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

“Cognitive theories of delusions provide a link between the biological and phenomenological explanations of delusions (Garety and Freeman, 1999) and might serve as mechanistic explanations of how aberrations in biochemistry seen in schizophrenia could lead to symptomatology.”

“Garety and Freeman (1999) have reported that delusional patients are more likely than controls to switch hypotheses when given potentially contradictory information.”

“For example, research indicates that individuals with persecutory delusions tend to blame others rather than situations for negative events, an attributional style known as a “personalizing bias” (Bentall, Corcoran, Howard, Blackwood, & Kinderman, 2001 ; Garety & Freeman, 1999 ).”

“The cognitive style implicated in such studies has come to be known as the jumping-to-conclusions bias (Garety and Freeman, 1999).”

“Among the most promising approaches are the jumping to conclusions hypothesis (Garety and Freeman, 1999; Huq et al., 1988), the attributional styles hypothesis (e.”

“In the latter two versions, the task is usually terminated after a fixed number of beads (for a review and discussion of these procedures see Garety & Freeman, 1999).”

“With regard to delusions, this phenomenon was called ‘‘jumping to conclusions’’ and was interpreted as an argument for disturbed cognitive processes in the case of (persecutory) delusion (Garety & Freeman, 1999).”

“This way, patients’ impairments in processing implicitly available information may not only underlie attributional biases, but may also reinforce their bias against disconfirmatory evidence (Garety and Freeman, 1999; Penn et al., 2008; Woodward et al., 2006).”

“…acknowledge the important contribution of theorists like Daniel Freeman and Philippa Garety (Freeman, Garety, Kuipers, Fowler, & Bebbington, 2002; Garety & Freeman, 1999, 2013) as well as Richard Bentall (e.g., Bentall, Corcoran, Howard, Blackwood, & Kinderman, 2001) and an early theory by…”

“Jumping to conclusions can also occur in psychosis.(18) Consistent with this, previous work has shown that PDþICB participants score highly on measures of schizotypy, a personality trait related to psychosis.”

“…similar to previous studies, that patients with schizophrenia chose an urn more often on the first draw of the beads task than control subjects (Corcoran et al, 2008; Garety and Freeman, 1999; Garety et al, 1991; Huq et al, 1988; Moritz and Woodward, 2005; Moritz et al, 2007; Van Dael et al, 2006).”

“and promoting insight into illness (Garety et al., 2000; Garety and Freeman, 1999; Morrison, 2001, 2002).”

“The persecutory ideas are most likely to become of a delusional intensity when there are accompanying biases in reasoning such as reduced data gathering (jumping to conclusions; Garety and Freeman, 1999), a failure to generate or consider alternative explanations for experiences (Freeman et al.”

“Many recent reviews attribute cognitive biases a prominent role in the formation and maintenance of delusions, particularly persecutory ideation (Bell, Halligan, & Ellis, 2006; Bentall, Corcoran, Howard, Blackwood, & Kinderman, 2001; Freeman, 2007; Garety & Freeman, 1999; van der Gaag, 2006).”

“past 6 months and no evidence of substance or alcohol abuse in past month, (7) no sedatives or benzodiazepines”

“Increased attention to threatening stimuli, jumping to conclusions, a failure to generate alternatives, theory of mind deficits, problems in emotion perception, and the presence of differences in attributional style have all been associated with persecutory delusions (see Bentall, Corcoran, Howard, Blackwood, & Kinder…”

“Persecutory delusions and the conditioned avoidance paradigm: Towards an integration of the psychology and biology of paranoia Michael Moutoussis”

“Garety and Freeman (1999) conclude that the attributional bias in persecutory delusions is thus most likely a personalising bias: a tendency to blame others for negative events.”

“…of delusions have focused upon perceptual experiences (Maher, 1988), reasoning (Garety & Hemsley, 1994), theory of mind (Frith, 1992), and attributional defences (Bentall, 1994), a direct role for affect, particularly anxiety, has been neglected (see review by Garety & Freeman, 1999).”

“…linking social cognition to severity of various symptoms such as paranoid delusions (Bentall et al. 2009; Lysaker et al. 2009; Martin and Penn, 2002; Peer et al., 2004) as well as negative and/or disorganized symptoms (Garety and Freeman, 1999; Greig et al., 2004; Corcoran et al., 1995b).”

