Neuropsychologische Aspekte wahnhafter Störungen

BACKGROUND: "Pure" delusional disorders are clinically rare, and the neuropsychology of such disorders is poorly understood. Whereas "deficit" models suggest a cognitive impairment accounting for the incorrigible fixation of false beliefs, cognitive models propose the existence of a characteristic attributional style in patients to stabilise a fragile self. PATIENTS AND METHODS: The cognitive flexibility and attributional style of 21 patients diagnosed with delusional disorder according to ICD-10 were compared with a group of healthy controls paralleled for age, sex, education, and intelligence. RESULTS: Patients with delusional disorders made more errors and more perseverative errors in the Wisconsin Card Sorting Test compared with controls. However, these differences were only significant in patients with a comorbid depression. In contrast to earlier studies, patients with delusional disorders did not attribute negative events to external or personal causes more often than healthy controls, but partly tended to show a depressive attributional style. CONCLUSION: Our results do not support either a cognitive deficit in patients with delusional disorders or a characteristic attributional style. In terms of treatment recommendations, a thorough diagnosis of comorbid depressive disorders in patients with delusional disorders is warranted.     

Mentalizing in first-episode psychosis

Mentalizing deficits have often been observed in people with schizophrenia and a few recent studies suggest that such deficits are also present in patients with first episode psychosis (FEP). It is not clear, however, whether these mentalizing deficits in FEP can be accounted for by underlying processes such as social cue recognition, social knowledge and general reasoning. In this study, we assessed mentalizing abilities in 31 people with FEP and 31 matched controls using a novel, comprehensive mentalizing task validated through the present study. We also assessed social cue recognition, social knowledge and non-social (or general) reasoning performance in the same participants in order to determine if the mentalizing deficits in FEP can be at least partly explained by performance in these three underlying processes. Overall, the mentalizing task revealed the greatest impairment in FEP, an impairment that remained significant even after controlling for social cue recognition, social knowledge and non-social reasoning performance. Interestingly, non-social reasoning and social knowledge were both shown to contribute to mentalizing performance. In addition, social cognition measures were linked to social functioning in the FEP group, with the strongest correlation observed with mentalizing performance. Taken together, these results show that mentalizing is an aspect of social cognition that is particularly affected in FEP and might contribute to functional impairments in these patients. These deficits could be a prime target for cognitive remediation in FEP, and our results suggest that this could be done either directly or through improvement of related social and non-social cognitive skills such as social knowledge and general reasoning.     

Attributional style in schizophrenia: an investigation in outpatients with and without persecutory delusions

The attributional style of outpatients with schizophrenia with and without persecutory delusions was investigated. Thirty individuals with schizophrenia were divided into persecutory-deluded and non-persecutory-deluded groups based on a score of 5 or higher on the suspiciousness item from the Expanded Brief Psychiatric Rating Scale (BPRS-E). The two resulting groups, and a nonclinical control group, were administered a battery of attributional measures, and their attributional responses were coded by both the subjects themselves and a pair of independent raters. The results showed evidence of a self-serving bias for subjects with persecutory delusions; however, this bias was not unique to those with persecutory delusions, and it disappeared when independent raters evaluated subjects' causal statements on a reliable measure of attributional style. Subjects with persecutory delusions tended to show a stronger bias toward blaming others rather than situations for negative outcomes, and there was a linear association between persecutory ideation and a self-serving attributional style. Finally, there were significant discrepancies between the attributional ratings of the persecutory-deluded subjects and those of independent judges. Implications for future research are discussed.     

