Peters Delusions Inventory Research Articles

Blindness of intentions and metacognitive deficits during moral judgements in schizophrenia.

Previous research has shown that moral judgments are affected by social cognitive abilities, such as theory of mind (ToM). This study examines how information about an actor's beliefs and the consequences of their actions affect the moral evaluation of the character's behavior in social events. Our research builds upon previous studies, which have shown that these factors contribute differently to moral judgments made by both adults and young children. This study aimed to explore how participants with schizophrenia and healthy controls read stories about social situations in the context of moral judgments. The study used the research procedure that included 4 variants of 16 scenarios describing social situations, and thus comprising 64 stories. After each story, participants evaluated their confidence level on a 4-point scale. To assess delusional beliefs, the Polish adaptation of the Peters Delusion Inventory (PDI) questionnaire and the Paranoia Checklist (PCh) were used. Respondents completed these questionnaires after completing the scenario test procedure. In social situations, patients with paranoid schizophrenia were found to evaluate actions of protagonists who attempted to harm another person more leniently than when it was an accident. Conversely, healthy individuals judged those actors who expressed intentions to hurt another person significantly more harshly than in an accident situation. Metacognition measures show that paranoid schizophrenia patients make moral judgments with high confidence, despite being based on an incorrect reading of the other person's intentions. The study indicates that ToM has a significant impact on the moral judgment of others. Decreased moral cognition can result from both positive and negative symptoms. Deficits related to metacognition can also sustain such cognitive distortions.

Profiles in conspiracism: Associations with two psychiatric syndromes, religiosity and pandemic-related health behaviors.

Conspiratorial beliefs are often maladaptive for individuals and dangerous for societies. Other prevalent belief systems such as (normative) religious belief and (pathological) delusional belief show parallels to conspiratorial beliefs, which may also be linked to excessive social media exposure. We conducted an online survey to characterize heterogeneous profiles of conspiracy-mindedness, with respect to these other phenomena. Eight hundred and thirty six American adults from online panels completed validated questionnaires including the Conspiracy Mindedness Questionnaire (CMQ), Centrality of Religion Scale (CRS), Peters Delusion Inventory (PDI; 21-item version), and Facebook Addiction Scale (FAS). Additionally, they completed 4 questions addressing categorical belief in the origin of SARS-CoV-2, and pandemic-related health behaviors. Total scores on each questionnaire were Z-transformed and entered into K-means cluster analysis. Cluster membership was used in post-hoc analyses to compare pandemic-related items. An optimal solution included 3 clusters with above-mean (high) CMQ and 3 below-mean (low) CMQ scores. The 3 high-CMQ clusters included: (1) high-religion, low-social media addiction; (2) high religion, social media addiction and delusion; (3) low religion and delusion. High-CMQ clusters 1 and 2 each had rates of zoonotic and malevolent viral origin beliefs that were relatively lower and higher than the grand sample rates, respectively. Significant differences in intended pandemic health-related behaviors among the high-CMQ clusters (compared to the rest of the sample) included Cluster 1-high on Precautions and low on Vaccination; Cluster 2-high on Testing. Respondents who endorsed SARS-CoV-2 origin beliefs (across clusters) that were least plausible and most malevolent were least inclined to engage in pandemic health behaviors. Distinct subpopulations of persons with high conspiracy-mindedness exist, which are highly heterogeneous in their other coexisting beliefs and behaviors. Some of these may be pathological, such as delusional belief and social media addiction-like behavior, and they have varied associations with pandemic-related belief and behavior. These results, while cross-sectional, suggest that the psychological origins and consequences of conspiratorial beliefs may not be unitary. Instead, conspiratorial belief may be a common expression of diverse psychological and social/experiential factors, and in turn exert varied influence on decisions and overt behavior.

Experimental Sleep Deprivation Results in Diminished Perceptual Stability Independently of Psychosis Proneness.

