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PubMed2006

Explaining delusions: a cognitive perspective.

There is now considerable evidence for reasoning, attention, metacognition and attribution biases in delusional patients. Recently, these findings have been incorporated into a number of cognitive models that aim to explain delusion formation, maintenance and content. Although delusions are commonly conceptualized as beliefs, not all models make reference to models of normal belief formation. This review considers those models that explain delusions as a breakdown of normal belief formation (belief-positive models), approaches that explain the pathology only (belief-negative models) and approaches that view delusions as one end of a distribution of anomalous mental phenomena (the continuum view). A cognitive theory that includes the 'pragmatic pathology' of delusions will be able to address both the phenomenology and the treatment of delusion-related distress.

Attention↗
PubMedDate not supplied

Bizarre delusions and first-rank symptoms in a first-admission sample: a preliminary analysis of prevalence and correlates.

This report examines the prevalence and correlates of bizarre delusions and Schneider's first-rank symptoms (FRS) in a first-admission sample with psychosis. A total of 196 patients were assessed with the Structured Clinical interview for DSM-III-R (SCID) and given a consensus diagnosis. Project psychiatrists blind to the consensus diagnoses coded each delusion and hallucination in the sample for both FRS and DSM-III-R bizarreness. Interrater reliability of bizarreness was lower than that of FRS (kappa = .681 v 861). The majority of symptoms (72%) were neither bizarre nor FRS, and of the remainder, bizarre delusions that were not also FRS were extremely uncommon. The prevalence of FRS was 70% in schizophrenia, 29% in psychotic bipolar disorder, and 18% in psychotic depression. For seven schizophrenic patients (7.45%), diagnosis of that disorder depended on the presence of a DSM-III-R bizarre delusion to meet criteria. There was a trend for FRS to be associated with poorer prognostic features in the schizophrenic sample. We concluded that although the constructs of bizarre delusions and FRS overlap, FRS were a more important feature in schizophrenia than bizarreness. The rarity of bizarre delusions that were not FRS, combined with the lower reliability of their assessment as compared with that of FRS, raises questions about the continued emphasis on this phenomenon in the definition of schizophrenia.

Adolescent↗
PubMedDate not supplied

Late-onset psychosis with somatic delusions.

The authors studied 10 patients who had late-onset psychosis with somatic delusions and 2 comparison groups similar in age and education: 9 late-onset psychosis patients without somatic delusions and 10 normal control subjects. Demographic, clinical, and neuropsychological data were obtained. Brain magnetic resonance imaging was also done and compared. The patients with somatic delusions were somewhat more likely to be women, have been ill longer, and meet DSM-III-R criteria for delusional disorder, compared with late-onset psychotic patients without somatic delusions. Patients with somatic delusions also had lower scores on a full-scale IQ test, compared with the normal comparison subjects. The patients with somatic delusions rarely benefitted from and poorly complied with treatment with psychotropics. The study's limitations, such as small sample size and heterogeneity of diagnosis, as well as the possible clinical implications of these findings are also discussed.

Age of Onset↗
PubMed1997

Violence in schizophrenia: role of hallucinations and delusions.

The study examines the relationship between hallucinations/delusions and violent behaviour in a sample of long-stay inpatients with chronic schizophrenia. Thirty-one subjects defined as violent and meeting DSM-111-R criteria for schizophrenia were compared with 31 matched non-violent schizophrenia patients with respect to detailed phenomenologies of auditory hallucinations using the Mental Health Research Institute Unusual Perceptions Schedule (Carter and Copolov, 1993; Carter et al., 1995) and delusions using the Maudsley Assessment of Delusions Schedule (Taylor et al., 1994). Patients in the violent groups were significantly more likely to experience negative emotions, tone and content related to their voices than those in the non-violent group, whilst patients in the non-violent group were more likely to experience positive emotions, tone and content related to their voices. Patients in the non-violent group were significantly more likely to report success in coping with their voices. There was no association between command hallucinations and violent behaviour. Patients in the violent group were more likely to hold persecutory delusional beliefs than those in the non-violent group, while patients in the non-violent group were likely to hold grandiose delusions than those in the violent group. Patients in the violent group were also more likely to report that the delusion made them feel angry, while those in the non-violent group were more likely to report that the delusion made them feel elated. The results suggest specific aspects of the phenomenologies of hallucinations and delusions that should be clinically assessed to determine the likelihood of violence as a result of such psychotic symptoms.

Adult↗
PubMedDate not supplied

Delusion formation and insight in the context of affective disturbance.

