Reconceiving delusion

Delusions are critical components in a number of mental disorders, schizophrenia foremost. What are they? The standard view is that they are a type of belief—a pathological belief. Unfortunately, the standard view does not consistently correspond to clinical practice, where the term ‘delusion’ often applies to non-beliefs. We review the case for saying that non-beliefs can count as delusions. We argue that delusions are complexes of higher and lower order attitudes. They constitute a distinctive type of failure of self-knowledge and self-management. We describe the relevant type. One of the conceptual implications of our view is that beliefs need not be central to delusions.     

Delusions as Forensically Disturbing Perceptual Inferences

Bortolotti’s Delusions and Other Irrational Beliefs defends the view that delusions are beliefs on a continuum with other beliefs. A different view is that delusions are more like illusions, that is, they arise from faulty perception. This view, which is not targeted by the book, makes it easier to explain why delusions are so alien and disabling but needs to appeal to forensic aspects of functioning.     

Delusions or obsessions: the same only different? A case report

The phenomenological distinction between delusions and obsessions has been the subject of much debate in psychiatry. Some authors feel these symptoms are distinct nosological entities, while others argue that they reflect manifestations of the same symptom and are distinguishable on the basis of the level of insight a patient displays. In this report we describe the case history of a lady who presented with an obsessional disorder. The symptom was resistant to standard treatments and subsequently became more delusional in nature. We review the literature in terms of the classification of obsessions and delusions and offer assistance to clinicians in terms of the diagnosis and treatment of cases where the distinction between these phenomena is not clear and offer alternative means of classifying these symptoms based on insight.     

Schizophrenia and monothematic delusions

Numerous delusions have been studied which are highly specific and which can present in isolation in people whose beliefs are otherwise entirely unremarkable - "monothematic delusions" such as Capgras or Cotard delusions. We review such delusions and summarize our 2-factor theory of delusional belief which seeks to explain what causes these delusional beliefs to arise initially and what prevents them being rejected after they have arisen. Although these delusions can occur in the absence of other symptoms, they can also occur in the context of schizophrenia, when they are likely to be accompanied by other delusions and hallucinations. We propose that the 2-factor account of particular delusions like Capgras and Cotard still applies even when these delusions occur in the context of schizophrenia rather than occurring in isolation.     

Socially naïve self-appraisal moderates the relationship between cognitive insight and positive symptoms in schizophrenia

Cognitive insight refers to awareness of one's own thinking. Research has found deficits in cognitive insight in schizophrenia but studies of its links with positive symptoms and delusions have been equivocal. One possibility is that the association of cognitive insight with positive symptoms and delusions is moderated by other factors. To explore this issue this study examined whether level of socially naive self-appraisal moderated the relationship of two forms of cognitive insight, self-reflectivity and self-certainty with delusions and positive symptoms. Participants were 92 adults, with diagnoses of schizophrenia or schizoaffective disorder, who were administered the Positive and Negative Syndrome Scale, self-deceptive subscale from the Marlowe–Crowne Social Desirability Scale and the Beck Cognitive Insight Scale. Stepwise multiple regressions with the interaction term of the predictive and moderator variables suggested that social naiveté moderates the relationship between self-reflectivity and self-certainty with positive symptoms in general. Moreover, association between self-certainty and delusions was also moderated by social naiveté self-appraisal. All models were significant after controlling for willful impression management as well as a measure of executive function. Results suggest that higher levels of self-certainty are a risk factor for having greater positive symptoms including more severe levels of delusions, when one has a view of oneself that is not tempered by the perceptions of others. Concerning lower levels of self-reflectivity it may be that this combined with a socially naïve view of oneself leaves persons less inhibited when they are tempted to accept unusual thoughts and perceptions as accurate. Implications for treatment are discussed.     