Psychotic disorders as well as psychosis proneness in the general population have been associated with perceptual instability, suggesting weakened predictive processing. Sleep disturbances play a prominent role in psychosis and schizophrenia, but it is unclear whether perceptual stability diminishes with sleep deprivation, and whether the effects of sleep deprivation differ as a function of psychosis proneness. In the current study, we aimed to clarify this matter. In this preregistered study, 146 participants successfully completed an intermittent version of the random dot kinematogram (RDK) task and the 21-item Peters Delusion Inventory (PDI-21) to assess perceptual stability and psychosis proneness, respectively. Participants were randomized to sleep either as normal (8 to 9 h in bed) (n = 72; Mage = 24.7, SD = 6.2, 41 women) or to stay awake through the night (n = 74; Mage = 24.8, SD = 5.1, 44 women). Sleep deprivation resulted in diminished perceptual stability, as well as in decreases in perceptual stability over the course of the task. However, we did not observe any association between perceptual stability and PDI-21 scores, nor a tendency for individuals with higher PDI-21 scores to be more vulnerable to sleep-deprivation-induced decreases in perceptual stability. The present study suggests a compromised predictive processing system in the brain after sleep deprivation, but variation in psychosis trait is not related to greater vulnerability to sleep deprivation in our dataset. Further studies in risk groups and patients with psychosis are needed to evaluate whether sleep loss plays a role in the occurrence of objectively measured perceptual-related clinical symptoms.

Relationships among subclinical psychotic symptoms in young adults over time

BackgroundSubclinical psychotic symptoms are common in the general population and are often benign. However, those that become distressing or persistent may increase risk for the development of a psychotic disorder. Cognitive models have proposed that certain appraisals of hallucinatory experiences can lead to delusional beliefs, particularly if an individual is experiencing negative mood. However, the dynamic relationships among these symptoms are poorly understood. This study examined the longitudinal relationships among subclincal hallucinations, delusional ideation, and depression in a sample of young adults. Methods677 college students completed baseline questionnaires to assess: delusional ideation (Peters Delusions Inventory), hallucinations (Launay-Slade Hallucinations Scale-Extended), and depression (Beck Depression Inventory). These measures were repeated 7, 13, 19, and 25 months later. ResultsHigher baseline severity of hallucinations was strongly predictive of severity of delusions across all future follow-up timepoints, specifically when baseline depression was high. However, the severity of hallucinations did not change over time, nor were they predicted by baseline delusional ideation. ConclusionsThese findings support the proposal that hallucinations frequently precede more severe delusional ideation, rather than the reverse sequence, particularly when depressive symptoms are present. Such longitudinal relationships provide clues to the underlying mechanisms of psychosis, highlighting one pathway for intervention.

Investigating predictors contributing to the expression of schizotypy during the COVID-19 pandemic

The coronavirus (COVID-19) pandemic has caused major disruptions to social and other forms of functioning, which may influence schizotypy expression. The current study aimed to explore possible distal and proximal predictors contributing to schizotypy in a sample of the Australian general population during the COVID-19 pandemic. The COvid-19 and you: mentaL heaLth in AusTralia now survEy (COLLATE) project is an online mental health study aimed at tracking key mental health indicators over the progression of the pandemic. Adults residing in Australia were invited to take part using non-discriminative snowball sampling. Demographic-clinical information was collected for 850 participants in either October 2020 or January 2021. To assess schizotypy facets, the Launay-Slade Hallucinations Scale-Extended (LSHS-E) and Peters Delusions Inventory (PDI-21) were used to measure hallucination and delusion proneness respectively. Generalised linear models (with gamma and negative binomial distributions) were employed. Age, negative emotions and loneliness significantly contributed to both hallucination and delusion proneness; gender, education and religiosity also significantly contributed to delusion proneness, in the final regression models. Our study corroborated the specific contribution of loneliness, amongst other factors, in the prediction of schizotypy facets. Tackling loneliness represents a public health challenge that needs to be urgently addressed, especially in the face of the ongoing COVID-19 pandemic.

