Cognitive approaches to delusions: a critical review of theories and evidence.

“1, and include: Theory of mind (ToM) - the ability to ‘infer intentions, dispositions, and beliefs of others’ [8]; emotion processing - the ability to perceive emotions and interpret them appropriately [9]; social perception - the ability to process social cues and context to decipher social situations [10]; attributi…”

“This is analogous to the overattribution of evidence observed in the JTC bias in the beads task and similar experiments (Freeman et al. 2008; Woodward et al. 2009; Speechley et al. 2010), and is consistent with the observation that people with schizophrenia have poor self-assessment of their own performance and functi…”

“Although a number of cognitive processes have been linked to delusion formation, probabilistic reasoning is perhaps the most robust information-processing bias associated with delusional beliefs (for review, Bell, Halligan, & Ellis, 2006; Garety & Freeman, 1999).”

“In summary, DD cases showed a poorer performance on all memory tasks, including immediate, short and long term memory with large to very large effect sizes, which might be against Garety & Freemans [48] notion that DD patients Jumping to Conclusions (JTC) bias is not a consequence of a memory deficit.”

“Three reasoning anomalies have been of particular interest (see Garety & Freeman, 1999 , for a review).”

“This feature of jumping to conclusions may, as has been hypothesized, be related to delusion onset (Garety and Freeman, 1999).”

“This concurs with the clinically informed notions of delusions as beliefs arising from faulty interpretation of anomalous experiences (Garety and Freeman, 1999) and/or inadequate evidence (Irwin, 2009; Coltheart et al.”

“There are methodological difficulties with assessing implicit self-esteem, as people with persecutory delusions will be motivated to prevent negative self-esteem reaching conscious awareness according to the attribution self-representation model (Garety & Freeman, 1999).”

“Cognitive biases are distortions in the acquisition, processing and interpretation of information, and are implicated in the formation and/or maintenance of delusions (Garety and Freeman, 1999; Moritz et al., 2004; Bell et al., 2006; van der Gaag, 2006).”

“If these individuals also exhibit biased reasoning processes (Garety and Freeman, 1999), low or unstable self-esteem (Ellett et al., 2003; Martin and Penn, 2001; Thewissen et al., 2007), and a proclivity to evaluate others negatively (Chadwick and Trower, 1997), paranoid ideation may be…”

“As to reasoning processes, in their pioneering work Garety and colleagues inscribed their account for delusion in the framework of Bayesian inference, predicting that in a probability judgment task ‘‘people with delusions would make more rapid and overconfident judgments than other clinical and non-clinical controls’’…”

“It is possible, for example, that the JTC bias could lead to the premature acceptance of delusional beliefs (Garety & Freeman, 1999).”

“…with persecutory delusions as they are believed to use less evidence in analyzing social encounters and make decisions without contextual cues; also they present impaired theory of mind (ToM) when inferring the intentions and motivations of others (Garety & Freeman, 1999; Moritz & Woodward, 2005).”

“People who believe in CTs engage in a lot of active searching for confirmatory information and likeminded individuals and tend to dismiss evidence that offers a contrary position (Freeman et al., 2002; Garety & Freeman, 1999; Johnson-Laird, 2006; Leman & Cinnirella, 2013; McHoskey, 1995).”

“A number of recent investigations suggest that PS, in its subclinical and clinical forms, is characterized by a cognitive attentional syndrome (CAS), leading the individual to process information in a biased, reductive, and self-serving fashion (Freeman et al., 2002; Garety and Freeman, 1999).”

“Schizotypal subjects also exhibit increased emotional reactivity to stressors (Myin-Germeys et al., 2001), as well as risk factors such as impaired self-monitoring and reasoning (Garety et al., 1991; Garety and Freeman, 1999), poor sensory integration +1 757 221 3896.”

“It seems possible that symptoms of LOP are the result of an interaction of multiple factors, as has been suggested for psychosis of earlier onset (Garety and Freeman, 1999; Garety et al., 2000).”

