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PubMed2006

Reasoning under uncertainty: heuristic judgments in patients with persecutory delusions or depression.

OBJECTIVE: The substantial literature examining social reasoning in people with delusions has, to date, neglected the commonest form of decision making in daily life. We address this imbalance by reporting here the findings of the first study to explore heuristic reasoning in people with persecutory delusions. METHOD: People with active or remitted paranoid delusions, depressed and healthy adults performed two novel heuristic reasoning tasks that varied in emotional valence. RESULTS: The findings indicated that people with persecutory delusions displayed biases during heuristic reasoning that were most obvious when reasoning about threatening and positive material. Clear similarities existed between the currently paranoid group and the depressed group in terms of their reasoning about the likelihood of events happening to them, with both groups tending to believe that pleasant things would not happen to them. However, only the currently paranoid group showed an increased tendency to view other people as threatening. CONCLUSION: This study has initiated the exploration of heuristic reasoning in paranoia and depression. The findings have therapeutic utility and future work could focus on the differentiation of paranoia and depression at a cognitive level.

Adult↗
PubMed1996

The Misdiagnosis of Hallucinations and Delusions in Persons with Mental Retardation: A Neurodevelopmental Perspective.

The identification of psychotic features in persons with mental retardation is challenging as the presence of hallucinations and delusions are disclosed through verbal self-report. In persons with mental retardation, self-report data is limited in utility because of the neuropsychological impairments that are uniformly reflected in limited communication and linguistic functions. Two major areas of misdiagnosis occur when interpreting reported hallucinations and delusions. First, the patient with mental retardation may experience a true hallucination or delusion, the content of which is very bizarre or disjointed, leading clinicians to identify schizophrenia or psychotic disorders when the condition is far less severe. Second, the patients's reported phenomena are not true hallucinations or delusions, but are instead self-talk, imaginary friends, or fantasy, similar to normal coping mechanisms of children. Mental health professionals must give priority to vegetative symptoms and mood states during the diagnostic assessment. It is also recommended that multiple sources of caregiver data be collected and that psychological projective testing be used as part of the evaluation process. Further, a false-positive strategy should be adopted when initiating treatment, favoring underdiagnosis of psychotic disorders.

Journal Article↗
PubMed2005

Schizophrenia, theory of mind, and persecutory delusions.

INTRODUCTION: There is already a substantial body of evidence supporting Frith's (1992) theory that theory of mind (ToM) is impaired in people with schizophrenia. However, a specific relationship between impaired ToM and paranoid delusions, while intuitively reasonable, has only been demonstrated in two studies to date. METHODS: A total of 25 participants with schizophrenia were classified as paranoid or nonparanoid and compared with 38 healthy controls on a variety of ToM tasks. These tasks included verbal and nonverbal, and first and second order ToM tasks. RESULTS: Participants with schizophrenia performed significantly more poorly than healthy controls on both the first and second order verbal ToM tasks but not on the nonverbal ToM tasks. However, the ToM deficit was only observed for those participants with schizophrenia who had persecutory delusions. There was also a strong relationship observed between the severity of persecutory delusions and length of illness. CONCLUSIONS: This study represents only the third demonstration of a specific link between paranoid delusions and ToM impairment. Reasons why previous findings on this issue have been so inconsistent are considered. Further research is needed to explore the relationships among paranoia, ToM, and length of illness.

Journal Article↗
PubMed2003

Visual scanpaths and facial affect recognition in delusion-prone individuals: Increased sensitivity to threat?

INTRODUCTION: Using visual scanpaths as a measure of directed attention, we investigated whether delusion-prone individuals would exhibit reduced visual appraisal, and impaired recognition accuracy, for threat-related facial expressions. METHODS: 47 psychiatrically healthy individuals completed the Peters et al. Delusions Inventory (PDI) as an index of delusion-proneness; experimental groups of high and low PDI scorers were formed on the basis of a median split. Visual scanpaths were recorded while participants viewed photographs of faces displaying anger, fear, happy, sad, and neutral expressions under a free-viewing condition. Affect recognition accuracy was assessed using a forced-choice response format. RESULTS: The high PDI group displayed generally "extended" scanpaths, characterised by increased distances between fixations, for angry, fearful, and happy faces, but exhibited a distinctive pattern of reduced foveal attention (fewer fixations) for facial expressions of anger and fear. Impaired affect recognition accuracy in the high PDI group was most pronounced for fearful faces. Reduced recognition accuracy for fearful faces was associated with longer distances between fixations in the entire group. CONCLUSIONS: Delusion-prone individuals displayed a bias of directing attention away from threat-related faces, and a trend toward reduced recognition accuracy for fearful faces, suggesting that these individuals may be particularly sensitive to facial threat.

