Neurocognitive correlates of child obsessive compulsive disorder and Tourette syndrome

This study investigated the neurocognitive correlates of childhood OCD and TS, which are purported to share frontal-striatal dysfunction. Neurocognitive measures tapping frontal-striatal functions such as executive, attention/memory, and visuomotor abilities were administered to three groups of participants, OCD without comorbid TS (OCD), TS without comorbid OCD (TS), and normal controls. Results suggested that OCD group demonstrated deficits in the area of spatial attention relative to healthy controls. The OCD participants demonstrated no cognitive deficits compared to the TS group. TS participants showed trends towards impairments in the areas of response inhibition, divided attention, and cognitive flexibility relative to the OCD and normal control groups. Spatial attention deficits for the OCD group are partially consistent with adult OCD studies indicating deficits in spatial memory. TS findings were less robust and may be construed tentatively as suggestive of executive function deficits. Future research is needed to delineate the influence of development on neurocognitive deficits associated with OCD and TS.     

Cognitive and affective empathy in depression linked to executive control

Depression has been linked to executive dysfunction and emotion recognition impairments, associated with abnormalities in fronto-temporal and subcortical brain regions. Little is known about changes of different empathy subcomponents during depression, with potential impairments being related to the interpersonal difficulties of depressed patients. Twenty patients treated for an episode of unipolar depression and 20 matched healthy controls were assessed. Measures of dispositional and behavioural empathy components were administered along with tests of cognitive flexibility, response inhibition and working memory. Relative to controls, depressed patients showed higher self-reported dispositional empathy scores, mainly driven by increased personal distress scores. Patients and controls did not differ significantly in terms of behavioural cognitive empathy, empathic concern and personal affective involvement or in their executive function performance. In the patients, cognitive flexibility and response inhibition accuracy were associated with behavioural empathy. While an increased disposition towards feeling personal distress in response to other people's suffering seems to be in generally related to depressive symptoms, behavioural empathy might depend on the functional integrity of executive control during an episode of clinical depression. Impairments in this regard could contribute to the interpersonal difficulties depressed patients are frequently faced with which might have important implications for treatment.     

Dimensions of intelligence in schizophrenia: evidence from patients with preserved, deteriorated and compromised intellect

There is a growing literature describing a subgroup of "high-functioning" people with schizophrenia who show preserved intellectual ability (IQ). A detailed characterisation of the cognitive abilities of this group may be important in targeting appropriate treatment, management and services for patients with schizophrenia. It is a widely held belief that variation in cognitive processing speed is the basis of individual differences in intelligence. The main objective of this study was to identify subgroups of schizophrenia patients with preserved (N=45), deteriorated (N=47) and compromised (N=17) intellect in order to study whether these subgroups differ in specific cognitive abilities (e.g. executive functions) or in general cognitive processing speed, as measured with an inspection time (IT) task. The patients who displayed an average estimated premorbid IQ, with no evidence of IQ decline (premorbid-current IQ difference <10 points), were found to show better performance on measures of executive function (continuous performance task, verbal fluency) compared with patients in the deteriorated and compromised subgroups. Nevertheless, this represented significantly impaired performance relative to healthy controls. In contrast, the average inspection times of patients with preserved IQ were as slow as those obtained in the deteriorated or compromised groups, indicating that high functioning patients are impaired in terms of cognitive processing speed. Furthermore, the average IT for all schizophrenia groups was significantly slower than that of healthy controls. These findings suggest that high functioning patients with schizophrenia exhibit enduring cognitive difficulties that may impact on their ability to benefit from rehabilitation interventions.     

Alterations in neural systems mediating cognitive flexibility and inhibition in mood disorders