The over-estimation of distance for self-voice versus other-voice

Self-related stimuli are important cues for people to recognize themselves in the external world and hold a special status in our perceptual system. Self-voice plays an important role in daily social communication and is also a frequent input for self-identification. Although many studies have been conducted on the acoustic features of self-voice, no research has ever examined the spatial aspect, although the spatial perception of voice is important for humans. This study proposes a novel perspective for studying self-voice. We investigated people’s distance perception of their own voice when the voice was heard from an external position. Participants heard their own voice from one of four speakers located either 90 or 180 cm from their sitting position, either immediately after uttering a short vowel (i.e., active session) or hearing the replay of their own pronunciation (i.e., replay session). They were then asked to indicate which speaker they heard the voice from. Their voices were either pitch-shifted by ± 4 semitones (i.e., other-voice condition) or unaltered (i.e., self-voice condition). The results of spatial judgment showed that self-voice from the closer speakers was misattributed to that from the speakers further away at a significantly higher proportion than other-voice. This phenomenon was also observed when the participants remained silent and heard prerecorded voices. Additional structural equation modeling using participants’ schizotypal scores showed that the effect of self-voice on distance perception was significantly associated with the score of delusional thoughts (Peters Delusion Inventory) and distorted body image (Perceptual Aberration Scale) in the active speaking session but not in the replay session. The findings of this study provide important insights for understanding how people process self-related stimuli when there is a small distortion and how this may be linked to the risk of psychosis.

Association Between Failures in Perceptual Updating and the Severity of Psychosis in Schizophrenia

Recent accounts suggest that delusions and hallucinations may result from alterations in how prior knowledge is integrated with new information, but experimental evidence supporting this idea has been complex and inconsistent. Evidence from a simpler perceptual task would make clear whether psychotic symptoms are associated with overreliance on prior information and impaired updating. To investigate whether individuals with schizophrenia or schizoaffective disorder (PSZ) and healthy control individuals (HCs) differ in the ability to update their beliefs based on evidence in a relatively simple perceptual paradigm. This case-control study included individuals who met DSM-IV criteria for PSZ and matched HC participants in 2 independent samples. The PSZ group was recruited from the Maryland Psychiatric Research Center, Yale University, and community clinics, and the HC group was recruited from the community. To test perceptual updating, a random dot kinematogram paradigm was implemented in which dots moving coherently in a single direction were mixed with randomly moving dots. On 50% of trials, the direction of coherent motion changed by 90° midway through the trial. Participants were asked to report the direction perceived at the end of the trial. The Peters Delusions Inventory and Brief Psychiatric Rating Scale (BPRS) were used to quantify the severity of positive symptoms. Data were collected from September 2018 to March 2020 and were analyzed from approximately March 2020 to March 2021. Critical measures included the proportion of responses centered around the initial direction vs the subsequent changed direction and the overall precision of motion perception and reaction times. A total of 48 participants were included in the PSZ group (31 [65%] male; mean [SD] age, 36.56 [9.76] years) and 36 in the HC group (22 [61%] male; mean [SD] age, 35.67 [10.74] years) in the original sample. An independent replication sample included 42 participants in the PSZ group (29 [69%] male; mean [SD] age, 33.98 [11.03] years) and 34 in the HC group (20 [59%] male; mean [SD] age, 34.29 [10.44] years). In line with previous research, patients with PSZ were less precise and had slower reaction times overall. The key finding was that patients with PSZ were significantly more likely (original sample: mean, 27.88 [95% CI, 24.19-31.57]; replication sample: mean, 26.70 [95% CI, 23.53-29.87]) than HC participants (original sample: mean, 18.86 [95% CI, 16.56-21.16]; replication sample: mean, 15.67 [95% CI, 12.61-18.73]) to report the initial motion direction rather than the final one. Moreover, the tendency to report the direction of initial motion correlated with the degree of conviction on the Peters Delusions Inventory (original sample: r = 0.32 [P = .05]; replication sample: r = 0.30 [P = .05]) and the Brief Psychiatric Rating Scale Reality Distortion score (original sample: r = 0.55 [P = .001]; replication sample: r = 0.35 [P = .03]) and severity of hallucinations (original sample: r = 0.39 [P = .02]; replication sample: r = 0.30 [P = .05]). The findings of this case-control study suggest that the severity of psychotic symptoms is associated with a tendency to overweight initial information over incoming sensory evidence. These results are consistent with predictive coding accounts of the origins of positive symptoms and suggest that deficits in very elementary perceptual updating may be a critical mechanism in psychosis.