Mentalizing in preclinical Huntington’s disease: an fMRI study using cartoon picture stories

Huntington’s disease (HD) is an autosomal dominant degenerative brain disorder that is characterized by motor, cognitive and affective symptoms. Previous research has shown that patients with HD, similar to patients with schizophrenia, are impaired in their ability to appreciate the mental states of others. Functional brain imaging studies have shown that patients with schizophrenia underactivate the neural network involved in mentalizing, and that deviant patterns of brain activation are also present in individuals at high risk of developing a psychotic disorder. Accordingly, the present study sought to examine the brain activation in premanifest mutation carriers for HD. Thirty premanifest mutation carriers (13 males) defined by a positive gene test and absence of unequivocal HD symptoms (“pre-HD”) performed a cartoon mentalizing task during functional brain imaging. For comparison, a group of 26 healthy controls took part in the study. BOLD responses revealed that pre-HD subjects activated the mentalizing network comprising prefrontal, temporoparietal and parietal brain regions during task performance. A comparison between pre-HD patients and healthy controls revealed no significant activation differences. Premanifest mutation carriers of HD activated the neural network involved in mentalizing similar to healthy control subjects. This suggests that impaired mentalizing emerges with the clinical manifestation of the disease, but is not necessarily part of the pre-manifest stage.     

Paranoia, persecutory delusions and attributional biases

An influential model of persecutory delusions put forward by Bentall and colleagues hypothesizes that persecutory-deluded patients avoid the activation of negative self-beliefs by making externalising, personalising attributions for negative events. The first study reported here used a new instrument for the measurement of persecutory ideation, the Paranoid, Persecutory and Delusion-Proneness Questionnaire, to investigate whether attributional biases are associated with subclinical persecutory ideation. The second study extended this investigation by re-examining associations between attributional biases and persecutory delusions. Both studies used the Internal, Personal and Situational Attributions Questionnaire to measure attributional style. No evidence was found for a connection between attributional biases and subclinical persecutory ideation. Furthermore, there was no support for an association between persecutory delusions and an externalising bias, and only marginal support for the hypothesized relationship between persecutory delusions and a personalising bias. These results suggest that the putative link between persecutory ideation and attributional biases only manifests (if at all) when persecutory ideation is of delusional intensity, and that it is confined to a personalising bias.     

The psychological effect of an urban environment on individuals with persecutory delusions: the Camberwell walk study

BACKGROUND: Epidemiological studies have found that individuals who live in urban areas are at increased risk of developing psychosis. However it is unknown whether exposure to urban environments exacerbates psychotic symptoms in people who have a diagnosed psychotic disorder. The aim of the study was to examine the psychological and clinical effects of exposure to one specific deprived urban environment on individuals with persecutory delusions. It was predicted that the urban environment would affect emotional and reasoning processes highlighted in a cognitive model of persecutory delusions and would increase paranoia. METHOD: Thirty patients with persecutory delusions were randomised to exposure to a deprived urban environment or to a brief mindfulness relaxation task. After exposure, assessments of symptoms, reasoning, and affective processes were taken. Thirty matched non-clinical participants also completed the study measures to enable interpretation of the test scores. RESULTS: In individuals with persecutory delusions, exposure to the urban environment, rather than participation in a mindfulness task, increased levels of anxiety, negative beliefs about others and jumping to conclusions. It also increased paranoia. The individuals with persecutory delusions scored significantly differently from the non-clinical group on all measures. CONCLUSIONS: For individuals with psychosis, spending time in an urban environment makes them think more negatively about other people and increases anxiety and the jumping to conclusions reasoning bias. Their paranoia is also increased. A number of processes hypothesised in cognitive models to lead to paranoid thoughts are exacerbated by a deprived urban environment. Further research is needed to clarify which aspects of urban environments cause the negative effects. Methodological challenges in the research area are raised.     

Persecutory beliefs, attributions and theory of mind: comparison of patients with paranoid delusions, Asperger's syndrome and healthy controls

Schizophrenia patients with persecutory delusions and patients with Asperger's syndrome were compared using two measures of theory of mind (ToM; the ability to infer mental states in other people), the Hints task, and the Reading the Mind in the Eyes task, and a new measure of attributional style (style of inferring the causes of important events), the Attributional Style Structured Interview (ASSI). Paranoid beliefs were measured using Fenigstien and Vanable's Paranoia Scale (PS). The deluded group had the highest scores on the Paranoia Scale but the scores of the Asperger's group's were higher than those of the controls. Paranoid patients made more external-personal attributions for negative events than the Asperger's and control groups. Both the paranoid and Asperger's groups performed poorly on the ToM tasks compared to the controls. The findings support the hypothesis that both ToM and attributional abnormalities contribute to paranoid delusions. The lack of attributional abnormalities in the Asperger's group suggests that their low-level paranoid symptoms arise as a consequence of different mechanisms than those involved in psychotic delusions.     