Journal Article↗
PubMed2006

Delusion symptoms are associated with ApoE epsilon4 allelic variant at the early stage of Alzheimer's disease with late onset.

Alzheimer's disease (AD) is a neurodegenerative disorder with mixed cognitive and behavioural clinical manifestations. The possession of apolipoprotein-E (ApoE) epsilon4 allelic variant is one of the most important risk factors for developing late-onset AD (LOAD). In this study we analysed the relationship between the entire range of behavioural symptoms, cognitive deficit, and sociodemographic characteristics and ApoE epsilon4 allele possession with multivariate logistic regression models in LOAD patients. Patients included (n = 171) were consecutively admitted in a memory clinic for the first diagnostic visit. Levels of behaviour and cognition within the last month were assessed by the Neuropsychiatric Inventory and Mini Mental State Examination. Presence of clinically significant psychosis, delusions and hallucinations at the early stage of the illness, from the onset to the first visit, was measured with diagnostic criteria. ApoE epsilon4 allele possession was associated with increased levels of delusions within the last month from the first visit (OR 1.23; 95% CI 1.01-1.50; P < 0.05) and with the presence of categorical delusions at the early stage until the first visit (OR 3.11; 95% CI 1.21-8.01; P < 0.02). In this study, which considers the entire range of behavioural expressions in LOAD patients at the early stage of the illness, the relationship between behaviour and ApoE epsilon4 allele is confirmed for delusions only.

Age of Onset↗
PubMed1995

Use of the delusions-symptoms-states inventory to detect psychiatric symptoms in a sample of homeless men.

BACKGROUND: Previous research, often using the symptom-sign inventory, had demonstrated a high prevalence of psychiatric disorder among homeless people. The delusions-symptoms-states inventory detects the presence or absence of four classes of psychiatric illness--delusions of disintegration, integrated delusions, neurotic symptoms and dysthymic states. AIM: A study was undertaken to determine the utility of the delusions-symptoms-states inventory in a sample of homeless men, and the prevalence of psychiatric symptoms in this group. METHOD: The inventory was administered to 55 homeless men in a reception centre in Sheffield. RESULTS: Nearly half of the men obtained scores on the inventory suggesting that they had psychiatric symptoms. There was an overlap of syndromes, particularly among those with severe psychiatric illness. For example, seven men had all four classes of psychiatric illness. CONCLUSION: Use of the questionnaire proved satisfactory. The findings support the contention that reception centres and similar accommodation are repositories for homeless mentally ill people.

England↗
PubMed2003

[Development of delusion in view of Luhmann's systems theory].

The systems theory of Niklas Luhmann declares itself as a universal theory and therefore claims applicability to any social and psychic phenomenon.In spite of its high complexity, to many it seems too vague and nonspecific. The possible usefulness of this theory should be demonstrated on the example of the development of delusion, still a mysterious and unexplained phenomenon. Within the framework of Luhmann's systems theory, delusion can be considered a communication disorder and therefore a phenomenon within the social system. Both the autopoietic systems society and psyche are based on and processed by meaning but cannot communicate directly, and they are mutually nontransparent and unpredictable. Due to this fact, the interface between the two systems is a potential source of disturbances. Luhmann defines the distinction of information, message, and understanding as the crucial element to connect the social system with the psychic one. If the psychic system fails to recognize the message of an information correctly or is unable to negotiate between understanding and misunderstanding messages, it detaches itself from the social system to which it is normally closely connected. This detachment releases the possibility of unhindered autistic fulfillment of desires and uncontrolled fear. Due to the meaning-based autopoiesis of the psychic system,these released thoughts and emotions still appear in meaningfully condensed form as delusions.

Autistic Disorder↗
PubMed1994

The self, attributional processes and abnormal beliefs: towards a model of persecutory delusions.

In this paper we review a series of recent investigations into cognitive abnormalities associated with persecutory delusions. Studies indicate that persecutory delusions are associated with abnormal attention to threat-related stimuli, an explanatory bias towards attributing negative outcomes to external causes and biases in information processing relating to the self-concept. We propose an integrative model to account for these findings in which it is hypothesized that, in deluded patients, activation of self/ideal discrepancies by threat-related information triggers defensive explanatory biases, which have the function of reducing the self/ideal discrepancies but result in persecutory ideation. We conclude by discussing the implications of this model for the cognitive-behavioural treatment of paranoid delusions.

Attention↗
PubMed1993

Physostigmine ameliorates the delusions of Alzheimer's disease.