A cognitive model of delusion propensity through dysregulated correlation detection

BackgroundWe present a novel account of delusion propensity that integrates the roles of working memory (WM), decision criteria, and information gathering biases. This framework emphasises the role of aberrant correlation detection, which leads to the spurious perception of relationships between one's experiences. The frequency of such outcomes is moderated by the scaling of one's decision criteria which, for reasons discussed, must also account for WM capacity. The proposed dysregulated correlation detection account posits that propensity for delusional ideation is influenced by disturbances in this mechanism. MethodsHypotheses were tested using a novel task that required participants (N = 92) to identify correlation between binary manipulations of simple shapes, presented as sequential pairs. Decision criteria and correlation detection were assessed under a Signal Detection Theory framework, while WM capacity was assessed through the Automated Operation Span Task and delusion propensity was measured using the Peters Delusion Inventory. Structural equation modeling was conducted to evaluate the proposed model. ResultsConsistent with the central hypothesis, an interaction between decision criteria and WM was found to contribute significantly to delusion propensity through its effect on correlation detection accuracy. Greater delusion propensity was observed among participants with more liberal decision criteria, which was also in accordance with hypotheses. At the same time, the total effect of WM on delusion propensity was not found to be significant. ConclusionsThese findings provide preliminary support for the proposed dysregulated correlation detection account of propensity for delusional ideation.

Paranoia and Grandiosity in the General Population: Differential Associations With Putative Causal Factors.

Worry, negative self-beliefs, and sleep disturbance have been identified as contributory factors to the onset, maintenance, and severity of paranoia. We tested the specificity of these contributory factors to paranoia compared to grandiosity, a different type of delusional ideation. Data were used from 814 adults from the Nathan Kline Institute-Rockland (NKI-Rockland) study, a general population dataset. Paranoid and grandiose delusional ideation was assessed using the Peters Delusions Inventory (PDI-21) and correlated with self-reported worry (n = 228), negative self-beliefs (n = 485), and sleep quality (n = 655). Correlations were compared using Fisher's r-to-z transform to examine whether the magnitude of relationships differed by delusion type. Paranoia was significantly associated with worry, negative self-belief, and sleep quality. Grandiosity demonstrated significantly weaker relationships with worry and negative self-beliefs. Relationships with sleep quality were similar. We replicate previous reports that worry, negative self-beliefs and sleep quality are associated with paranoid ideation in the general population. We extend these findings by demonstrating that these contributory factors, particularly worry and negative self-beliefs, are associated with paranoid ideation to a greater extent than grandiosity. This suggests a degree of specificity of contributory factors to different types of delusional thinking, supporting the pursuit of specific psychological models and treatments for each delusion type.

Relationship between cannabis use and psychotic experiences in college students

BackgroundEmerging data suggest cannabis use is a component cause of psychotic disorders; however, the sequence of processes accounting for this association is poorly understood. Some clues have come from studies in laboratory settings showing that acute cannabis intoxication is associated with subclinical hallucinations and delusional thinking, i.e., “psychotic experiences”. Although psychotic experiences are relatively common, those that are severe and distressing are linked to an increased risk of developing a psychotic disorder. This study aimed to investigate the association between the frequency of cannabis use and psychotic experiences in young adults. Methods1034 U.S. college students completed questionnaires to assess: cannabis use in the past week, delusional ideation (Peters Delusions Inventory), hallucinations (Launay-Slade Hallucinations Scale-Extended), and depression (Beck Depression Inventory). ResultsParticipants reporting higher rates of weekly cannabis use were more likely to report hallucinatory experiences and delusional ideation. The relationship between cannabis use and hallucinatory experiences, but not the relationship between cannabis use and delusional ideation, remained significant after controlling for levels of depression. Moreover, those who reported greater amounts of cannabis use had more distressing delusional ideas, that were held with more conviction. ConclusionsCannabis use is linked to the presence of subclinical hallucinations and delusional ideation in U.S. college students.