Impairment in mental flexibility may be a key component contributing to cardinal cognitive symptoms among mood disorders patients, particularly thought control disorders. Impaired ability to switch from one thought to another might reflect difficulties in either generating new mental states, inhibiting previous states, or both. However, the neural underpinnings of impaired cognitive flexibility in mood disorders remain largely unresolved. We compared a group of mood disorders patients (n = 29) and a group of matched healthy subjects (n = 32) on a novel task‐switching paradigm involving happy and sad faces, that allowed us to separate generation of a new mental set (Switch Cost) and inhibition of the previous set during switching (Inhibition Cost), using fMRI. Behavioral data showed a larger Switch Cost in patients relative to controls, but the average Inhibition Cost did not differ between groups. At the neural level, a main effect of group was found with stronger activation of the subgenual cingulate cortex in patients. The larger Switch Cost in patients was reflected by a stronger recruitment of brain regions involved in attention and executive control, including the left intraparietal sulcus, precuneus, left inferior fontal gyrus, and right anterior cingulate. Critically, activity in the subgenual cingulate cortex was not downregulated by inhibition in patients relative to controls. In conclusion, mood disorder patients have exaggerated Switch Cost relative to controls, and this deficit in cognitive flexibility is associated with increased activation of the fronto‐parietal attention networks, combined with impaired modulation of the subgenual cingulate cortex when inhibition of previous mental states is needed. Hum Brain Mapp 37:1335‐1348, 2016. © 2016 Wiley Periodicals, Inc.     

Association of symptoms and executive function in schizophrenia and bipolar disorder

The extent to which cognitive impairment in psychosis is related to the particular disorder or the pattern of symptoms is unclear. We examined executive function in two groups of schizophrenia patients with predominant symptoms of disorganisation (n=15) and psychomotor poverty (n=15), respectively, two groups of bipolar I disorder patients with predominant symptoms of mania (n=15) and depression (n=15), respectively, and 30 healthy controls. We predicted that the pattern of symptoms ('excess' [disorganisation/mania] or 'deficiency' [negative symptoms/depression]) would be more related to executive ability than the underlying disorder. The patient groups showed partially overlapping executive dysfunctions relative to the control group. There were no significant differences between groups with 'excess' symptoms (schizophrenia patients with thought disorder and bipolar patients with mania), or between groups with 'deficiency' symptoms (schizophrenia patients with negative symptoms and bipolar patients with depression). In contrast, differences were noted between groups with the same diagnosis: Schizophrenia patients with disorganisation were less accurate in semantic verbal fluency than those with negative symptoms; and bipolar patients with mania tended to be faster, but less accurate, in sentence completion than those with depression. A statistical comparison of the associations of 'diagnosis' and the 'excess-deficiency' dimension with executive function revealed a trend for a greater association of the latter with two measures of performance accuracy. Executive dysfunction in patients with psychotic disorders may be more related to their symptom profile than their diagnosis.     

Executive Function in Problem Gamblers with and without History of Depression

Executive function deficits are well-documented in gambling disorder as well as major depressive disorder. The literature also demonstrates that these clinical problems are highly comorbid. Despite the high rates of comorbidity and the transdiagnostic nature of executive function deficits, few studies have explored executive function in gamblers with a history of depression. As a preliminary investigation, the current work characterized executive function in a sample of problem gamblers with a history of depression (N = 19), problem gamblers without a history of depression (N = 19), and healthy controls (N = 40). Consistent with predictions, both gambler groups showed deficits in planning relative to controls. However, contrary to predictions, gamblers with a history of depression performed better than gamblers without a history of depression on a measure of cognitive flexibility. Results reveal that examining differences in executive function among different subtypes of problem gamblers may be a promising area for future study.     

Neuropsychological function in obsessive-compulsive disorder: effects of comorbid conditions on task performance.

BACKGROUND: Neuropsychological testing reveals a pattern of impairment among patients with obsessive-compulsive disorder (OCD) which implicates the orbitofrontal region. Studies of neuropsychological function in OCD differ regarding performance deficits on classical tests of frontal executive function. In some studies, OCD patients did not demonstrate impaired performance on tests of executive function. However, other researchers have documented performance deficits among OCD patients on measures of executive function. Patients with OCD also exhibit performance deficits on tests of visual/spatial memory and verbal memory. Again, in some studies, OCD patients did not demonstrate impaired performance on tests of memory function. How can we account for the conflicting findings? One possibility is that performance deficits on tests of cognitive function are associated with comorbid conditions. In prior work, we observed that OCD patients who did poorly on executive function tasks obtained high scores on a measure of schizotypal personality. A second possibility is that executive function deficits among patients with OCD are associated with comorbid depressive symptoms. METHOD: In the present study, a comprehensive neuropsychological test battery was administered to patients with OCD and matched healthy control subjects. We also administered dimensional measures of schizotypal personality and depression to patients with OCD and controls. We conducted analyses of covariance (ANCOVA), with scores on measures of schizotypal personality and depression used as covariates. RESULTS: OCD patients demonstrated performance deficits on measures of delayed memory, response inhibition, alternation learning, and obtained significantly higher scores on measures of disinhibition, impulsivity, and temporolimbic symptoms; however, OCD patients did not exhibit impaired performance on tests of executive function and verbal fluency, and did not report a significantly greater number of dysexecutive symptoms, when coexistent depressive and schizotypal symptoms were taken into account. CONCLUSION: Findings are consistent with the contention that dysfunction of an orbitofrontal-limbic network underlies OCD.     