伴有被害妄想的精神分裂症患者症状归因风格研究

目的:探讨伴有被害妄想的精神分裂症患者症状归因风格及其相关影响因素。方法:采用精神分裂症症状归因问卷(SAQS)和简明精神病评定量表评估136例伴有被害妄想的精神分裂症患者(病例组),并与132名正常人(正常对照组)进行分析比较。结果:两组SAQS问卷中内在-外在、局部-整体和可控-不可控归因维度的组别效应显著(F=49.14,F=49.01,F=36.88;P均=0.00)。多元回归分析显示,患者内在-外在维度得分受首发年龄、病程、敌对性因子和宗教因素的影响(β=-0.205、-0.189、-0.556、-0.170;P0.001或P0.05);暂时-持久维度得分受住院次数、焦虑忧郁因子分和迟滞因子分的影响明显(β=0.313、0.342、-0.266;P0.05);局部-整体维度得分受敌对性因子分影响较大(β=0.227,P0.05)。结论:与正常人相比,伴有被害妄想的精神分裂症患者症状归因特点趋于外在的、整体的和不可控的归因风格,且可能会随某些因素的变化而发生改变。     

Healthy people with delusional ideation change their mind with conviction

Emotional distress and reasoning biases are two factors known to contribute to delusions. As a step towards elucidating mechanisms underlying delusions, the main aim of this study was to evaluate a possible “jumping to new conclusions” reasoning bias in healthy people with delusional ideation and its association with emotions. We surveyed 80 healthy participants, measuring levels of depression, anxiety, cognitive error and delusional ideation. Participants completed two versions of the beads task to evaluate their reasoning style. Results showed that people with delusional ideation reached a conclusion after less information, as expected. Interestingly, they also tended to change their conclusions more often than people without delusional ideation and did so with greater conviction. Depression and cognitive errors were strong predictors of delusional ideation but not of reasoning style. We conclude that delusional ideation in non-psychotic individuals is independently predicted by depressive symptoms and by a high conviction in new conclusions.     

Persecutory delusions and the self-serving bias. Evidence from a contingency judgment task.

The self-serving attributional bias was studied in matched groups of patients with persecutory delusions, patients with major affective disorder, and normal controls, (N = 14 in each group). On a preprogrammed computer task, subjects mainly won points in one condition and mainly lost points in the other. Subjects were asked to estimate the degree of control they thought they had over winning or losing in the two conditions. In comparison with the normal subjects and the psychiatric controls, the deluded subjects showed a greater self-serving bias, as evidenced by their perceived greater control over outcomes in the win condition. These findings are interpreted as consistent with the hypothesis that persecutory delusions function as a defense against low self-esteem.     

Attributional style in the eating disorders

Previous research has shown that patients with eating disorders have a characteristic cognitive bias, making internal attributions when evaluating negative events. However, there is less clarity about their attributions for positive events. There are suggestions that this cognitive style might be influenced by depressed mood. This study examines attributional style in the eating disorders for positive and negative events, independent of covariant effects of depression. Twenty-five eating-disordered women and 26 nonclinical women each completed measures of attributional style, depressed mood, and eating pathology. They also completed a measure of verbal intelligence (to ensure comparability of groups). Women with an eating disorder had a greater tendency to attribute negative situations to the self when compared with nonclinical women, even when differences in depressed mood were controlled for. There were no comparable differences in positive attributional biases. Women with an eating disorder adopt a self-blaming style when evaluating negative events, and such self-blame is likely to contribute to the maintenance of an eating disorder. This suggests that therapy for the eating disorders should include an element that focuses on highlighting and re-evaluating such interpretations.     