Cotard's syndrome: analysis of 100 cases

In 1880, Jules Cotard reported a clinical state he believed was a new type of agitated melancholia. A statistical analysis has been carried out of 100 cases of Cotard's syndrome to determine how this clinical concept has fared since its inception. In terms of clinical profile, no difference was found between men and women or between underlying diagnostic categories; age seemed to increase the likelihood of developing délire des négations. Depression was reported in 89% of subjects; the most common nihilistic delusions concerned the body (86%) and existence (69%). Anxiety (65%) and guilt (632) were also common, followed by hypochondriacal delusions (58%) and delusions of immortality (55). An exploratory factor analysis extracted 3 factors: psychotic depression, Cotard type I and Cotard type II. The psychotic depression factor included patients with melancholia and few nihilistic delusions. Cotard type I patients, on the other hand, showed no loadings for depression or other disease and are likely to constitute a pure Cotard syndrome whose nosology may be closer to the delusional than the affective disorders. Type II patients showed anxiety, depression and auditory hallucinations and constitute a mixed group. This new grouping cuts across the more traditional view and may have therapeutic implications. Authors, in general, have considered délire des négutions as a syndrome rather than a new disease and do not seem to support the view that the completeness of the syndrome is a function of presence or severity of depression. The view that délire des négutions refers only to the delusion of being dead has also curried little favour as it is likely to waste information.     

Chronic Koro-like Syndrome (KLS) in recurrent depressive disorder as a variant of Cotard's delusion in an italian male patient. A case report and historical review

Cotard’s syndrome is a delusional syndrome, first described in the 1880ies by Cotard, characterized by a nihilistic delusions about the self and/or the world. In same other cases there is an intense nihilistic belief that the patient’s entire body or parts of it are disintegrated or dead. The syndrome is often associated with severe depression, but are also described neurological cases. Koro was described a little later from Asia and consisted in the belief that one’s own genitalia are shrinking or disappearing and death will ensue thereafter, but there are many cultural variants and the syndrome may present in an incomplete form. We report on a KLS sharing more features with annihilation delusions, such as Cotard’s syndrome. In KLS, the délire de négation may be limited to localized systems or organs. We believe that some complete and incomplete forms of Koro, when embedded in a depressive core, may represent a variant of Cotard’s delusion. In fact, our patient did not reach a complete denial of his entire body, but rather focused on sexual identity. We analysed the psychosexual issues of our case according to Kretschmer’s 1918 view of a “bipolar setting” between sthenic and asthenic characters of a patient suffering from sensitive delusions of (self-) reference. This view may allow us to relate the personological character to the genetic comprehensibility of the delusion.     

Religious delusions in patients admitted to hospital with schizophrenia

Background Religious delusions are clinically important because they may be associated with selfharm and poorer outcomes from treatment. They have not been extensively researched. This study sought to investigate the prevalence of religious delusions in a sample of patients admitted to hospital with schizophrenia, to describe these delusions and to compare the characteristics of the patients with religious delusions with schizophrenia patients with all other types of delusion. Method A cross-sectional investigation was carried out. The prevalence of religious delusions was assessed and comparisons were made between religiously deluded patients and a control group on demographic, symptom, functioning and religious variables. One hundred and ninety-three subjects were examined of whom 24% had religious delusions. Results Patients with religious delusions had higher symptom scores (as measured by the PANSS), they were functioning less well (as measured by the GAF) and they were prescribed more medication than those patients with schizophrenia who had other types of delusion. Conclusion It is concluded that religious delusions are commonly found in schizophrenia and that by comparison with other patients who have schizophrenia, those patients with religious delusions appear to be more severely ill. This warrants further investigation. Accepted: 15 November 2001     

Misattribution of external speech in patients with hallucinations and delusions

BACKGROUND: One of the main cognitive models of positive symptoms in schizophrenia proposes that they arise through impaired self-monitoring. This is supported by evidence of behavioural deficits on tasks designed to engage self-monitoring, but these deficits could also result from an externalising response bias. We examined whether patients with hallucinations and delusions would demonstrate an externalising bias on a task that did not involve cognitive self-monitoring. METHOD: Participants passively listened (without speaking) to recordings of single adjectives spoken in their own and another person's voice, and made self/nonself judgements about their source. The acoustic quality of recorded speech was experimentally manipulated by altering the pitch. Fifteen patients with schizophrenia who were currently experiencing hallucinations and delusions, 13 patients with schizophrenia not experiencing current hallucinations and delusions and 15 healthy controls were compared. RESULTS: When listening to distorted words, patients with hallucinations and delusions were more likely than both the group with no hallucinations and delusions and the control group to misidentify their own speech as alien (i.e. spoken by someone else). Across the combined patient groups, the tendency to misidentify self-generated speech as alien was positively correlated with current severity of hallucinations but not with ratings of delusions or positive symptoms in general. CONCLUSIONS: These findings indicate that patients with hallucinations and delusions are prone to misidentifying their own verbal material as alien in a task which does not involve cognitive self-monitoring. This suggests that these symptoms are related to an externalising bias in the processing of sensory material, and not solely a function of defective self-monitoring.     