Prefrontal-Thalamic Anatomical Connectivity and Executive Cognitive Function in Schizophrenia

Background

Executive cognitive functions, including working memory, cognitive flexibility, and inhibition, are impaired in schizophrenia. Executive functions rely on coordinated information processing between the prefrontal cortex (PFC) and thalamus, particularly the mediodorsal nucleus. This raises the possibility that anatomical connectivity between the PFC and mediodorsal thalamus may be 1) reduced in schizophrenia and 2) related to deficits in executive function. The current investigation tested these hypotheses.

Building a neurocognitive profile of thought disorder in schizophrenia using a standardized test battery

A core symptom of schizophrenia is thought disorder (TD). The cognitive abilities of semantic processing and executive function are argued to be etiologically linked to TD. However, there has been no comprehensive investigation of neurocognition in TD to date. The neurocognitive profile of 58 schizophrenia patients and 48 healthy controls was examined using the MATRICS Consensus Cognitive Battery and the D-KEFS Color–Word Interference Test. TD patients performed more poorly than non-TD patients on the cognitive domains of Verbal Learning and Inhibition, reflective of semantic and executive function respectively, confirming their critical roles over and above other cognitive deficits in schizophrenia.     

Cognitive dysfunctions and white matter lesions in patients with bipolar disorder in remission

OBJECTIVE: To compare cognitive functioning in relation to white matter lesions in bipolar disorder in remission and schizophrenia. METHOD: Cognitive performance and the occurrence of white matter lesions on MRI images of the brain were assessed in 22 patients with bipolar disorder in remission, 22 patients with schizophrenia and 22 healthy volunteers. RESULTS: Performance of tests of memory, speed and cognitive flexibility was significantly impaired in both patient groups. The frequency of white matter lesions did not differ significantly between the three groups. No differences in cognitive performance were found between patients with white matter lesions and patients without such lesions. CONCLUSION: White matter lesions apparently do not underlie cognitive deficits that are found in patients with bipolar disorder in remission and in patients with schizophrenia.     

The profile of executive function in OCD hoarders and hoarding disorder

Hoarding disorder is a new mental disorder in DSM-5. It is classified alongside OCD and other presumably related disorders in the Obsessive-Compulsive and Related Disorders chapter. We examined cognitive performance in two distinct groups comprising individuals with both OCD and severe hoarding, and individuals with hoarding disorder without comorbid OCD. Participants completed executive function tasks assessing inhibitory control, cognitive flexibility, spatial planning, probabilistic learning and reversal and decision making. Compared to a matched healthy control group, OCD hoarders showed significantly worse performance on measures of response inhibition, set shifting, spatial planning, probabilistic learning and reversal, with intact decision making. Despite having a strikingly different clinical presentation, individuals with only hoarding disorder did not differ significantly from OCD hoarders on any cognitive measure suggesting the two hoarding groups have a similar pattern of cognitive difficulties. Tests of cognitive flexibility were least similar across the groups, but differences were small and potentially reflected subtle variation in underlying brain pathology together with psychometric limitations. These results highlight both commonalities and potential differences between OCD and hoarding disorder, and together with other lines of evidence, support the inclusion of the new disorder within the new Obsessive-Compulsive and Related Disorders chapter in DSM-5.     

Impairment in cognitive and affective empathy in patients with brain lesions: anatomical and cognitive correlates

The present study was designed to examine the degree of impairment in cognitive and affective empathy among patients with focal brain lesions, and the contribution of specific cognitive abilities (such as cognitive flexibility and processing of emotional information), to empathy. The cognitive and affective empathic response of patients with localized prefrontal lesions (n=36) was compared to responses of patients with parietal lesions (n=15) and healthy control subjects (n=19). Results indicate that patients with prefrontal lesions (especially those with lesions involving the orbitoprefrontal and medial regions) were significantly impaired in both cognitive and affective empathy as compared to parietal patients and healthy controls. When the damage was restricted to the prefrontal cortex, either left- or right-hemisphere lesions resulted in impaired empathy. However, when the lesion involved the right hemisphere, patients with parietal lesions were also impaired. The pattern of relationships between cognitive performance and empathy suggested dissociation between the cognitive correlates of affective and cognitive empathy.     

