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

Cognitive impairment in hoarding disorder: a systematic review

OBJECTIVE

In the present study, we aimed to perform a systematic review evaluating the cognitive performance of patients with hoarding disorder (HD) compared with controls. We hypothesized that HD patients would present greater cognitive impairment than controls.

METHODS

A systematic search of the literature using the electronic databases MEDLINE, SCOPUS, and LILACS was conducted on May 2020, with no date limit. The search terms were "hoarding disorder," "cognition," "neuropsychology," "cognitive impairment," and "cognitive deficit." We included original studies assessing cognitive functioning in patients with HD.

RESULTS

We retrieved 197 studies initially. Of those, 22 studies were included in the present study. We evaluated 1757 patients who were 41 to 72 years old. All selected studies comprised case-control studies and presented fair quality. Contrary to our hypothesis, HD patients showed impairment only in categorization skills in comparison with controls, particularly at confidence to complete categorization tasks. Regarding attention, episodic memory, working memory, information-processing speed, planning, decision-making, inhibitory control, mental flexibility, language, and visuospatial ability, HD patients did not show impairment when compared with controls. There is a paucity of studies on social cognition in HD patients, although they may show deficits. The impact of emotion in cognition is also understudied in HD patients.

CONCLUSION

Except for categorization skills, the cognitive performance in HD patients does not seem to be impaired when compared with that in controls. Further work is needed to explore social cognition and the impact of emotion in cognitive performance in HD patients.

A cross-species assessment of behavioral flexibility in compulsive disorders

Lack of behavioral flexibility has been proposed as one underlying cause of compulsions, defined as repetitive behaviors performed through rigid rituals. However, experimental evidence has proven inconsistent across human and animal models of compulsive-like behavior. In the present study, applying a similarly-designed reversal learning task in two different species, which share a common symptom of compulsivity (human OCD patients and Sapap3 KO mice), we found no consistent link between compulsive behaviors and lack of behavioral flexibility. However, we showed that a distinct subgroup of compulsive individuals of both species exhibit a behavioral flexibility deficit in reversal learning. This deficit was not due to perseverative, rigid behaviors as commonly hypothesized, but rather due to an increase in response lability. These cross-species results highlight the necessity to consider the heterogeneity of cognitive deficits in compulsive disorders and call for reconsidering the role of behavioral flexibility in the aetiology of compulsive behaviors.

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.

Cognitive performance in children and adolescents at high-risk for obsessive-compulsive disorder

BACKGROUND

Cognitive performance has been studied in adults with obsessive-compulsive symptoms (OCS) and in adult relatives of patients with obsessive-compulsive disorder (OCD) Meanwhile, few studies have been conducted with children under the same conditions. This study compared the neurocognitive domains previously associated with dysfunction in OCD, especially visuoconstructive ability, visuospatial memory, executive functions, and intelligence, in children and adolescents at high risk (HR) for OCD (n = 18) and non-OCD controls (NOC) (n = 31).

METHODS

For the HR group, we considered the first-degree relatives of patients with OCD that present OCS, but do not meet diagnostic criteria for OCD. Psychiatric diagnosis was assessed by experienced clinicians using the Structured Clinical Interview for DSM-IV and OCS severity was measured by the Yale-Brown Obsessive-Compulsive Scale. Neurocognitive assessment was performed with a comprehensive neuropsychological battery. Performance on the cognitive domains was compared between groups using Multivariate Analysis of Variance, whereas performance on the neuropsychological variables was compared between groups using independent t-tests in a cognitive subdomain analysis.

RESULTS

The cognitive domain analysis revealed a trend towards significance for impairments in the motor and processing speed domain (p = 0.019; F = 3.12) in the HR group. Moreover, the cognitive subdomain analysis identified a statistically significant underperformance in spatial working memory in the HR group when compared to the NOC group (p = 0.005; t = - 2.94), and a trend towards significance for impairments in non-verbal memory and visuoconstructive tasks in the HR group.

CONCLUSIONS

Our results suggest impairments in spatial working memory and motor and processing speed in a non-clinical sample of HR participants. Considering the preliminary nature of our findings, further studies investigating these neurocognitive domains as potential predictors of pediatric OCD are warranted.

