The current debate about the diagnostic significance of delusion revolves around two positions. The neurocognitive position conceives delusion as a non-specific, though polymorphic, symptom. The psychopathological position views features of delusion such as content and structure as having meaningful connections with diagnostic entities. This study aims at contributing to this debate by examinin...

In their pursuit of adaptively biased misbelief-making systems, McKay & Dennett (M&D) describe a putative doxastic shear-pin system which enables misbeliefs to form in situations of extreme psychological stress. Rather than discussing their argument, I consider how this shear-pin system might combine with both pathological belief-making (“culpable” breakdowns caused by neuropathy) and normal be...

A multifactorial model of the formation and maintenance of persecutory delusions is presented. Persecutory delusions are conceptualized as threat beliefs. The beliefs are hypothesized to arise from a search for meaning for internal or external experiences that are unusual, anomalous, or emotionally significant for the individual. The persecutory explanations formed reflect an interaction betwee...

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 "...

Patients with delusions exhibit an increased tendency to arrive at decisions based on very limited evidence (jumping-to-conclusions; JTC), making this reasoning bias relevant for the treatment of delusions. Neurocognitive deficits contribute to JTC, but it is not known whether this has any bearing on the clinical syndrome of delusions. We addressed this question by reanalyzing data from an effi...

Delusions are fixed 'false beliefs' and, although a hallmark feature of schizophrenia, no previous study has examined if delusions might be related to 'false memories'. We used the classic Deese-Roediger-McDermott (DRM) paradigm to compare false memory production in schizophrenia patients who were currently experiencing delusions (ED), patients not experiencing delusions (ND) and healthy contro...

The authors reviewed studies published from 1990 to 2001 that address the epidemiology, phenomenology, course, etiology, assessment, and treatment of delusions and hallucinations in Alzheimer's disease. The prevalence of delusions in Alzheimer's disease patients ranged from 16% to 70% (median=36.5%) in the reviewed reports, and the prevalence of hallucinations ranged from 4% to 76% (median=23%)...

A growing literature suggests an association between childhood abusive experiences and psychotic disorders, with some reviewers suggesting that this amounts to a causal relationship (Larkin & Morrison, 2006; Read, van Os, Morrison, & Ross, 2005), though this remains contentious. Estimates from among in-patients (majority with a psychotic diagnosis, Read et al., 2005) suggest that around one-hal...

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...

Delusions are deeply evidence-resistant. Patients with delusions unmoved by evidence that is in direct conflict the delusion, often responding to such offering obvious, and strange, confabulations. As a consequence, standard view not evidence-responsive. This claim has been used as key argumentative wedge debates on nature of delusions. Some have taken be beliefs argued this implies belief cons...