Cognitive Biases Questionnaire for Psychosis (CBQp): Spanish Validation and Relationship With Cognitive Insight in Psychotic Patients.

Introduction: Cognitive biases are key factors in the development and persistence of delusions in psychosis. The Cognitive Biases Questionnaire for Psychosis (CBQp) is a new self-reported questionnaire of 30 relevant situations to evaluate five types of cognitive biases in psychosis. In the context of the validation of the Spanish version of the CBQp, our objectives were to (1) analyze the factorial structure of the questionnaire with a confirmatory factor analysis (CFA), (2) relate cognitive biases with a widely used scale in the field of delusion cognitive therapies for assessing metacognition, specifically, Beck's Cognitive Insight Scale (BCIS) (1), and, finally, (3) associate cognitive biases with delusional experiences, evaluated with the Peters Delusions Inventory (PDI) (2).Materials and Methods: An authorized Spanish version of the CBQp, by a translation and back-translation procedure, was obtained. A sample of 171 patients with different diagnoses of psychoses was included. A CFA was used to test three different construct models. Associations between CBQp biases, the BCIS, and the PDI were made by correlation and mean differences. Comparisons of the CBQp scores between a control group and patients with psychosis were analyzed.Results: The CFA showed comparative fit index (CFI) values of 0.94 and 0.95 for the models with one, two, and five factors, with root mean square error of approximation values of 0.031 and 0.029. The CBQp reliability was 0.87. Associations between cognitive biases, self-certainty, and cognitive insight subscales of the BCIS were found. Similarly, associations between total punctuation, conviction, distress, and concern subscales of the PDI were also found. When compared with the group of healthy subjects, patients with psychoses scored significantly higher in several cognitive biases.Conclusion: Given the correlation between biases, a one-factor model might be more appropriate to explain the scale's underlying construct. Biases were associated with a greater frequency of delusions, distress, conviction, and concern as well as worse cognitive insight in patients with psychosis.

Network analysis of psychotic manifestations among cocaine users

Psychotic experiences can be described along a continuum ranging from no psychotic experience at all, to clinical psychotic disorder. Any individual in the general population may encounter psychotic experiences under certain circumstances. Transient Cocaine Induced Psychotic Symptoms (TCIPS) are a well described model of such circumstances.Therefore, our aim was to use a network analysis to get a better knowledge on the architecture of previously described risk factors and how they contributed to two different measures of psychosis (psychosis proneness and transient cocaine induced psychotic symptoms)This study is a secondary analysis conducted among 180 cocaine users in addiction care centers in Paris and Paris suburb, who were evaluated with the PDI (Peters Delusion Inventory) and the SAPS-CIP (Scale for the Assessment of Psychotic Symptoms – Cocaine Induced Psychosis). Schizophrenia diagnosis was extracted from medical record. Relevant variables significantly associated with SAPS-CIP total score or PDI at the first step were included in a network analysis to better figurate their respective associations.The network centrality measures showed that the product preferentially used (crack vs cocaine) was related to TCIPS, psychosis proneness and, to a lesser extent, schizophrenia. Secondly, in this model TCIPS is a mediator between intensive cocaine use and psychosis proneness. Thirdly, this study refines the previous knowledge on heavy cannabis use being a risk factor for TCIPS. The observed link is not direct but mediated by psychosis proneness.

Jumping to conclusions in the less-delusion-prone? Further evidence from a more reliable beads task.