“Impaired belief evaluation processes might include a jumping-to-conclusions bias, as reported in psychiatric deluded patients (Garety & Freeman, 1999 ), an inability to appropriately evaluate conflicting information from the environment or external feedback (Langdon & Coltheart, 2000a ), or the failure of a “discrepan…”

“There have been a number of cognitive theories of delusions (e.g., see Garety & Freeman, 1999; McKenna, 1994).”

“On the other hand, other researchers have advocated for investigating the psychopathology of individual psychotic symptoms (Bentall, Jackson, & Pilgrim, 1988; Garety & Freeman, 1999).”

“Combs, 2009 Current PDs (32); Non-PD delusions (28); Non-clinical (50) EAB; ESE”

“Garety and Freeman (1999) argue the possibility that the jumping to conclusions reasoning bias may play a role in the onset of delusions.”

“A number of theories have been put forward to explain the emergence of delusions, in particular ideas of persecution (for reviews see Bentall, Corcoran, Howard, Blackwood, & Kinderman, 2001; Garety & Freeman, 1999).”

“…cognitive models have variously attempted to explain this through multifactorial impairments to probabilistic reasoning, perception, and affect (Garety & Freeman, 1999); a two-stage impairment to perception and reasoning (Langdon & Coltheart, 2000); aberrations in the use of prediction error…”

“The most replicated finding has been that individuals with delusions tend to gather less evidence before making a decision, a process termed ‘jumping to conclusions’ (see reviews by Fine et al., 2007; Freeman, 2007; Garety and Freeman, 1999).”

“The preponderance of empirical evidence on the JTC bias has been gathered using the probabilistic reasoning task.(4) For this paradigm, 2 jars containing colored beads”

“One of the most commonly studied reasoning paradigms is known as the jumping to conclusions (JTC; Garety et al., 1991; Huq et al., 1988) paradigm, and is widely cited and reviewed (Bell et al., 2006; Blackwood et al., 2001; Davies et al., 2001; Garety and Freeman, 1999).”

“which container the bead sequence is coming from); or the ‘graded estimates’ procedure, where the number of trials is fixed, and for each trial, participants must provide a probability estimate that a particular bead is from one of the two containers (Garety and Freeman, 1999; Moritz and Woodward, 2005).”

“Interestingly, delusional patients ‘jump to conclusions’ in the first version, while they are more willing to revise their decision in light of contradictory evidence in the second (Garety and Freeman, 1999).”

“Second, psychotic symptoms may be associated with feelings of powerlessness and loss of control (Birchwood & Chadwick, 1997 ; Garety & Freeman, 1999 ; Krabbendam & van Os, 2005).”

“The range of delusion scores (1-6) indicated a good spread of symptomatology, with a third of participants scoring above 3, indicating the presence of current delusions.”

“Empirical studies have yielded evidence for cognitive abnormalities in deluded patients (46).”

“These biases appear to be related to the formation and maintenance of symptoms that are characteristic of schizophrenia, particularly delusions (Garety and Freeman, 1999; Freeman, 2007; Moritz and Woodward, 2007).”

“Hospitalization and the change in environment may exacerbate the reasoning bias and tendency to externalization of patients with paranoia and hallucinations (37), inducing in them a particularly intense perception of being coerced.”

“Empirical studies have yielded evidence for cognitive abnormalities in deluded patients [42], particularly, a probabilistic reasoning bias or a ‘jumping to conclusions’ data gathering style [43,44], a selective information processing bias focused at threat-related information [45,46], an abnormal attributional style,…”

“The results concerning the self-protective function of such an attributional style have remained equivocal ( Garety & Freeman, 1999 ), which is partly owing to measurement problems, reflecting an ongoing debate regarding how to assess hidden/implicit self-characterizations.”

“These consist of cognitive biases (Garety & Freeman, 1999) that emerge from underlying “core” beliefs or schemas about the self and world that have become entrenched during an individual’s developmental years.”

“For example, tasks measuring social cognition and reasoning biases have been applied to the study of schizophrenia in order to shed light on the cognitive underpinnings of positive symptoms (Black- wood et al., 2001; Garety and Freeman, 1999).”