Neuropsychological performance across symptom dimensions of obsessive-compulsive disorder: a comment on the state and critical review of the literature

Introduction: Obsessive-compulsive disorder (OCD) is a heterogeneous disorder, with multiple symptom presentations. Delineating the neuropsychological characteristics associated with previously identified symptom clusters may therefore be useful in assisting to better define symptom subtypes of OCD.Areas covered: This review summarizes the existing literature on the assessment of neuropsychological performance in symptom-based dimensions of OCD. Results of 23 studies are described and the methodological issues and challenges present in this body of literature are discussed.Expert opinion: The current state of the literature precludes a meaningful meta-analysis of cognitive dysfunction across the breadth of symptom dimensions of OCD. This is due primarily to significant methodological differences observed between studies, both in terms of neuropsychological measures and symptom subtyping methods employed, and any resulting meta-analytic results would be biased by varying quality of evidence. Future studies addressing these limitations should include more consistent neuropsychology measures and methods of classifying OCD symptoms with the aim of reproducing the results of previous research to identify more concrete patterns of neuropsychological performance across dimensions; best practices and alternative approaches are discussed.

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.

White matter alterations associate with onset symptom dimension in obsessive-compulsive disorder

AIM

The high heterogeneity of obsessive-compulsive disorder (OCD) is best described by a multidimensional model involving symptom dimensions. We aimed to investigate white matter alterations associated with OCD, focusing on the impact of long-lasting effect of symptom dimensions assessed at onset of illness. Furthermore, we investigated white matter alterations associated with this disorder, controlling for the impact of medications and for the prevailing current symptom dimension.

METHODS

We studied 58 patients affected by OCD and 58 age- and sex-matched healthy controls. We divided patients according to symptom dimension at onset of illness, assessed with the five-factor model. T-tests were performed in order to investigate differences between subgroups. Similar analyses were performed considering the prevailing current symptom dimension. Analyses were conducted with tract-based spatial statistics on diffusion tensor imaging.

RESULTS

Doubt/checking and rituals/superstition symptom dimensions at onset and symmetry/perfectionism current symptom dimensions were characterized by significant alterations in diffusion tensor imaging measures. An association of white matter alterations and symmetry/perfectionism current dimension was found only when controlling for the effect of doubt/checking dimension at onset. Finally, results pointed out that the observed differences between patients and healthy controls were carried by the effect of previous and current medications.

CONCLUSION

Our findings evidenced that onset symptom dimensions are associated with enduring alterations of white matter microstructure. Onset symptom dimensions may reflect underlying endophenotypes. In addition, present results confirm the effect of medications on white matter in OCD, showing a large effect of current treatment on myelination.

Clinical features associated with increased severity of illness in tertiary clinic referred patients with obsessive compulsive disorder

OBJECTIVE

Obsessive-compulsive disorder (OCD) is a prevalent and disabling condition. Specific patterns of psychiatric comorbidity, early age at onset, long duration of illness (DI) and untreated illness (DUI) have been associated with poor outcome in OCD. The present study was aimed to explore sociodemographic and clinical characteristics associated with increased severity of illness in a sample of OCD patients.

METHODS

A total of 124 OCD outpatients were recruited and divided into two groups on the basis of their severity of illness, as assessed through the Yale-Brown Obsessive Compulsive Scale (>24). Chi-squared test and t-test for independent samples were performed to compare sociodemographic and clinical variables between the two groups.

RESULTS

The group with increased severity of illness had a younger age, an earlier age at onset and age at first pharmacological treatment (p < .05). In addition, the same group showed a longer DI but a shorter DUI (p < .01). Moreover, significantly higher rates of psychiatric comorbidities (p < .01) were observed in the higher severity group.

CONCLUSIONS

Earlier age, age at onset and age at first pharmacological treatment, longer DI, shorter DUI and higher rate of psychiatric comorbidities were associated with increased severity of OCD. Further studies on larger samples are warranted to confirm the reported results.