Alzheimer's disease (AD) patients frequently manifest delusions, and the cholinergic deficiency of AD may contribute to this aspect of the psychopathology of the disorder. In a double-blind, crossover study involving two patients, we compared the antidelusional efficacy of physostigmine, an acetylcholinesterase inhibitor, with haloperidol, a widely used neuroleptic agent. Physostigmine ameliorated the delusions and produced fewer side effects. These preliminary observations suggest that the cholinergic deficiency contributes to the occurrence of delusions in AD and cholinergic therapy may have a role in the treatment of the delusional symptoms.

Aged↗
PubMedDate not supplied

Cotard's delusion or syndrome?: a conceptual history.

This report offers an account of the historical construction of Cotard's syndrome showing that by délire des négations the French author meant a subtype of depressive illness. Subsequent debate led first to the belief that it was just a collection of symptoms associated with agitated depression (anxious melancholia) or general paralysis, and later to the view that it might after all constitute a separate entity. At the present moment, and impervious to the fact that the French term délire means far more than "delusion," some authors use Cotard's syndrome to refer to the belief of being dead and suggest that such a delusion might have a specific brain location. From the clinical and evolutionary perspective, it is unclear why a delusion should merit, simply because of its "nihilistic" content, a special brain location or presage chronicity. It is suggested here that before neurobiologic speculation starts, efforts should be made to map out the clinical features and correlations of the délire des négations.

Attitude to Death↗
PubMed1986

Defensive projection and paranoid delusions.

The present study considered the implication of a new explanation of defensive projection for the thematic qualities of schizophrenic delusions. Projection was proposed to be a form of self-deception practiced by people who make excessive use of social comparison in self-evaluation. Defensive projection occurs when an unacceptable quality is minimized by distorting this quality in other people used as standards of comparison. Reactive paranoid schizophrenics were expected to show projection as a distortion of social comparison and process paranoid schizophrenics were not. This was tested in terms of a number of thematic qualities that should appear in actual delusions of reactive paranoids but not in those of process paranoids (i.e. more specific social references, attribution of untrustworthiness by men, attribution of hostility by women, concern with female identity in women). The results confirmed these predictions and supported the social-comparison interpretation of projection as a defense in reactive schizophrenics that contributes to the development of delusions.

Adult↗
PubMed1994

Systematized delusions and neuropsychological function in paranoid and nonparanoid schizophrenia.

We extended research originating with the Tsuang-Winokur criteria for paranoid and nonparanoid schizophrenia. To partially resolve problems of subtype instability, 41 consecutive admissions meeting DSM-III-R criteria for schizophrenia were subdivided according to whether they ever experienced prominent systematized delusions. Neuropsychological profiles for paranoid patients and nonparanoids with a history of systematized delusions were extremely similar. When combined, this 'systematized' group had significantly better general verbal ability and verbal memory than patients who never manifested systematized delusions. There was also a significant neuropsychological function-by-group interaction. The neuropsychological data suggested that systematized patients had better premorbid cognitive functioning as well as a greater discrepancy between premorbid verbal ability and current attentional functioning. No between-group differences were found on a measure of prefrontal-executive function, nor were there any neuropsychological differences between traditionally defined (DSM-III-R) paranoid and nonparanoid subgroups. This study suggests a possible shift in the dividing line between paranoid and nonparanoid subtypes and illustrates the potential value of neuropsychological data for refining psychiatric nosologies.

Adult↗
PubMed2005

Need for closure and anxiety in delusions: a longitudinal investigation in early psychosis.

This study investigated the role of need for closure (NFC) and anxiety in delusions. The Need For Closure Scale (NFCS) and measures of trait and state anxiety were administered to an early psychosis group with current delusions, a clinical (generalised anxiety disorder--GAD) control group and a non-clinical control group. The battery of questionnaires was repeated at follow-up one year later. The NFCS did not meet criteria for a unidimensional scale and two sub-scales were removed from all further analyses. At baseline the deluded and GAD groups scored significantly higher on the reduced NFCS (NFCS-R) than the control group. Trait anxiety was related to NFCS-R in the GAD and non-clinical control groups, but not in the deluded group. At follow-up all groups scored significantly lower on the NFCS-R, perhaps suggesting a practice effect, although the two clinical groups continued to have higher scores than the non-clinical control group. The recovered and non-recovered deluded groups did not differ on the NFCS-R one year later, unlike in the GAD group where recovered participants had significantly lower scores than the non-recovered. Change scores on the NFCS-R and trait anxiety were correlated at trend level in the GAD and non-clinical control groups, but not in the deluded group. These findings suggest that whilst NFC and trait anxiety are related in non-psychotic groups, NFC may be implicated in the formation of delusions, independently of anxiety, in psychotic individuals.

Adolescent↗
PubMed2005

The neural basis of hallucinations and delusions.