OBJECTIVE: Delusions and lack of insight have traditionally been viewed as the defining characteristics of insanity and in modern psychiatry continue to be central to the diagnosis of psychosis. Little is known about the mechanisms of delusion formation and much of the research into delusions and lack of insight has been focussed on schizophrenia, in spite of the fact that these symptoms are also prominent in other disorders e.g., affective psychosis. The objective of this paper is to review the literature on existing theories of delusions and insight with reference to the effects of affective disturbance on memory processes. METHOD: Narrative review supplemented by literature searches using Medline, PsycINFO and EMBASE databases for the period 1980 to present using terms "delusion", and "insight" and "affect". RESULTS: The role of affect on memory in normal psychology and delusions in psychopathology is being increasingly recognised. We sketch out a theory which gives weight to locating the formation and maintenance of mood congruent and mood incongruent delusional beliefs (and insight into such beliefs) within a model of normal memory processes. CONCLUSION: We conclude that delusional beliefs may represent false or biased memories of internal or external events modified and strengthened of by affective states. We propose that insight rests on an ability to identify these memories as internally generated or biased. In view of the growing body of knowledge accumulating from the study of memory, emotion and their neuropsychological correlates we would suggest using this as an evidence base for the further neuropsychiatric investigation of delusional beliefs.

Delusions↗
PubMed2002

Incomprehensibility: the role of the concept in DSM-IV definition of schizophrenic delusions.

In this paper the role of incomprehensibility in the conceptualization of the DSM-IV definition of delusion is discussed. According to the analysis, the conceptual dependence of DSM-IV definition of delusion on "incomprehensibility" is manifested in several ways and infested with ambiguity. Definition of "bizarre" delusions is contradictory and gives room for two incompatible readings. Also the definition of delusion manifests internal inconsistencies and its tendency to account for delusions in terms of misinterpretation is bound to miss the content of the traditional comprehension of delusionality. It is suggested that the ambiguities in defining delusions has to do with the question whether psychiatric practice is better accounted for in terms of the grammar of "incorrectness" or of "incomprehensibility".

Comprehension↗
PubMed2001

Delusions and delusional reasoning.

In 2 studies, delusional participants assigned higher probabilities to narratives of actual delusions than participants with no history of delusions; previously delusional participants did not differ significantly from delusional participants or participants with no history of delusions. In Study 2, the authors found that this reasoning bias was specific to delusions and did not generalize to "neutral" text. Familiarity with the content of the delusion narratives played a mediating role in the estimation of their probability, but delusional status also had a significant, independent effect. These findings are consistent with the Bayesian model of delusion formation proposed by D. R. Hemsley and P. A. Garety (1986), and with R. P. Bentall, P. Kinderman, and S. Kaney's (1994) concept of "emotional saliency." A productive area of future research might be to further determine the elements of "emotional saliency" and their impact on the individual steps of the Bayesian model.

Adult↗
PubMed2004

Why do people with delusions fail to choose more realistic explanations for their experiences? An empirical investigation.

Delusions can be viewed as explanations of experiences,. By definition, the experiences are insufficient to merit the delusional explanations. So why have delusions been accepted rather than more realistic explanations? The authors report a study of alternative explanations in 100 individuals with delusions. Patients were assessed on the following criteria: symptom measures, the evidence for the delusions, the availability of alternative explanations, reasoning, and self-esteem. Three quarters of the patients did not report any alternative explanation for the experiences on which the delusions were based. These patients reported significantly more internal anomalous experiences and had a more hasty reasoning style than patients who did have alternative explanations available. Having doubt in a delusion, without an alternative explanation, was associated with lower self-esteem. Clinicians will need to develop plausible and compelling alternative accounts of experience in interventions rather than merely challenge patients' delusional beliefs.

Adult↗
PubMed2003

Delusions: the continuum versus category debate.

OBJECTIVE: In this paper I critically review the recently developed idea that delusions are best considered as part of a continuum along with more ordinary human beliefs. METHOD: A literature review of the area was guided by a Medline search, and supplemented with material already known to the author. Claims that recent research supports the continuum hypothesis is critiqued. RESULTS: The argument and evidence advanced for the continuum approach to delusions depends largely on: (i) inadequacies of prevailing definitions of delusion, particularly in the light of evidence that delusional conviction is often not absolute; and (ii) the high prevalence of unusual beliefs in community populations. To the extent that the delusion construct contains much in addition to conviction and unusual or false belief content, the continuity approach is weak. The category of delusions continues to have some validity. CONCLUSION: Both categorical and continuous approaches to delusions have validity that depends at any time on our immediate clinical or scientific needs. No definitive resolution of the category versus continuum debate is likely to emerge.

Culture↗
PubMed2002

Bizarre delusions and DSM-IV schizophrenia.