Cognitive Dysfunction in Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a mental disorder featuring obsessions (intrusive thoughts) and compulsions (repetitive behaviors performed in the context of rigid rituals). There is strong evidence for a neurobiological basis of this disorder, involving limbic cortical regions and related basal ganglion areas. However, more research is needed to lift the veil on the precise nature of that involvement and the way it drives the clinical expression of OCD. Altered cognitive functions may underlie the symptoms and thus draw a link between the clinical expression of the disorder and its neurobiological etiology. Our extensive review demonstrates that OCD patients do present a broad range of neuropsychological dysfunctions across all cognitive domains (memory, attention, flexibility, inhibition, verbal fluency, planning, decision-making), but some methodological issues temper this observation. Thus, future research should have a more integrative approach to cognitive functioning, gathering contributions of both experimental psychology and more fundamental neurosciences.

Utility of Boston Qualitative Scoring System for Rey-Osterrieth Complex Figure: evidence from a Parkinson's Diseases sample

This study examined the ability of the Boston Qualitative Scoring System (BQSS) in comparison to the Osterrieth scoring method to separate Parkinson's Disease patients without dementia from healthy controls at the Rey-Osterrieth Complex Figure (ROCF) copy. 30 PD participants and 30 healthy participants completed ROCF copy. The performance was scored according to both methods. The results indicated that PD patients performed significantly worse on ROCF. According to ROC analyses, BQSS Copy Total score represented the most suitable index to distinguish between the two groups: a score below or equal to 16 indicates an impaired performance. Moreover, PD participants reported lower performance in the BQSS scores of Planning and Neatness. PD patients' poor performance in ROCF copy was related to executive difficulties, specifically in terms of planning and impulsivity, instead of global visuo-constructional impairments. An extensive evaluation of copy drawings allowing to disentangle between different involved cognitive domains would be suitable, specifically in those clinical conditions like PD, in which motor impairments affect drawing performance.

Scrupulosity and contamination OCD are not associated with deficits in response inhibition

BACKGROUND AND OBJECTIVES

Prior research has indicated a number of neuropsychological deficits in patients with OCD consistent with the cortico-striato-thalamo-cortical model of the disorder. Response inhibition (RI), defined as the inability to inhibit a prepotent response, has been identified as a possible candidate endophenotype for OCD. However, the results from previous studies of RI in OCD patients have been mixed, suggesting the possibility that some OCD dimensions may be associated with deficits in RI while others may not. The present study aimed to examine RI using a Go/No-Go (GNG) task in two OCD symptom dimensions, one of which, scrupulosity, has never been subject to neuropsychological investigation.

METHODS

A total of 63 individuals, consisting of scrupulous OCD (n = 26), contamination OCD (n = 18) and non-psychiatric controls (n = 19) completed study measures. Controlling for depression symptoms, no significant performance differences were found between the groups on the GNG test, indicating no deficits in RI among contamination or scrupulous OCD.

RESULTS

Results are consistent with several prior studies of RI in OCD that found no differences as compared to non-psychiatric controls, especially on GNG tests, and with more recent suggestions that RI may not constitute a clinical significant impaired domain in OCD.

LIMITATIONS

Limitations included a primarily highly educated and Caucasian sample.

CONCLUSIONS

Additional conclusions include careful consideration of the RI measures selected for future studies, as well as the need for further investigation into the neuropsychological and neurobiological nature of scrupulous OCD.

Neurocognitive performance in unmedicated patients with hoarding disorder

OBJECTIVE

Hoarding disorder (HD) is an often incapacitating psychiatric illness associated with a wide range of neurocognitive abnormalities. Some prior neuropsychological studies have found executive dysfunction in HD, but no clear pattern has emerged. One potential reason for discrepant results in previous studies might be the inclusion of patients on psychotropic and other medications that can affect neurocognitive performance. Therefore, we examined neurocognitive functioning in medication-free HD patients. We also added a novel investigation of implicit learning, which has been found to be abnormal in obsessive-compulsive disorder (OCD) and related disorders.

METHOD

Twenty-six participants meeting the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013) diagnostic criteria for HD and 23 normal controls were administered a battery of neuropsychological tests and symptom rating scales. All participants were free of psychotropic medications for at least 6 weeks prior to the study.