Cognitive performance in schizophrenia patients assessed before and following the first psychotic episode

BACKGROUND: The purpose of this historical prospective study was to follow the cognitive impairment in schizophrenia from the premorbid period until shortly after the onset of the first psychotic episode within the same subjects. METHODS: Forty-four first episode schizophrenia patients were enrolled in the study. Their cognitive performance was assessed as part of the Israeli Draft Board aptitude assessments at ages 16-17, when all were found to be in good mental health (first assessment) and again, following the manifestation of the first psychotic episode (second assessment). Forty-four healthy comparisons were also enrolled and tested twice, at the same ages as the patients. Both times, the assessments included four subtests assessing abstract reasoning (Raven Progressive Matrices-R), mental speed and concentration (Otis-R), verbal reasoning (Similarities-R), and mathematical abilities (Arithmetic-R). RESULTS: A within group analysis did not reveal statistically significant changes between the first and the second assessment among the schizophrenia patients on any measure. However, a between group comparison of changes showed that relative to the healthy comparisons, schizophrenia patients deteriorated on the RPM-R (p=0.021) and Otis-R (p<0.001), but not on the Similarities-R and Arithmetic-R. Schizophrenia patients performed worse than comparisons in all four subtests on the first and second assessments (all p<0.01). CONCLUSIONS: The results indicate that most of the cognitive impairment exhibited by first-episode schizophrenia patients precedes the first psychotic episode. A decline between ages 16 and 17 and the onset of psychosis is evident in some but not all cognitive functions.     

Reasoning under uncertainty in deluded schizophrenic patients: a longitudinal study.

Several current hypotheses consider the process of attribution of importance to stimuli and the integration of actually perceived reality with experience as a cognitive base for the genesis of delusions. We tested these models by a comparison of deluded schizophrenics, healthy controls, and anxious patients on reasoning under uncertainty. Reasoning under uncertainty was examined in currently deluded schizophrenics (n = 29), in 16 of them also in remission, in normal control groups (n = 35), and in anxious patients (n = 31) using a probabilistic inference task. Acutely psychotic schizophrenics were less ready than normal subjects, anxious patients, and schizophrenics, in remission to modify their judgement in probabilistic situation confronted with potentially disconfirmatory data. They were also less prone than anxious patients and schizophrenics in remission to correct their estimate confronted with confirmatory data. The data support the hypothesis of a weaker influence of incoming stimuli on reasoning under uncertainty as a cognitive base of the maintenance of delusions.     

Cognitive factors related to suicidal ideation and resolution in psychiatrically hospitalized children and adolescents

OBJECTIVE: This study was conducted to determine whether there are changes in the cognitive factors of attributional style, hopelessness, and self-esteem when suicidal ideation fades in psychiatrically hospitalized children and adolescents. METHOD: The cognitive factors of attributional style, hopelessness, and self-esteem were assessed in subjects aged 7-17 years (50 with and 50 without suicidal ideation) at admission and discharge from a psychiatric hospital. RESULTS: For subjects with suicidal ideation, attributional style became significantly more positive and hopelessness was decreased from admission to discharge, by which time suicidal ideation had faded. There was no association between self-esteem and suicidal ideation after control for depression. These changes in cognitive factors were not seen in the group without suicidal ideation. There were no significant differences between children and adolescents in the pattern of results. CONCLUSIONS: Change in attributional style was shown to be a factor significantly related to the resolution of suicidal ideation in children and adolescents. This cognitive style could be specifically addressed in psychotherapy with depressed children and adolescents as a means of reducing suicidal ideation. These results may have an implication for reducing the length of psychiatric inpatient stays.     