“The majority of research has focused on the effect of persecutory delusions on attributional style and cognitive reasoning tasks (Bentall, 2001; Kinderman & Bentall, 1996; Martin & Penn, 2002; see Garety & Freeman, 1999 for a review of this literature).”

“Our results support hypothesis Goldman (1993) that they can better reason about their own mental states than about those of the others.”

“Various studies have linked (meta)cognitive dysfunctions to the formation and maintenance of delusions in schizophrenia (for a review see Bell, Halligan, & Ellis, 2006 ; Freeman, Garety, Kuipers, Fowler, & Bebbington, 2002; Garety & Freeman, 1999 ; van der Gaag, 2006 ).”

“There are at present three general approaches to cognitive accounts of delusion (Garety & Freeman, 1999 ), all of which are concerned primarily with the question of how delusions are formed, rather than why they are retained in the face of conflicting evidence: (1) the “theory of mind” hypothesis, due to Christopher F…”

“…are more likely to reach a delusional intensity if there are accompanying biases in reasoning such as reduced data gathering (jumping to conclusions) (Garety & Freeman, 1999), failure to consider alternative explanations (Freeman et al , 2004) and a strong belief confirmation bias (Wason, 1960).”

“(For a fuller account of the issues see Garety and Freeman 1999; Gerrans, forthcoming) In this paper, I defend a one-stage explanation of the Cotard delusion against a two-stage ac- count developed by Young and Leafhead (1996) of both the Capgras and Cotard delusions.”

“…replicate previous findings showing that people with PDs in the context of schizophrenia spectrum disorders tend to make hasty decisions on probabilistic reasoning tasks (Garety & Freeman, 1999) and have difficulty inferring the beliefs and intentions of others (e.g. Frith & Corcoran, 1996).”

“…have found persons with persecutory delusions to make more external, specifically external-personal attributions for negative events compared to healthy controls there is less evidence for exaggerated internal attributions for positive events (for a critical review see Garety and Freeman 1999).”

“This finding lends support to theories of psychosis, which suggest that delusions are, in part, the cognitive outcomes of individuals’ attempts to explain various anomalous experiences.(26,41,42)”

“” In psychiatric populations, individuals with persecutory delusions typically show a personalizing bias, which is the tendency to blame other people, rather than situational factors, for negative outcomes (Blackwood et al., 2001; Garety and Freeman, 1999).”

“As early as 1999, Garety and Freeman [3] had questioned whether theory of mind deficits are specific to delusions or even to schizophrenia.”

“particular pattern of performance on probabilistic decisionmaking tasks.(45) Rather than, or in addition to, stemming from”

“There have been many proposed theoretical explanations of delusions (for interesting reviews see Blaney, 1999; Garety & Freeman, 1999; Winters & Neale, 1983).”

“…f Cambridge University Press 2009 doi:10.1017/S0033291709005923 Printed in the United Kingdom ORIGINAL ARTICLE dysfunctional styles in the acquisition, processing and appraisal of delusion-neutral information (Garety & Freeman, 1999 ; Bentall et al. 2001 ; Bell et al. 2006 ; van der Gaag, 2006).”

“Yet it has been observed that psychosis itself is a multidimensional experience (Garety and Freeman, 1999; Strauss, 1969), and these different dimensions may respond differentially to treatment (Johnstone et al.”

“…content of a patient’s delusion, MCT targets the cognitive biases (i.e. distortions in the collection and processing of information) thought to underlie the formation and maintenance of delusional beliefs (Bell et al., 2006; Freeman, 2007; Garety and Freeman, 1999; Woodward et al., 2006).”

“Garety and Freeman (1999) express reservations about Kinderman’s interpretation of his results.”

“6 For a review of other accounts, see Garety and Freeman, 1999 .”

“, 2006; Moritz and Woodward, 2006); for example, it has been suggested that theory-of-mind deficits and a jumping-to-conclusions bias might interact to give rise to persecutory delusions in schizophrenia (Garety and Freeman, 1999).”

“The understanding of cognitive processes and biases in schizophrenia has expanded significantly in recent years [5].”

“In addition, the patients show the attribution deficit others have described in patients suffering from schizophrenia, namely that these patients have a tendency to jump to conclusions ( Garety, Freeman, Kuipers, & Fowler, 1999 ).”