In Defence of Modest Doxasticism About Delusions

Here I reply to the main points raised by the commentators on the arguments put forward in my Delusions and Other Irrational Beliefs (OUP, 2009). My response is aimed at defending a modest doxastic account of clinical delusions, and is articulated in three sections. First, I consider the view that delusions are in-between perceptual and doxastic states, defended by Jacob Hohwy and Vivek Rajan, and the view that delusions are failed attempts at believing or not-quite-beliefs, proposed by Eric Schwitzgebel and Maura Tumulty. Then, I address the relationship between the doxastic account of delusions and the role, nature, and prospects of folk psychology, which is discussed by Dominic Murphy, Keith Frankish, and Maura Tumulty in their contributions. In the final remarks, I turn to the continuity thesis and suggest that, although there are important differences between clinical delusions and non-pathological beliefs, these differences cannot be characterised satisfactorily in epistemic terms.     

The incubus syndrome. A variant of erotomania.

The term "incubus syndrome" is proposed to describe patients suffering from the delusion that they have been sexually approached at night by an unseen lover. Two cases characterized by co-existence of erotomania and schizophrenic sexual delusions are described. The patient's behaviour secondary to the defusion is discussed from the point of view of social significance as well as potential dangerousness.     

Violence and delusions: data from the MacArthur Violence Risk Assessment Study

OBJECTIVE: Previous work has suggested that delusions are associated with a higher risk of violence, particularly delusions in which patients believe that people are seeking to harm them or that outside forces are controlling their minds (denoted as "threat/control override" delusions). This study explores the relationship between delusions and violence among patients recently discharged from acute psychiatric hospitalization. METHOD: Data were drawn from the MacArthur Violence Risk Assessment Study, a study of violence in the community that followed 1,136 recently discharged psychiatric patients for 1 year. Interviews at discharge and at five 10-week intervals gathered clinical, historical, situational, and dispositional information, including the presence and nature of delusional thoughts. Violence was ascertained from reports of subjects, collateral informants, and official records. RESULTS: Neither delusions in general nor threat/control override delusions in particular were associated with a higher risk of violent behavior. Comparisons with prior studies suggest that reliance on subject self-reports of delusional symptoms may result in mislabeling as delusions other phenomena that can contribute to violence. CONCLUSIONS: Although delusions can precipitate violence in individual cases, these data suggest that they do not increase the overall risk of violence in persons with mental illness in the year after discharge from hospitalization.     

The meanings of delusions in dementia: a preliminary study

One of the common symptoms of dementia is delusions. Due to a biological conceptualization of the behaviors represented as delusions, these are classified as psychotic symptoms. This is a qualitative and quantitative study aiming to describe the delusions experienced by older persons with dementia and the context of occurrence, and to elucidate their etiology. Participants were 74 nursing home residents aged 65 and over, diagnosed with dementia, from nine nursing homes in Israel. Participants with delusions were found to have significantly more difficulties in performing ADLs, and poorer vision and hearing. Based on assessment using the BEHAVE-AD, six categories of delusions were examined: 1. One's house is not one's home, 2. Theft, 3. Danger, 4. Abandonment, 5. Misidentification, and 6. Other non-paranoid. Common themes appeared across delusions including reality, disorientation, re-experience of past events, loneliness and insecurity, boredom, and trigger. Current results suggest that delusions may not represent psychotic symptoms for most participants, because they sometimes represented reality, or were neither firm nor incontrovertible. Thus, utilizing the term delusion relegates the person's behavior to the domain of severe psychiatric phenomena and precludes understanding its true meaning.     

Persecutory delusions in dementia.