Deterministic learning and attempted suicide among older depressed individuals: cognitive assessment using the Wisconsin Card Sorting Task

BackgroundLate-life suicide is an under-investigated public health problem. Among the putative vulnerabilities for this complex multifactorial behaviour are deficits in cognitive control, an ability to integrate and prioritize multiple cognitive processes in order to flexibly adapt behaviour and meet situational demands. We investigated cognitive control during rule learning in a complex and changing environment in older individuals with suicide attempts of varying lethality.MethodNinety-three participants over the age of 60 (30 healthy controls, 29 depressed never suicidal, 20 low-lethality suicide attempters, 14 high-lethality suicide attempters) underwent structured clinical and cognitive assessments. Participants then completed the Wisconsin Card Sorting Test (WCST), a well-studied task of cognitive control during rule learning.ResultsHigh-lethality attempters demonstrated a pattern of deficits involving poor conceptual reasoning, perseverative errors and total errors. Compared to low-lethality attempters and healthy controls, high-lethality attempters demonstrated poor conceptual reasoning, as well as increased rates of perseverative errors and total errors. Compared to non-suicidal depressed participants, high-lethality attempters also made more conceptual errors.ConclusionHigh-lethality suicide attempts among older people are associated with impaired cognitive control during rule learning as detected by the WCST. Our data suggest that impairment in cognitive control during rule learning may represent a vulnerability distinct from the impulsive diathesis, typically manifesting in young, low-lethality attempters. This vulnerability may contribute to the high incidence of serious or, often, fatal suicidal acts in old age.     

Reasoning anomalies associated with delusions in schizophrenia

Deluded people differ from nondeluded controls on attributional style questionnaires and probabilistic-reasoning and theory-of-mind (ToM) tasks. No study to date has examined the relations between these 3 reasoning anomalies in the same individuals so as to evaluate their functional independence and potentially inform theories of delusion formation. We did so in 35 schizophrenic patients with a history of delusions, 30 of whom were currently deluded, and 34 healthy controls. Compared with healthy controls, patients showed (a) a jumping-to-conclusions bias and a bias to overadjust when confronted with a change of evidence on probabilistic-reasoning tasks, (b) an excessive externalizing attributional bias, and (c) performance deficits on 3 ToM tasks. Probabilistic-reasoning and ToM measures correlated, while attributional-bias scores were independent of other task measures. A general proneness to delusional ideation correlated with probabilistic-reasoning and ToM measures, while externalizing bias was unrelated to the study measures of delusional ideation. Personalizing bias associated specifically with paranoia across the clinical and nonclinical participants. Findings are consistent with a common underlying mechanism in schizophrenia which contributes to the anomalies on probabilistic-reasoning and ToM tasks associated with delusions. We speculate that this mechanism is impairment of the normal capacity to inhibit "perceived reality" (the evidence of our senses), a capacity that evolved as part of the "social brain" to facilitate intersubjective communication within a shared reality.     

Relation of prefrontal cortex dysfunction to working memory and symptoms in schizophrenia.

OBJECTIVE: The dorsolateral prefrontal cortex has been implicated in both working memory and the pathophysiology of schizophrenia. A relationship among dorsolateral prefrontal cortex activity, working memory dysfunction, and symptoms in schizophrenia has not been firmly established, partly because of generalized cognitive impairments in patients and task complexity. Using tasks that parametrically manipulated working memory load, the authors tested three hypotheses: 1) patients with schizophrenia differ in prefrontal activity only when behavioral performance differentiates them from healthy comparison subjects, 2) dorsolateral prefrontal cortex dysfunction is associated with poorer task performance, and 3) dorsolateral prefrontal cortex dysfunction is associated with cognitive disorganization but not negative or positive symptoms. METHOD: Seventeen conventionally medicated patients with schizophrenia and 16 healthy comparison subjects underwent functional magnetic resonance imaging while performing multiple levels of the "n-back" sequential-letter working memory task. RESULTS: Patients with schizophrenia showed a deficit in physiological activation of the right dorsolateral prefrontal cortex (Brodmann's area 46/9) in the context of normal task-dependent activity in other regions, but only under the condition that distinguished them from comparison subjects on task performance. Patients with greater dorsolateral prefrontal cortex dysfunction performed more poorly. Dorsolateral prefrontal cortex dysfunction was selectively associated with disorganization symptoms. CONCLUSIONS: These results are consistent with the hypotheses that working memory dysfunction in patients with schizophrenia is caused by a disturbance of the dorsolateral prefrontal cortex and that this disturbance is selectively associated with cognitive disorganization. Further, the pattern of behavioral performance suggests that dorsolateral prefrontal cortex dysfunction does not reflect a deficit in the maintenance of stimulus representations per se but points to deficits in more associative components of working memory.     