Schizophrenia is a biologically based disorder characterised by false perceptions (hallucinations) and false beliefs (delusions). The underlying physiological cause of these mental abnormalities remains unknown. There is increasing evidence that one class of symptom, the 'made experiences' including delusions of alien control and thought insertion, is associated with abnormalities in the mechanism that predicts the outcome of intended actions (the forward model). For these patients active movements feel like passive movements. As a result these patients do not feel in control of their actions. However, comparison with various neurological disorders, such as those associated with parietal lobe lesions, suggest that this abnormal experience is not sufficient to explain the feeling that some other agent is controlling is one's actions. Preliminary evidence suggests that patients with schizophrenia have an exaggerated sense of agency. In combination with the feeling of not being in control, this exaggerated sense of agency could explain delusions of alien control in which the patient attributes his own actions to another agent. Little is yet know about the neural basis of the predictive mechanisms that create the feeling that we are in control of our movements. Such prediction requires integration of information about intended movements generated in frontal cortex with sensory processing in posterior regions of the brain. Measures of functional connectivity suggest that long-range interactions between frontal and posterior regions are abnormally reduced in patients with schizophrenia. Further research is needed to explore the precise involvement of long-range connections in the mechanisms of forward modelling.

Animals↗
PubMed2003

A comparison of metacognitions in patients with hallucinations, delusions, panic disorder, and non-patient controls.

This study tested the hypothesis that metacognitions are a general vulnerability factor for psychological disorder. It was predicted that patients with psychosis (hallucinations or delusions), and patients with panic disorder would score higher than non-patients on measures of metacognition. Moreover, it was hypothesised that patients showing most dysregulation of thinking (voice-hearers) would endorse significantly higher metacognition scores than individuals in the other groups. The Meta-Cognitions Questionnaire (MCQ: ) was administered to patients who met DSM-IV criteria for schizophrenia spectrum disorders with auditory hallucinations, patients who met DSM-IV criteria for schizophrenia spectrum disorders with persecutory delusions, patients who met DSM-IV criteria for panic disorder and non-patients. The results showed that psychotic patients who experience auditory hallucinations tended to exhibit higher levels of dysfunctional metacognitive beliefs than other patient groups, scoring significantly higher than at least two of the three control groups on positive beliefs about worry, negative beliefs about uncontrollability and danger, cognitive confidence and negative beliefs including superstition, punishment and responsibility. It was also found that the metacognitive beliefs of patients with persecutory delusions and panic patients were often similar to each other, and elevated in comparison to non-patients, suggesting that such beliefs are generic vulnerability factors. The theoretical and clinical implications of these findings are discussed.

Adult↗
PubMed1989

Delusions of fatal contagion among refugee patients.

Delusions of fatal contagion were encountered in about 10% of refugee psychiatric patients from Southeast Asia belonging to one ethnic group, the Hmong. Psychotic depression was the most common diagnosis among the Hmong patients with delusions of contagion, whereas paranoid and schizophrenic diagnoses predominate in patients with similar delusions from other refugee groups. Some cases also occurred as a shared delusional disorder. Associated findings included isolation from the community, intrafamilial conflict, failure to acculturate, and sexual frustration or conflict. Most patients responded to tricyclic medication, later supplemented in about half of the cases with a neuroleptic. This syndrome, which does not appear to have been described previously, should be considered in cases of somatizing refugees who present repeatedly to medical facilities.

Adolescent↗
PubMed2004

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.

Adult↗
PubMed1999

A rating scale for psychotic symptoms (RSPS): part II: subscale 2: distraction symptoms (catatonia and passivity experiences subscale 3: delusions and semi-structured interview (SSCI-RSPS).

In the second paper on the Rating Scale for Psychotic Symptoms (RSPS), distraction symptoms (Subscale 2) and delusions (Subscale 3) are described. Subscale 2 includes distraction symptoms, which arise from one of two mechanisms: the symptom may arise either by loss of attentional focus (LAF) due to a competing channel of information, or by the intrusion of the competing channel into the focus of attention [attentional intrusions (AI)]. The symptom classes resulting from loss of attentional focus (LAF) include motor catatonia, negativism, and thought blocking; the attentional intrusions (AI) symptoms rated include three types of passivity experiences (Schneiderian symptoms): (1) thought insertion, (2) movements or action controlled, and (3) speech controlled by an external force. Subscale 3, consisting of delusions, is organized on the basis of content identification. Nineteen types of delusions are rated. Each item of delusional content is rated along three axes (active elaboration, persistence and active extinction) and complexity, and optionally if primary or mixed (i.e. primary with secondary elaborations). The last section of the paper includes the semi-structured interview (SCI-RSPS) for each of the items, as well as guidelines for practical application of the interview.

Association↗