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.     

Neuroanatomical correlates of executive functioning in depressed adults with type 2 diabetes

Depression is often comorbid with type 2 diabetes. Depression may increase vulnerability to and/or exacerbate existing cognitive deficits. Little is known about the brain pathophysiology underlying depression and cognitive abnormalities in diabetes. The aim of this study was to examine the relationship of orbitofrontal and anterior cingulate volumes with executive functioning and attention/processing speed in type 2 diabetic participants with and without major depression. A total of 21 diabetic participants with major depression, 23 diabetic participants with no depression, and 22 healthy controls were compared. Using brain magnetic resonance imaging, volumetric measures of the prefrontal cortex were examined in relation to executive functioning and attention/processing speed. Partial correlations suggested a significant positive relationship between right orbitofrontal regions and executive functioning in the group with diabetes and depression only, indicating that neurobiological changes in the orbitofrontal region may contribute to observed cognitive dysfunction.     

Analysis of the Difference between Psychiatric Symptoms and Cognitive Functions in Different Mental Disorders

Objective To analyze the psychiatric symptoms and cognitive functions in patients with depression,bipolar disorder I and II or schizophrenia. Methods Sixty severe depression patients,sixty bipolar disorder patients and sixty schizophrenia patients were selected from January 2015 to January 2016 in our hospital and they were divided into depression group,bipolar group and schizophrenia group. The bipolar group was classified into bipolar I subgroup and bipolar II subgroup. Sixty healthy persons in the same period were selected as the control group to compare the psychiatric symptoms,memory ability and cognitive functions among the groups. Results The score of attention/alertness and executive function of patients in bipolar I group was significantly higher than that in bipolar II group(P 0.05);the score of attention/alertness,executive function,and learning and memory and processing speed of patients in schizophrenia group was significantly lower than those in those in depression group,bipolar I group and bipolar II group(P 0.05). The score of executive function of patients in depression group was significantly lower than that in bipolar I group,and the score of processing speed was significantly higher than that in bipolar I group(P 0.05). Conclusion There was difference between mental symptoms and cognitive functions in patients with bipolar disorders I II,severe depression and schizophrenia,which is helpful to improve the rate of right diagnosis.     

Relative sparing of executive functions in the early phase of schizophrenia

Findings about the impairment of executive functions in schizophrenia are not conclusive. The authors hypothesized that the severity of the impairments in the abilities that comprise EF might be different. Forty patients were assessed with a comprehensive battery that included four measures of executive functions and were compared with 60 healthy subjects. Set shifting and response inhibition showed no significant between-group differences. Mental flexibility and concept formation were significantly worse in patients, but the effect sizes were small. Some executive functions might be relatively spared, at least in the early phase of schizophrenia. Studies on individual executive functions may yield more replicable findings.     

The sensitivity and psychometric properties of a brief computer-based cognitive screening battery in a depression clinic

At present, there is poor accuracy in assessing cognitive and vegetative symptoms in depression using clinician or self-rated measures, suggesting the need for development of standardized tasks to assess these functions. The current study assessed the psychometric properties and diagnostic specificity of a brief neuropsychological screening battery designed to assess core signs of depression; psychomotor retardation, attention and executive functioning difficulties, and impaired emotion perception within an outpatient psychiatry setting. Three hundred eighty-four patients with mood disorders and 77 healthy volunteers participated. A large percentage of patients met diagnostic criteria for Major Depressive Disorder alone (49%) or with another comorbid psychiatric disorder (24%). A brief, 25-min battery of computer-based tests was administered to control participants and patients measuring the constructs of inhibitory control, attention, visual perception, and both executive and visual processing speed. The patient groups performed significantly worse than the control group regardless of diagnosis on visual perception and attention accuracy and processing speed factors. Surprisingly, the anxiety disorder group performed better than several other psychiatric disorder groups in inhibitory control accuracy. Developing valid and reliable measures of cognitive signs in mood disorders creates excellent opportunities for tracking cognitive status prior to initiation of treatment, and allows for reliable retest following treatment.     