The present study investigated whether schizophrenia patients with and without DSM-IV bizarre delusions, categorized as bizarre delusions of Schneiderian first rank symptoms (SBD) and as non-Schneiderian bizarre delusions (non-SBD), differed on demographic or clinical features, in view of the weight given to bizarre delusions in the diagnosis of schizophrenia. One hundred and twenty-nine in-patients with schizophrenia were assessed systematically for both types of bizarre delusions on the five domains of psychopathology of the Positive and Negative Syndrome Scale (PANSS; delusions/hallucinations, thought disorder/disorganization, excitement, negative symptoms and depressive symptoms) and for extrapyramidal side-effects. Inter-rater reliabilities for SBD and non-SBD were assessed and were exceptionally high (kappa value 0.85 and 0.92, respectively). Neither SBD nor non-SBD were associated with any demographic or non-PANSS clinical characteristics tested. However, the presence of non-SBD was significantly associated with more severe psychopathology in all five domains of the PANSS, whereas the presence of SBD was significantly associated with more severe psychopathology in three domains only: delusions/hallucinations, thought disorder/disorganization and depressive symptoms. However, patients with only SBD did not differ from patients with only non-SBD on any demographic or clinical variables, including five psychopathological domains. These findings suggest that, despite showing more severe symptoms, patients with DSM-IV bizarre delusions do not constitute a clinically distinguishable subgroup.

Adult↗
PubMed1979

A cognitive investigation of schizophrenic delusions.

Delusions have traditionally been regarded as unmodifiable false beliefs. Both Freud (1911) and Jaspers (1968) argue that there is a unidirectional relationship between a delusional belief and consensually validatable realtiy: the delusion structures reality in accordance with the delusion's demand. In contrast, we postulate that there is a bidirectional interaction between the delusion and external events. We believe that external events might modify the rigid belief when there is a dramatic incongruity between specific beliefs and selected events. The following investigation was motivated by a desire to understand more clearly how some overtly delusional patients come to lose their delusions during the course of treatment for schizophrenia. Do delusions simply melt away under the influence of major tranquilizers, or does the delusional patient play some active part in assessing the validity of this belief?

Adult↗
PubMed1997

Delusions of theft in dementia of the Alzheimer type: a preliminary report.

Delusions of theft are commonly found in patients with dementia of the Alzheimer type (DAT). This report describes the frequency, onset, and characteristics of delusions of theft in DAT patients. The sample consisted of 54 geropsychiatric inpatients with DAT; delusions of theft were found in 30 (55.6%) patients. Two thirds of these patients had delusions of theft within 1 year after onset of illness. There were no significant differences in age, age of onset, duration of disease, years of education, or the Mini-Mental State Examination (MMSE) score between patients with and without delusions of theft. Delusions of theft frequently occur in the early stage of dementia, when the patients' cognitive impairments are relatively mild. The presence of this symptom may warrant a diagnosis of DAT.

Aged↗
PubMed2006

Jumping to conclusions and delusion proneness: the impact of emotionally salient stimuli.

The present study investigated whether those who are delusion-prone demonstrate a jumping to conclusions reasoning bias similar to that demonstrated by those with active delusions in previous studies. Two hundred individuals, none of whom had a psychotic disorder, were assessed for delusion-proneness and engaged in two probabilistic reasoning tasks, one emotionally neutral and the other emotionally salient. The emotionally salient task consisted of both positively and negatively valenced personally referent stimuli. Level of delusion-proneness was positively related to jumping to conclusions when stimuli were emotionally salient, though the bias was present only when the first personally referent stimulus was negatively valenced (p < 0.01). Thus, the jumping to conclusions reasoning bias previously demonstrated by individuals who have active delusions appears to be demonstrated under certain conditions by those who are not actively delusional but score high on a measure of delusion-proneness.

Adolescent↗
PubMed1995

Is mythical delusion a factor blocking schizophrenic symptoms?

It has been stated that mythical delusion can block schizophrenic symptoms. However, there are some schizophrenics in whom mythical delusion does not react against schizophrenic symptoms. Three cases are reported of mythical delusion and what conditions are necessary for the mythical delusion to "block" schizophrenic symptoms are considered. Such "blocking' can be found in the mythical delusion which mediates between schizophrenic symptoms and reality. Conversely, when there is no relationship between mythical delusion and schizophrenic symptoms "blocking' cannot be expected.

Adult↗
PubMed1995

Delusions and dementia: clinical and CT correlates.