Social cognition deficits and the 'ultra high risk' for psychosis population: a review of literature

Aim: A number of risk factors for developing a psychotic disorder have been investigated in the ‘ultra high risk’ (UHR) population, including neurocognitive abilities, social functioning and, more recently, social cognition. We aimed to review the literature on social cognition in the UHR population. Methods: Literature was restricted to English articles and identified using Pubmed, Medline, PsychINFO and CINAHLplus, as well as the reference lists of published studies and reviews. Search terms included social cognition, theory of mind, emotion recognition, attributional style, social knowledge, social perception, ‘at risk mental state’, psychosis prodrome ‘clinical high risk’ and ‘ultra high risk’. Inclusion criteria were an outcome measure of a social cognition task and an UHR population defined by a structured validated instrument. Results: Seven original research articles met the inclusion criteria, one of which was a conference abstract. One of the two studies that assessed theory of mind, two of the four studies that assessed emotion recognition and both the two studies that assessed social perception/knowledge found significant deficits in UHR patients. The single study that assessed attributional bias also reported differences in UHR patients compared with healthy controls. Conclusions: There is limited published literature on social cognitive performance in the UHR population. Despite this, deficits in certain social cognitive abilities do appear to be present, but further research with more reliable cross‐cultural measures is needed. The characterization of social cognitive deficits in the UHR populations may aid in the identification of potential markers for development of a subsequent psychotic disorder, as well as targets for early intervention.     

Cognitive neuropsychiatric models of persecutory delusions

OBJECTIVE: The major cognitive theories of persecutory delusion formation and maintenance are critically examined in this article. METHOD: The authors present a comprehensive review of the literature, citing results of relevant functional neuroimaging and neural network studies. RESULTS: People with persecutory delusions selectively attend to threatening information, jump to conclusions on the basis of insufficient information, attribute negative events to external personal causes, and have difficulty in envisaging others' intentions, motivations, or states of mind. Presence of the "reality distortion" cluster of psychotic symptoms correlates with cerebral blood flow in the left lateral prefrontal cortex, ventral striatum, superior temporal gyrus, and parahippocampal region. Social cognitive processing (selective attention to threat, attribution of causation or mental states) in normal subjects involves similar areas. Neural network models of persecutory delusions highlight the importance of disordered neuromodulation in their formation and of disordered neuroplasticity in their maintenance. CONCLUSIONS: Further studies examining the interaction of these cognitive processes, cross-sectionally and longitudinally, at cognitive psychological, neural network, and functional neuroanatomical levels are warranted to establish a comprehensive cognitive neuropsychiatric model of the persecutory delusion.     

Mood-congruent bias in affective go/no-go performance of unmedicated patients with major depressive disorder

OBJECTIVE: Neuropsychological studies of major depressive disorder have described attentional biases for affectively laden stimuli, but these reports were based on measures obtained from medicated subjects. This study investigated performance of unmedicated depressed patients on the Affective Go/No-Go Task. METHOD: Twenty depressed patients and 20 healthy comparison subjects, matched for age, gender, and IQ, performed the Affective Go/No-Go Task as well as tests of attention and memory for nonaffective stimuli. RESULTS: Depressed patients did not differ from healthy subjects on memory task performance, but they made more omission errors on the attention task. On the Affective Go/No-Go Task, depressed patients made more omission errors during happy than sad word blocks and required more time to respond to happy than to sad words. In contrast, healthy subjects required more time to respond to sad than to happy words. CONCLUSIONS: Unmedicated depressed patients do not show a pattern of generalized cognitive impairment but, rather, specifically display an attentional deficit and a mood-congruent bias toward salient stimuli.