BACKGROUND: Persecutory delusions are common in dementia. This study was undertaken to investigate the prevalence, associated factors, and characteristics of persecutory delusions in demented patients. METHOD: The sample population included 167 demented patients (DSM-III-R criteria) admitted to a geropsychiatric ward. Patients were assessed for the occurrence of any persecutory delusions since the onset of dementia. The content of persecutory delusions, the patients' response to the delusions, and any concomitant psychiatric symptoms were also explored. RESULTS: Of the 167 demented patients, 45 (26.9%) showed symptoms of persecutory delusions. Patients with persecutory delusions had a higher prevalence of other delusions, hallucinations, and physically aggressive behaviors. The deluded patients often thought that their caregivers were their persecutors and had a wide range of responses to their delusions. After they were hospitalized, many of these patients attacked medical staff and were uncooperative with treatment. CONCLUSION: Persecutory delusions are common in dementia of various types. Deluded patients often have vigorous responses to their delusions including physically aggressive behaviors and suicide attempts. Careful evaluation is needed to assess the potential for violent and suicidal behaviors in these patients. Medical staff should be alert to clinical strategies for handling the treatment of such patients when they become violent or uncooperative.     

Deficits in sensory prediction are related to delusional ideation in healthy individuals

Motor control strongly relies on neural processes that predict the sensory consequences of self-generated actions. Previous research has demonstrated deficits in such sensory-predictive processes in schizophrenic patients and these low-level deficits are thought to contribute to the emergence of delusions of control. Here, we examined the extent to which individual differences in sensory prediction are associated with a tendency towards delusional ideation in healthy participants. We used a force-matching task to quantify sensory-predictive processes, and administered questionnaires to assess schizotypy and delusion-like thinking. Individuals with higher levels of delusional ideation showed more accurate force matching suggesting that such thinking is associated with a reduced tendency to predict and attenuate the sensory consequences of self-generated actions. These results suggest that deficits in sensory prediction in schizophrenia are not simply consequences of the deluded state and are not related to neuroleptic medication. Rather they appear to be stable, trait-like characteristics of an individual, a finding that has important implications for our understanding of the neurocognitive basis of delusions.     

The Folk Epistemology of Delusions

Lisa Bortolotti argues convincingly that opponents of the doxastic view of delusion are committed to unnecessarily stringent standards for belief attribution. Folk psychology recognises many non-rational ways in which beliefs can be caused, and our attributions of delusions may be guided by a sense that delusions are beliefs that we cannot explain in any folk psychological terms.     

Alteration of rCBF in Alzheimer's disease patients with delusions of theft

We investigated the neural substrate of the delusion of theft in patients with Alzheimer's disease (AD). Nine AD patients with only one type of delusion (delusions of theft) and nine age, cognitive function-matched AD patients without any type of delusions were selected from 334 consecutive outpatients of Ehime University Hospital. All subjects underwent (99m)Tc-HMPAO SPECT scanning, and SPECT images were analyzed by Statistical Parametric Mapping (SPM). AD patients with delusions of theft showed significant hypoperfusion in the right medial posterior parietal region compared to patients without delusions. Our data suggest that attention impairment or lack of awareness of illness caused by right parietal dysfunction might play a role in producing the delusion of theft.     

Symptom onset and involution of delusions

Summary The fate of delusions was studied in schizophrenics and other paranoid psychotics with a view to determining the relation between the outcome of delusions and mode of onset and the variables affecting both. Involution of delusions may be effected through their disappearance into the system of socially shared delusory cultural beliefs or their metamorphosis into less sinister symptoms e. g. dreams, fantasies or ruminations. Patients presenting with subjective suffering fared best and had an over-representation of those living in extended families. The culturally shared belief system provides a container for delusions that lose their pathological quality and content. The roles of literacy and prolonged residence abroad on the contents and modes of expression of delusions is discussed.     

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.     

The relationship between delusions and hallucinations

The origins of delusional beliefs have been a question of great interest for centuries. For many years, the widely held view was that there was a fundamental defect in reasoning in the patient that gave rise to the false belief. Much effort was directed at establishing the kind of defect and the circumstances that triggered it. The search for the basic reasoning defect has met with limited success, mainly because the flaws found in the reasoning of deluded persons are also found with substantial frequency in the general population. The co-occurrence of hallucinations and delusions is consistent with findings that repeated anomalous experiences of various kinds are followed by the development of delusions. In this case, it would be reasonable to regard the hallucinations as exercising a causative role in the development of delusions.