RESULTS

HD participants showed no significant differences from normal controls on measures of verbal memory, attention, or executive functioning, including response inhibition, planning, organization, and decision making. However, HD participants demonstrated a trend toward less implicit learning and greater use of explicit learning strategies during perceptual categorization compared to normal controls. HD participants who used an implicit strategy performed significantly worse than controls who used an implicit strategy. Hoarding symptom severity was not associated with neurocognitive performance.

CONCLUSIONS

HD patients may have a tendency to use explicit rather than implicit learning strategies for perceptual categorization but perform as well as normal controls on many other neurocognitive measures. Future studies should assess unmedicated participants and examine test strategies, not just outcomes.

Employing executive functions of perceptual and memory abilities in underweight and weight-restored anorexia nervosa patients

PURPOSE

Executive functions (EF) have been widely investigated in anorexia nervosa (AN) revealing difficulties in various aspects. We aimed at testing the effects of EF on stimuli perception and its representations in memory.

METHODS

Thirty AN underweight patients, 30 weight-restored AN patients, and 44 control participants, were recruited. Various EF were assessed using the Rey-Osterrieth Complex Figure Test, analyzed with the Boston Qualitative Scoring System.

RESULTS

No differences were found in visuo-constructional measures in either AN groups compared to controls on the copy and memory stages. However, both groups performed significantly worse than controls on most EF variables in the copy stage, while in the immediate and delayed memory stages the difference was less substantial.

CONCLUSIONS

Difficulties in EF among AN patients, current and weight restored, are more pronounced in the perceptual module and less so when employed through memory retrieval. The pattern, which is apparent after weight gain, suggests that there is no ameliorative effect on these difficulties.

Neuropsychological performance across symptom dimensions in pediatric obsessive compulsive disorder

BACKGROUND

Few studies have examined neuropsychological functioning among youth with obsessive compulsive disorder (OCD), with inconclusive results. Although methodological differences may contribute to inconsistent findings, clinical factors may also account for differential performance. Symptom dimensions are associated with specific patterns of genetic transmission, comorbidity, and treatment outcome, and may also be uniquely associated with neuropsychological performance. This study examined differences in cognitive sequelae and neurocognitive impairment across symptom dimensions among youth with OCD.

METHOD

Participants included 93 treatment-seeking youth diagnosed with OCD. A trained clinician administered the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) to parents and children together. Afterward, youth completed a battery of neuropsychological tests that assessed nonverbal memory and fluency, verbal memory, verbal fluency, verbal learning, processing speed, and inhibition/switching.

RESULTS

Across five symptom dimensions, youth exhibiting Hoarding symptoms (χ(2) = 5.21, P = .02) and Symmetry/Ordering symptoms had a greater occurrence of cognitive sequelae (χ(2) = 4.86, P = .03). Additionally, youth with Symmetry/Ordering symptoms had a greater magnitude of cognitive impairment (Mann-Whitney U = 442.50, Z = -2.49, P < .02), with specific deficits identified on nonverbal fluency (P < .01), processing speed (P < .01), and inhibition and switching (P < .02).

CONCLUSIONS

Neuropsychological deficits identified in youth with Hoarding and Symmetry/Ordering symptoms may suggest that these symptoms have characteristics specific to neurocognitive impairment. Alternatively, symptoms associated with these dimensions may impede youth's performance during testing. Findings advise neuropsychological testing for youth with symptoms on either of these dimensions when concerns about neuropsychological and/or academic impairment are present.

The neurobiological link between OCD and ADHD

Obsessive compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD) are two of the most common neuropsychiatric diseases in paediatric populations. The high comorbidity of ADHD and OCD with each other, especially of ADHD in paediatric OCD, is well described. OCD and ADHD often follow a chronic course with persistent rates of at least 40–50 %. Family studies showed high heritability in ADHD and OCD, and some genetic findings showed similar variants for both disorders of the same pathogenetic mechanisms, whereas other genetic findings may differentiate between ADHD and OCD. Neuropsychological and neuroimaging studies suggest that partly similar executive functions are affected in both disorders. The deficits in the corresponding brain networks may be responsible for the perseverative, compulsive symptoms in OCD but also for the disinhibited and impulsive symptoms characterizing ADHD. This article reviews the current literature of neuroimaging, neurochemical circuitry, neuropsychological and genetic findings considering similarities as well as differences between OCD and ADHD.