Theory of mind in schizophrenia: The role of clinical symptomatology and neurocognition in understanding other people's thoughts and intentions

A wealth of studies has demonstrated that patients with schizophrenia are impaired in “theory of mind” (ToM). Here, we used a novel five-factor model of the Positive and Negative Syndrome Scale (PANSS) to test the hypothesis that selectivity of ToM deficits in schizophrenia depends on the predominating symptoms. We predicted that ToM impairments would be non-selective in patients with pronounced negative (NF) or disorganized symptoms (DF), whereas selective ToM impairment would occur in patients with predominant positive symptoms (PF). We recruited 50 patients diagnosed with schizophrenia or schizoaffective disorder and examined premorbid intelligence, executive functioning, ToM and psychopathology in comparison to a group of 29 healthy controls. Compared with healthy controls, patients performed more poorly on tasks involving executive functioning and ToM abilities. Using a novel PANSS five-factor model, we found a significant association of ToM deficits with the “disorganization” factor. Moreover, several individual PANSS items that were included within the disorganization factor correlated with impaired ToM, albeit the majority of correlations disappeared when controlled for executive functioning, and, to a lesser degree, when controlled for IQ. In addition, in the patient group we found interactions of poor ToM with symptoms belonging to the “emotional distress” factor of the PANSS. Contrary to expectations, associations of impaired ToM with positive symptoms were absent, and poor with regards to negative symptoms. This study lends further support to the assumption of differential associations of ToM deficits with individual symptoms and symptom clusters in schizophrenia.     

Specific executive dysfunction in patients with first-episode medication-naïve schizophrenia

Many studies have shown that schizophrenia is associated with a wide range of cognitive impairments. Empirical findings suggest that patients with schizophrenia suffer from a "dysexecutive syndrome". However, the extent to which a general decline in neuropsychological function accounts for symptoms of executive dysfunction in schizophrenia is not clear. In this study, we examined further the nature and pattern of executive function in a sample of medication-na?ve patients experiencing a first-episode of schizophrenia with a set of tests capturing the specific components of executive function. We also compared the performance of this clinical group with healthy controls. A total of 78 medication-na?ve patients with first episode schizophrenia were recruited from the Early Assessment Service for Young People with Psychosis (EASY). Another 60 healthy controls were recruited for comparison. All subjects participated in a comprehensive set of executive function tests assessing initiation, sustained attention, online updating, switching, attention allocation, inhibition, and non-executive function. The executive function of patients with first-episode schizophrenia was found to be compromised relative to healthy controls. However, unlike patients with established schizophrenia, first episode patients exhibited only a limited deficit in sustained attention. Moreover, the majority of executive function deficits did not correlate with intellectual functioning and memory impairment in a sub-group of first episode patients without intellectual impairment. These findings suggest that first-episode patients exhibit a specific pattern of executive dysfunction compared to healthy controls and patients with an established illness. This differential breakdown of executive function components is unlikely to be an artefact of general intellectual decline or memory impairment in schizophrenia.     

Brain activation measured with fMRI during a mental arithmetic task in schizophrenia and major depression

OBJECTIVE: The authors used functional magnetic resonance imaging (fMRI) to investigate brain activation in patients with schizophrenia and major depression while they performed two tasks-a vigilance task and a mental arithmetic task-that differed in cognitive complexity. METHOD: In the vigilance task, the participants had to press a response button whenever a specific number was seen on a screen inside the MR scanner. In the mental arithmetic task, the participants had to add two consecutive numbers and press the response button whenever the sum was 10. fMRI was performed with a 1.5-T MR scanner. Twelve patients with recurrent nonpsychotic unipolar major depression, 12 patients with schizophrenia, and 12 healthy comparison subjects were included in the study. RESULTS: Performance data showed that the patients were impaired relative to the comparison subjects and showed no difference in performance between the patient groups. The patients with schizophrenia, but not those with major depression, had less activation in prefrontal brain regions, relative to the comparison participants. However, subtracting brain activation during the vigilance task from activation during the mental arithmetic task showed that the schizophrenia patients had activation in parietal areas. CONCLUSIONS: A double dissociation of parietal and frontal lobe activation was found for the schizophrenia patients and the depression patients. The greater parietal lobe activation in the patients with schizophrenia may reflect a compensatory strategy for the failure to recruit cognitive processes that involve frontal lobe areas when solving a mental arithmetic task.