD should more thoroughly investigate moderators and triggers of occasional instances of impaired performance, particularly cognitive biases such as perfectionism and an inflated sense of responsibility.

No deficits in nonverbal memory, metamemory and internal as well as external source memory in obsessive-compulsive disorder (OCD)

A large body of literature suggests that some symptoms of obsessive-compulsive disorder (OCD) result from mnemonic dysfunctions. The present study tested various formulations of the memory deficit hypothesis considering important moderators, such as depression and response slowing. Thirty-two OCD patients and 32 healthy controls were presented verbal or nonverbal instructions for actions (e.g. simple gestures). These actions should either be performed or imagined. For recognition, previously presented as well as novel actions were displayed. Decisions had to be made whether an action was previously displayed (verbally vs. nonverbally) or not and whether an action was performed or imagined (internal source memory). Moreover, both judgments required confidence ratings. Groups did not differ in memory accuracy and metamemory for verbally presented material. Patients displayed some impairment for nonverbally presented material and imagined instructions, which, however, could be fully accounted for by response slowing and depressive symptoms. The study challenges the view that primary memory deficits underlie OCD or any of its subtypes. We claim that research should move forward from the mere study of objective impairment to the assessment of cognitive performance in conjunction with personality traits such as inflated responsibility.

Clinical correlates of word recognition memory in obsessive-compulsive disorder: an event-related potential study

Memory disturbances found in obsessive-compulsive disorder (OCD) may partially be related to dysfunction of cortico-subcortical circuits. However, it is still unknown how OCD symptomatology is related to memory processing. To explore this question, event-related potentials (ERPs) were recorded in a continuous word-recognition paradigm in OCD patients with either severe or moderate scores on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) (group S and group M, n=8 each) and in normal healthy controls (n=16). Typically ERPs to repeated items are characterized by more positive waveforms beginning approximately 250 ms post-stimulus. This "old/new effect" has been shown to be relevant for memory processing. The early old/new effect (ca. 300-500 ms) with a frontal distribution is proposed to be a neural correlate of familiarity-based recognition. The late old/new effect (post-500 ms) is assumed to reflect conscious memory retrieval processes. The OCD group S showed a normal early old/new effect and a reduced late old/new effect compared with group M and the control group, but no difference was found between group M and the control group. Source analyses for the late old/new effect showed statistically reduced cerebral activation in the anterior cingulate for OCD group S in contrast to the control group. Additionally, the early old/new effect in OCD group S was negatively correlated with the Y-BOCS total scores, and the late old/new effect was negatively correlated with obsession sub-scores. The severely, not moderately, ill OCD patients showed an impaired conscious recollection of the word-to-be-remembered, which suggested an impairment of working memory capacity in these patients due to a dysfunction in the frontal and cingulate cortex.

Motor inhibition in trichotillomania and obsessive-compulsive disorder

We investigated motor inhibition abilities in trichotillomania (TTM) and obsessive-compulsive disorder (OCD), two disorders characterized by repetitive, intentionally performed behaviors. Performance in a GoNogo experiment of 25 TTM and 21 OCD participants was compared to the performance of 26 HC participants. In contrast to OCD and HC participants, TTM participants tended to perform either 'fast and inaccurate' (indicating poor motor inhibition) or 'slow and accurate'. TTM participants with poor motor inhibition reported a significantly earlier age of TTM onset than those TTM participants who performed well. There was no evidence for motor inhibition deficits in OCD. Based on our data, a subgroup of TTM sufferers seems to be characterized by motor inhibition deficits.

Neurocognitive indices of executive hypercontrol in obsessive-compulsive disorder

OBJECTIVE

Cognitive impairment, more often involving memory and/or executive functions, has been reported in obsessive-compulsive (OC) patients. The present study aimed at: i) replicating, in an independent sample, previous findings by our group showing neurocognitive slowness limited to executive tasks; ii) assessing the influence of deficit in general cognitive abilities on executive dysfunction.

METHOD

A comprehensive neuropsychological battery was administered to 30 drug-free OC patients and 30 healthy controls.

RESULTS

Obsessive-compulsive patients performed worse on visuospatial tests, were slower on executive tasks, and performed worse on the Wisconsin Card Sorting Test. After covarying for Wechsler Adult Intelligence Scale-Revised performance Intellectual Quotient, a lesser degree of executive dysfunction was observed.

CONCLUSION

Obsessive-compulsive patients exhibit an impairment of executive functions, especially when tasks also require visuospatial abilities. The impairment might reflect a hyperactivity of the executive control.

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.