Compulsive hoarders: how do they differ from individuals with obsessive compulsive disorder?

Hoarding has been considered a subtype of obsessive-compulsive disorder (OCD). Planned revisions to the diagnostic criteria propose that hoarding form a separate diagnosis in a larger category of obsessive compulsive related disorders. To date, there have been few direct comparisons between hoarding and those with other symptoms of OCD. This study builds on work that suggests compulsive hoarding, while similar to OCD, comprises a clinically distinct condition. Three groups were compared: those with OCD without compulsive hoarding symptoms (n=102), those with compulsive hoarding but not OCD (n=21), and individuals who satisfied both criteria (n=25). The groups were compared on obsessionality, compulsivity, overvalued ideas, depression, and anxiety. The two hoarding groups were also compared on hoarding symptoms and savings cognitions. Results indicated that the hoarding-only group reported fewer symptoms than both OCD groups, including fewer obsessions and compulsions and lower depression. Both hoarding groups showed significantly higher overvalued ideas when compared to the OCD-only group. These results suggest that hoarders experience less subjective distress than those with OCD, yet have greater difficulty in challenging dysfunctional cognitions associated with the presenting condition. These findings suggest that individuals with hoarding, whether with or without OCD, will show greater difficulty engaging in cognitive-behavioral interventions.

The effect of practice on the recall of salient information in obsessive-compulsive disorder

Deficits in memory and cognitive inhibition have been proposed as underlying mechanisms of obsessive-compulsive disorder (OCD). To test this hypothesis, an emotional variant of the retrieval-induced forgetting (RIF) paradigm was constructed which investigates whether repeated retrieval of previously learned material (Rp+) leads to enhanced forgetting of related but nonretrieved material (Rp-) in comparison to unrelated material (NRp). Paradigm (involving OCD-relevant, neutral and negative material) was presented to 21 participants with OCD and 22 healthy controls. To compare personally relevant stimuli across groups, salience ratings of the material were included. RIF was not reduced in OCD per se. Tentative evidence was found for a weakened RIF effect for personally salient OCD-relevant material in OCD patients in comparison to healthy controls.

An exploration of economic reasoning in hoarding disorder patients

Current models of hoarding disorder (HD) emphasize problems of decision-making. Evidence for neuropsychological impairment in HD, however, has been mixed. The present study examined whether HD patients show problems of economic reasoning that could be associated with decision-making problems. Forty-two HD patients, 29 obsessive-compulsive disorder (OCD) patients, and 36 healthy control participants completed the Iowa gambling task (IGT), a computerized card playing game that assesses participants' ability to learn and utilize a rule of sacrificing short-term gain for long-term gain, and a cognitive dissonance reduction task that measured changes in preference for items (art prints) after selecting or rejecting them. Results showed no deficits on the IGT for HD participants, and no difference in dissonance reduction results after selecting or rejecting items on the dissonance reduction task. Furthermore, performance on these two tasks was unrelated to hoarding symptom severity or self-reported indecisiveness. It is suggested that the problems of cognitive processing in HD patients may be largely related to as-yet understudied processes, including idiosyncratic categorization problems for personally-owned items as well as other aspects of economic reasoning.

Neuropsychological functioning in hoarding disorder

Hoarding disorder (HD) is increasingly viewed as distinct from obsessive-compulsive disorder (OCD). In particular, some researchers have suggested that HD is characterized by substantial problems of neurocognitive function; however, HD patients have not yet been compared to OCD patients in this respect. The aim of the present study was to compare neuropsychological test performance in HD patients (n=27), OCD patients (n=12), and healthy controls (n=26). Consistent with previous research, HD patients showed an attenuated ability to sustain attention and poorer employment of adaptive memory strategies compared to healthy controls. HD and OCD patients did not differ significantly on these measures, although moderate effect sizes suggested that hoarders showed somewhat greater attenuation of attentional capacity. Rates of true impairment on any particular neuropsychological test were fairly low across all three groups, although 67% of HD patients (compared to 58% of OCD patients and 42% of healthy controls) scored in the impaired range on at least one measure (odds ratio=2.22). Results are discussed in terms of emerging conceptualizations of HD as a distinct illness.