A single meta-analysis has found that healthy people with higher delusion-proneness tend to gather less information (i.e., make fewer draws to decision, or DTD) on the beads task, although the findings of contributing studies were mixed, and the pooled effect size was small. However, using a new and more reliable "distractor sequences" beads task, we recently found a positive relationship between delusion-proneness and DTD in a healthy sample. In the current study, we re-tested this relationship in a new sample, and tested the possibility that the relationship is driven by participant's ability to understand and use odds or likelihood information ("odds literacy"). Healthy participants (N=167) completed the distractor sequences beads task, the Peters Delusions Inventory (PDI) which measures delusion-proneness, a measure of odds literacy, and the Depression, Anxiety, and Stress scale. PDI and DTD were positively correlated, and comparing PDI quartiles on DTD confirmed a statistically significant trend of increasing DTD with PDI quartile. Odds literacy was positively rather than negatively associated with both DTD and PDI. Anxiety was positively correlated with PDI and DTD. We replicated our earlier finding that DTD and delusion-proneness were positively related in a non-clinical sample, but found that increased odds-literacy did not drive lower PDI and DTD, and hence did not explain their covariance. It is possible however that anxiety and co-occurring risk aversion drive increased delusion-proneness and information-gathering, potentially accounting for the positive relationship between PDI and DTD.

S80. CHILDHOOD TRAUMA AND SOCIAL COGNITION IN DELUSIONAL PSYCHOSES

BackgroundDeficits in social cognition could be involved in the pathogenesis of delusions in psychotic disorders (Bentall et al., 2009). Childhood trauma (CT) has been associated with an increased risk for psychosis (Varese et al., 2012). Neurocognitive and social cognition deficits could mediate in the association between CT and psychosis (Mansueto et al., 2019). Social cognition and childhood trauma have been understudied so far in delusional disorder (DD). We aimed to assess social cognition in a sample of patients with delusional psychoses (i.e., DD and schizophrenia) and healthy controls (HC) and to explore the potential effect of childhood trauma on social cognition and delusion.MethodsThis cross-sectional, transdiagnostic study included 69 patients with a DSM-IV-TR-confirmed diagnosis of DD (mean age 44.06 ± 11.39 years, 53.6% female), 77 with DSM-IV-TR-confirmed schizophrenia (mean age 38.12 ± 9.27 years, 27.3% female), and 63 HC (mean age 43.6 ± 13.0 years, 68.3% female). Attributional bias was assessed with the “Internal, Personal, and Situational Attributions Questionnaire.” Theory of Mind (ToM) performance was assessed with the “Reading the Mind in the Eyes Test” and the “Faux Pas Recognition Test.” Childhood trauma was measured with the “Childhood Trauma Questionnaire.” Neuropsychological functioning was measured with a comprehensive battery assessing attention, verbal learning, working memory, and executive function. We used ANCOVAs and linear regression analyses to assess the association between the three measures of social cognition and i) diagnosis, ii) dimensional measures of delusion proneness (Peters Delusion Inventory, PDI) and intensity (Maudsley Assessment of Delusion Schedule, MADS), and iii) childhood trauma; after controlling for potential confounders (age, sex, socioeconomic status, and estimated premorbid intelligence quotient).ResultsPatients with DD showed significantly poorer performance on the “Eyes Test” than HC (Cohen’s d=-0.44, p=0.037), after controlling for potential confounding variables. The difference was no longer significant after controlling for verbal memory. Patients with schizophrenia (d=-1.54, p<0.001) and DD (Cohen’s d=-0.60, p=0.002) showed significantly poorer performance than HC on the “Faux Pas Test,” after controlling for potential confounders. The difference between patients with schizophrenia and HC remained significant after controlling for neuropsychological functioning (Cohen’s d=-1.09, p<0.001), while differences between patients with DD and HC were no longer significant after controlling for executive function and working memory performance (Cohen’s d=-0.23, p=0.596). No significant differences were found between diagnostic groups in externalizing or personalizing attributional bias. In the fully adjusted models, intensity of the delusional idea was significantly associated with performance in the “Faux Pas Test” in DD, and with externalizing and personalizing attributional bias in schizophrenia. A positive history of CT was significantly associated with lower performance on the “Faux Pas Test” (Cohen’s d=-0.40, p=.022) and higher delusional proneness scores in the delusional psychosis samples (Cohen’s d=-0.49, p=.006), but not in HC.DiscussionSocial cognition deficits are associated with delusional intensity in delusional psychoses. Childhood trauma could increase the risk of psychosis through its effect on social cognition.