Effect of cognitive training focusing on organizational strategies in patients with obsessive-compulsive disorder

The purpose of the present paper was to develop a cognitive training program for patients with obsessive-compulsive disorder (OCD) and evaluate its effectiveness. Nine 60-min sessions focusing on the improvement of organizational strategies were given to 15 patients with OCD over a period of 5 weeks. The control group consisted of 15 age- and sex-matched patients also with OCD. The Rey-Osterrieth Complex Figure Test and Korean-California Verbal Learning Test were administered before and after cognitive training. Clinical symptoms were assessed with the Yale-Brown Obsessive-Compulsive Scale. The memory function in the treatment group improved and their clinical symptoms were alleviated after training, compared to those of the control group. Cognitive training of OCD patients not only improved their memory function, but also alleviated their clinical symptoms. Therefore, cognitive training, focusing on the improvement of organizational strategies, could be an effective treatment modality for patients with OCD.

Strategic memory in adults with anorexia nervosa: are there similarities to obsessive compulsive spectrum disorders?

OBJECTIVE

There is growing interest in the relationship between anorexia nervosa (AN) and obsessive-compulsive (OC) spectrum disorders (e.g., OCD, body dysmorphic disorder [BDD]). Previous neuropsychological investigations of OC spectrum disorders have identified problems with the efficient use of strategy on complex measures of learning and memory. This study evaluated nonverbal strategic memory in AN outpatients using an approach previously applied to OC spectrum disorders.

METHOD

Eighteen patients with AN and 19 healthy control participants completed the Rey-Osterrieth Complex Figure Test (RCFT), a widely used measure of nonverbal strategic planning, learning, and memory.

RESULTS

Individuals with AN differed significantly from healthy controls in the organizational strategies used to copy the RCFT figure, and they recalled significantly less information on both immediate and delayed testing. Multiple regression analyses indicated that group differences in learning were mediated by copy organizational strategies.

CONCLUSION

These results are identical to study findings in OCD and BDD, indicating important shared neuropsychological features among AN and these OC spectrum disorders. As in OCD and BDD, the essential cognitive deficit in AN was impaired use of organizational strategies, which may inform our understanding of the pathophysiology of AN and potentially offer treatment implications.

Visuospatial Abilities, Memory, and Executive Functioning in Trichotillomania and Obsessive-Compulsive Disorder

Few studies have compared neuropsychological functioning in trichotillomania (TTM) and obsessive-compulsive disorder (OCD). In OCD, most studies suggest abnormal visuospatial abilities, memory, and executive functioning. We compared 23 TTM, 21 OCD and 26 healthy control individuals on neuropsychological tasks assessing these abilities. Neither the TTM nor the OCD groups suffered from generalized neuropsychological deficits compared to the healthy control group. TTM participants showed increased perseveration on the Object Alternation Task suggesting difficulties with response flexibility. OCD participants showed impaired ability to learn from feedback on the Wisconsin Card Sorting Test. Other executive functions, as well as memory and visuospatial abilities were unimpaired in TTM and OCD. Our data suggest that TTM and OCD are characterized by different patterns of neuropsychological dysfunction.

A check on the memory deficit hypothesis of obsessive-compulsive checking

A number of recent studies have challenged the hypothesis that patients with obsessive-compulsive disorder (OCD) display global memory deficits. An alleviated form of the memory deficit hypothesis posits that OCD patients share deficits to vividly recall memory episodes. According to the latter view, checking rituals can be understood as counter-productive coping strategies to "enrich" memory episodes in order to make them more distinctive. A source memory task was administered to 27 OCD (17 checkers) and 51 healthy participants. Along with confidence judgments, a remember-know procedure was employed to assess whether OCD patients display problems with conscious/vivid recollection. Patients with or without checking compulsions did not exhibit differences to controls on source memory accuracy and meta-memory. Patients forgot more self-generated items, which, however, was related to comorbid depressive but not OCD symptoms. Findings challenge the ubiquity of memory deficits in OCD. To account for the inconclusive pattern of results in the literature, it is suggested that patients mistrust their memories and adopt checking rituals only when perceived responsibility is inflated.

Strategy implementation in obsessive-compulsive disorder and trichotillomania

BACKGROUND

The use of strategies to aid performance when undertaking neuropsychological tasks is dependent on intact fronto-striatal circuitry, and growing evidence suggests impaired spontaneous use of strategies in patients with obsessive-compulsive disorder (OCD). However, studies to date have not examined the effects of strategy training on task performance in OCD or in trichotillomania (compulsive hair-pulling, a condition that has been argued to share overlap with OCD in terms of phenomenology and co-morbidity).