“Surprisingly, few studies have focused on this, and current theories of delusions do not address how deluded beliefs might influence autobiographical memory (e.g., Bentall, Kaney, & Dewey, 1991; Garety & Freeman, 1999; Langdon & Coltheart, 2000; Maher, 1974, 1988, 1992; Stone & Young, 1997).”

“Research has shown that deluded individuals draw inferences on the basis of a smaller amount of information (i.e., “jump to conclusions,” JTC) compared to healthy and psychiatric controls (Garety & Freeman, 1999).”

“…in reasoning style, associated with data gathering, as a tendency to accept hypotheses early given that people holding delusional beliefs often demonstrate JTC under conditions of uncertainty on reasoning tasks (Garety and Freeman 1999; Garety and Hemsley 1994; Garety et al. 1991; Huq et al. 1988).”

“, 1997; Parsons and Osherton, 2001) have identified the left DMFC as being activated by inductive reasoning tasks that involve evaluating the plausibility of premise-generated conclusions – an ability that is defective in delusional people (Garety and Freeman, 1999) – but not by deductive reasoning tasks that involve…”

“Typical of this approach have been a number of studies looking at delusions from a cognitive perspective (Garety & Freeman, 1999).”

“In line with this is the increased bias in the perception of those with persecutory delusions registered on the framework of attributional measures, and their tendency to make conclusions based on very little data (jumping to conclusions bias) (see Garety & Freeman, 1999).”

“A previous study reported that people with delusion and schizophrenia show a general reasoning bias called ‘jump-ing to conclusions’ bias (Garety & Freeman, 1999), in which they misattribute the causality of events too easily and too quickly.”

“This jumping to conclusions is neither a function of impulsive decision-making nor a consequence of memory deficit [”

“All rights reserved. doi:10.1016/j.psychres.2007.08.017 conclusions” reasoning bias and to a self-serving attributional bias (e.g., Garety and Freeman, 1999; Bentall et al., 2001).”

“In recent years cognitive models of delusions have been developed suggesting that reasoning biases contribute to the development and maintenance of delusional thinking (Garety and Freeman, 1999; Freeman et al., 2004).”

“By extending the search for psychological mechanisms predictive of specific psychotic symptoms to samples at lower levels of the continuum (Garety and Freeman, 1999) our understanding of psychosis could potentially be enhanced (Johns and van Os, 2001).”

“Subjects are asked to be ‘‘as certain as possible’’, but it is never possible to be completely certain as to which jar the beads have been drawn from [23,30].”

“Patients with delusions show abnormalities and biases in probabilistic reasoning and “jump to conclusions” by making decisions with minimal information (Garety and Freeman, 1999; Garety et al., 2005).”

“This bias may be involved in the development of delusional beliefs in that the individual may consider less evidence and “jump” to a conclusion or explanation that is delusional (Garety & Freeman, 1999 ).”

“Other work has shown, reliably, that patients with schizophrenia show a JTC reasoning bias in probabilistic inference tasks (Averbeck et al., 2011; Garety and Freeman, 1999; Huq et al., 1988).”

“Cognitive models of delusions assume that metamemory biases play a role in the pathogenesis of psychosis, contributing to the emergence and maintenance of positive symptoms (Garety and Freeman, 1999; Garety et al., 2005; Moritz and Woodward, 2006a).”

“‘Jumping to conclusions’ (JTC) reasoning bias refers to a tendency to make decisions based on insufficient information in ambiguous situations [1].”

“Garety and Freeman (1999) found empirical support for JTC, externalizing attributional biases and deficits in understanding social situations and the intentions of others, to be specific biases in these processes (Garety and Freeman, 1999).”

“Factors such as preoccupation with the delusion’s content and increased attentiveness to what are misinterpreted as confirmatory signs in the environment clearly come into play here (Garety and Freeman 1999; Leafhead et al. 1996).”

“Positive symptoms, mostly delusions, are also correlated with low self-esteem and depression (Norman & Malla, 1994 ; Freeman et al. 1998 ; Norman et al. 1998 ; Garety & Freeman, 1999 ; Birchwood et al. 2000 ; Garety et al. 2001; Guillem et al. 2005b).”

“Based on cognitive models (Garety and Freeman, 1999; Freeman, 2016), it has been suggested that the JTC bias is particularly involved in the formation andmaintenance of delusional ideations (Fine et al.”