INTRODUCTION: Delusions occur frequently during the course of Alzheimer's disease (AD) and multi-infarct dementia (MID). Their clinical significance and their relationship with progression of disease and involvement of selected cerebral areas are still unclear. The aim of the study was to determine the clinical and CT correlates of delusions in patients with dementia. MATERIAL AND METHODS: A series of 67 probable AD and 32 MID patients, underwent computed tomographic scans, psychometric tests, neurologic and psychiatric examination, and blood and serum tests. RESULTS: Twenty-four patients were found to have delusions during the clinical evaluation. Delusional patients showed a significantly higher age when compared with non-delusional patients. The results of a multiple logistic regression (with stepwise deletion of the redundant variables) of the CT lesions on the presence of delusions, showed that only the presence of isolated white matter lesions in the frontal lobes were significantly related to the occurrence of delusions (Exp B = 3.42; Beta = 1.2; S.E. = 0.6; Sig T = 0.04). Frontal white matter changes were significantly related to delusions when a multiple regression analysis, entering age and total number of lesions at CT scans, was carried out. CONCLUSIONS: We found that focal lesions in the frontal areas were the only variable that appeared to be significantly and independently associated with delusional disorders.

Activities of Daily Living↗
PubMed1985

A case of hypophyseal prolactinoma with treatable delusions of dermatozoiasis.

The case of an autopsied patient with hypophyseal prolactinoma and dermatozoic delusions is reported, and the mechanism of onset of this special form of delusion is discussed from the neuroendocrinological view point, including response to medications, and neuropathological and pituitary hormonal studies. The subject (69-year-old female) with dermatozoic delusions suffered hypophyseal prolactinoma with high serum prolactin level. Major tranquilizers, minor tranquilizers, or drugs enhancing cerebral blood flow and/or cerebral metabolism did not expell the delusion. Bromocriptine (dopamine agonist) was administered for prolactinoma treatment. After bromocriptine treatment, small doses of haloperidol successfully expelled the delusion. The neuropathological study indicates that the genesis of this delusion is not based on any organic change, but is induced by functional changes related to the prolactin and dopamine systems.

Aged↗
PubMed2005

'Internet delusions': a case series and theoretical integration.

BACKGROUND: Delusions involving the internet have been reported as examples of the influence of cultural innovations on delusion formation, although there has been some debate as to whether such innovations simply affect surface content, or whether they have more substantial clinical or psychopathological implications. SAMPLING AND METHODS: Four cases of patients with delusions involving the internet were identified following a general request to local consultant psychiatrists for referrals. RESULTS: The internet had a specific effect on aetiology in one case, and knowledge of the internet seemed to constrain the type of delusion formed in two others. The presence of an internet-related delusion in the final case was used to frame a successful clinical intervention based on the 'collaborative empiricism' method, using cognitive behavioural therapy and collaborative use of the internet to resolve the delusional belief. CONCLUSIONS: Cultural technical innovations may have specific influences on the form, origin and content of delusional beliefs. For some patients the presence of internet-themed delusions may be a good prognostic indicator since, given the rich sources of information available, they may be well suited to treatment with cognitive behavioural therapy.

Adult↗
PubMed2006

Associations between delusion proneness and personality structure in non-clinical participants: comparison between young and elderly samples.

BACKGROUND: Few studies have explored the prevalence of delusions in the non-clinical, elderly population. In addition, the association between personality structure and delusions remains poorly investigated. The aims of the present study were, first, to explore the relation between age and the prevalence of delusion proneness and, second, to examine the association between personality and delusion proneness in young and elderly participants. SAMPLING AND METHODS: A sample of young (n = 343; aged 18-30 years) and elderly (n = 183; aged 60-75 years) non-clinical participants completed the 21-item version of the Peters et al. Delusions Inventory (PDI-21), an elaborated and validated version of the Launay-Slade Hallucinations Scale, and the revised version of the NEO Personality Inventory (NEO-PI-R). RESULTS: Mean scores on the PDI-21 for the young and elderly participants were compared. An independent t test revealed that the total mean scores were significantly higher for young participants compared to elderly participants. PDI-21 items were then re-grouped into previously validated factors. Independent t tests revealed that young participants had significantly higher scores for items related to suspiciousness and persecutory ideas, thought disturbances and jealousy, grandiose ideas, paranormal beliefs and apocalyptic ideas. In contrast, elderly participants scored significantly higher than young participants on the religious ideation factor. Associations between scores on the NEO-PI-R and the PDI-21 were then examined for the two groups. For the young sample, correlational analyses revealed a significant relationship between the total score on the PDI-21 and scores on the openness, neuroticism and agreeability facets of the NEO-PI-R. For the elderly sample, correlational analyses revealed a significant relationship between the total score on the PDI-21 and the openness facet of the NEO-PI-R. DISCUSSION: Results from the study reveal that delusional ideation is a relatively common experience for both young and elderly non-clinical participants. In addition, findings are in line with studies suggesting that neuroticism and aspects related to neuroticism increase the risk for the development of psychotic symptoms such as delusions. However, it is important to mention that, because the present study includes non-clinical subjects and is a cross-sectional study, more research is needed.

Adolescent↗