METHOD

The ability to generate novel visuospatial sequences using a computer interface was examined before and after undertaking optimal strategy training in 20 OCD patients, 17 trichotillomania patients, and 20 controls (matched for age, education, and IQ).

RESULTS

OCD patients failed to improve ability to generate novel sequences above baseline despite successfully completing strategy training to the same extent as other groups. In contrast, performance of trichotillomania patients improved significantly after training to the same extent as controls. Groups did not differ on memory span, trial-by-trial action monitoring, or ability to generate novel visuospatial sequences prior to strategy training.

CONCLUSIONS

Strategy implementation deficits, suggestive of cognitive inflexibility and fronto-striatal dysfunction, appear integral to the neurocognitive profile of OCD but not trichotillomania. Future research should investigate cognitive flexibility in obsessive-compulsive spectrum disorders using a variety of paradigms, and clarify the contribution of specific neural structures and transmitter systems to deficits reported.

The contribution of metamemory deficits to schizophrenia

A number of recent studies have demonstrated that individuals with schizophrenia display knowledge corruption; that is, they hold false information with strong conviction. This aberration in metamemory is thought to stem from poor memory accuracy in conjunction with impaired discrimination of correct and incorrect judgments in terms of confidence. Thirty-one participants with schizophrenia, along with 61 healthy control participants and 48 control participants with other psychiatric conditions, participated in a computerized source memory task. Whereas no differences in memory accuracy were observed between the group with schizophrenia and the group with other psychiatric diagnoses, knowledge corruption was specifically impaired in those with schizophrenia. Schizophrenia participants showed a significantly decreased confidence gap: They were more confident in errors and less confident in correct responses relative to those in the control groups. Knowledge corruption is theorized to be a potential risk factor for the emergence of delusions.

Cognitive inhibition in trichotillomania and obsessive–compulsive disorder

Cognitive inhibition was investigated in 21 trichotillomania (TTM), 21 obsessive-compulsive disorder (OCD) and 26 healthy control (HC) participants using a block cued directed forgetting task. After encoding a word list, participants were instructed to intentionally FORGET these words and to REMEMBER another word list. Both lists included TTM-related and neutral (kitchen-related) words in equal proportions, with the TTM-related words generally of negative valence and the kitchen-related words generally of neutral valence for all participants. A superior free recall of REMEMBER versus FORGET words suggests intact cognitive inhibition. The performance of OCD participants indicated a specific deficit in inhibiting the retrieval of information with negative valence, which was not found in TTM. HC participants, in contrast to TTM and OCD participants, were rather inattentive to negative information. In conclusion, although attention was disproportionately directed towards negative information in both disorders, cognitive inhibition deficits appeared specific to OCD.

The neuropsychology of obsessive compulsive disorder: the importance of failures in cognitive and behavioural inhibition as candidate endophenotypic markers

Obsessive compulsive disorder (OCD) is a highly debilitating neuropsychiatric condition with estimated lifetime prevalence of 2-3%, more than twice that of schizophrenia. However, in contrast to other neuropsychiatric conditions of a comparable or lesser prevalence, relatively little is understood about the aetiology, neural substrates and cognitive profile of OCD. Despite strong evidence for OCD being familial, with risk to first-degree relatives much greater than for the background population, its genetic underpinnings have not yet been adequately delineated. Although cognitive dysfunction is evident in the everyday behaviour of OCD sufferers and is central to contemporary psychological models, theory-based studies of neurocognitive function have yet to reveal a reliable cognitive signature, and interpretation has often been confounded by failures to control for co-morbidities. The neuroimaging findings in OCD are amongst the most robust reported in the psychiatric literature, with structural and functional abnormalities frequently reported in orbitofrontal cortex, anterior cingulate cortex, and caudate nucleus. In spite of this, our relative lack of understanding of OCD neurochemical processes continues to impede progress in the development of novel pharmacological treatment approaches. Integrating the neurobiological, cognitive, and clinical findings, we propose that OCD might usefully be conceptualised in terms of lateral orbitofrontal loop dysfunction, and that failures in cognitive and behavioural inhibitory processes appear to underlie many of the symptoms and neurocognitive findings. We highlight existing limitations in the literature, and the potential utility of endophenotypes in overcoming these limitations. We propose that neurocognitive indices of inhibitory functions may represent a useful heuristic in the search for endophenotypes in OCD. This has direct implications not only for OCD but also for putative obsessive-compulsive spectrum conditions including attention deficit hyperactivity disorder, Tourette's syndrome, and trichotillomania (compulsive hair pulling).

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.