“Negative self-beliefs are pervasive in patients with paranoia (Collett et al., 2016; Freeman, 2007; Garety and Freeman, 1999).”

“Garety and Freeman [16] argued that individuals with schizophrenia have a data-gathering bias, which may lead to their making hasty decisions that ultimately influence the formation of delusional beliefs.”

“The bias against disconfirmatory evidence (BADE) is thought to be associated with schizophrenic delusions and hypothesized as a possible vulnerability factor for schizophrenia (Freeman et al., 2002; Garety et al., 1991; Garety and Freeman, 1999; Garety et al., 2001).”

“A subtle compensatory response to basic cognitive disturbance demonstrates that even at the first delusional belief formation stage, the influence of other ‘symptoms’ or processes are key (Garety & Freeman, 1999).”

“Cognitive styles such as ‘‘jumping to conclusions’’ and ‘‘externalizing attributional biases’’ are found to be elevated among deluded individuals (Garety & Freeman, 1999), and may therefore influence this appraisal process.”

“…provides information on the normal cognitive processes, for example “jumping to conclusions”, “attribution style” and “selective attention for threat” (Garety and Freeman, 1999), which can lead to the development of psychotic symptoms, may help individuals to cope with their psychosis,…”

“Specifically, individuals ’ appraisal of, and response to (Garety & Freeman, 1999; Peters et al., 2017; Ward, Garety, Jackson, & Peters, 2019), these excessively vivid and intense experiences, which may be mediated by dysregulated dopaminergic signalling (Howes & Murray, 2014; Howes, McCutcheon,…”

“There is also considerable evidence that people prone to delusions jump to conclusions when reasoning (14, 15), at least in the context of binary choice tasks like the one used here (16).”

“Cognitive models of psychosis suggest that dysfunctions in decision-making are involved in the formation and maintenance of positive states of psychosis (Garety & Freeman, 1999).”

“Garety and Freeman (1999) ask whether the reports of ToM deficits are simply a replication of the finding that people with schizophrenia perform poorly on a wide range of cognitive tasks.”

“Garety et al. claimed that their findings indicate that delusional persons formulate probability estimates faster, and with less information, than nondelusional persons. Subsequent studies replicated these findings and also found that the reasoning bias of persons with delusions was not simply a matter of "quick judgm…”

“…formation of delusional ideas, as interpretations which are congruent with the individual’s current emotional state (e.g. paranoia) might be considered likely without proper evaluation of those interpretations (Garety & Freeman, 1999; Moritz & Woodward, 2006a; Speechley, Whitman, & Woodward, 2010).”

“Lack of reflection on the IST is similar to the ‘ jumping to conclusions ’ (JTC) tendency observed in patients with delusions, measured by using a probabilistic reasoning scenario known as the Beads Task (Garety & Freeman, 1999 ; Dudley & Over, 2003 ; Fine et al. 2007).”

“Patients display a premature acceptance of beliefs as true, even when there is limited supporting evidence (Garety & Freeman, 1999; Fine et al. 2007; Ziegler et al. 2008; Lincoln et al. 2010).”

“That delusional and delusion-prone participants “jump to conclusions” on probabilistic reasoning tasks is one of the most robust and important findings in cognitive neuropsychiatry (Colbert & Peters, 2002; Fine et al., 2007; Garety & Freeman, 1999; Huq et al., 1988).”

“However, cognitive models of delusions have highlighted the importance of attribution biases in forming and sustaining persecutory and delusional symptoms (Bentall et al., 1994; Freeman et al., 2002; Garety and Freeman, 1999).”

“Delusional thinking has been the focus of many investigations and theoretical formulations in recent years (for reviews, see Garety and Hemsley, 1994; Bentall and Kinderman, 1998; Garety and Freeman, 1999; Bentall et al., 2001; Fine et al., 2007; Freeman, 2007).”

“As Garety and Freeman [10] have noted, processes such as JTC and BADE, ‘‘may serve as maintaining factors or even consequences of current delusional ideation rather than as causes’’ (p. 148).”