S75. PERFORMANCE IN WORKING MEMORY AND EXECUTIVE FUNCTIONS AS IT RELATES TO THEORY OF MIND ABILITIES IN A NONCLINICAL SAMPLE OF INDIVIDUALS WITH SCHIZOTYPAL TRAITS

BackgroundIn recent decades, research in the treatment of schizophrenia has shifted to early detection and intervention. Unfortunately, the development of psychosis is still poorly understood, making such an endeavour more challenging. Cognitive models of psychosis suggest that neurocognitive deficits place an individual at greater risk of developing metacognitive deficits. Such deficits in metacognition have been shown to contribute to the development of positive symptomatology. A large body of literature supports that patients with schizophrenia exhibit impairments across nearly all domains of neurocognition, as well as metacognition. Theory of mind (ToM) is one of the most widely studied components of metacognition, which includes both cognitive (i.e., understanding what another person is thinking) and affective (i.e., understanding what another person is feeling) processes. Research indicates patients with schizophrenia demonstrate deficits in cognitive and affective ToM, and these deficits are associated with delusional symptomatology. If ToM is involved in the development of positive symptoms, it is expected that this deficit would be present prior to the onset of a first episode psychosis. It is unclear from current research findings if this is the case, however. Additionally, research examining the role of neurocognition as it relates to ToM is lacking. While some research has examined these variables in clinically-high-risk (CHR) groups, little research has examined nonclinical samples at risk for psychosis. Thus, this study sought to examine the relationship between ToM and neurocognition in a nonclinical sample with schizotypal traits, as research suggests these individuals may be at risk of developing a psychotic illness. It was hypothesized that lower performance in working memory and executive functioning would be related to poorer performance in cognitive and affective ToM, which would subsequently be associated with subsyndromal delusions. It was further predicted that schizotypal traits would moderate the relationship between neurocognitive performance and ToM abilities.MethodsUndergraduate students (N = 99) completed self-report measures of personality and psychosocial functioning, including the Schizotypal Personality Questionnaire, Beck Depression Inventory-II, Launay-Slade Hallucination Scale-Revised, and 21-Item Peters Delusions Inventory. Participants also completed the Neuropsychological Assessment Battery Screening Module, which is a screening measure for neurocognitive dysfunction. Finally, they completed the Recognition of Faux Pas Test, a task-based measure that evaluates cognitive and affective ToM.ResultsData collection is complete, and the data will be analysed using partial least squares structural equation modeling. This is a regression-based path analysis designed for exploratory models. This statistical method is better able to handle non-normally distributed data and smaller sample sizes when compared to covariance-based structural equation modeling.DiscussionStudy findings will be discussed in the context of cognitive models for the development of psychosis. The ways in which these findings, and cognitive models more broadly, can facilitate early detection of schizophrenia will be discussed, along with how such models can be used to inform psychosocial interventions for the illness.

Jumping to conclusions in the less-delusion-prone? Preliminary evidence from a more reliable beads task

Background and objectivesSeveral meta-analyses have shown that people with psychosis tend to gather less information (i.e., they make fewer draws to decision, or DTD) on the beads task than healthy controls. A single meta-analysis has also found a small negative association between delusion-proneness and DTD in healthy samples, but with considerable heterogeneity. MethodsWe used the new and more reliable “distractor sequences” beads task to clarify the nature of the relationship between delusion-proneness and DTD in a healthy sample. Healthy participants (N = 203) completed the distractor sequences beads task and the Peters Delusions Inventory (PDI), which measures delusion-proneness. ResultsPDI and DTD were positively correlated, and those who jumped to conclusions (DTD ≤ 2) had lower PDI than those who did not. Comparing PDI quartiles on DTD provided some evidence the positive association did not extend to the highest PDI quartile. We found that DTD and delusion-proneness were positively related in our non-clinical sample, which was unexpected. LimitationsResults need replication with a clinical sample. ConclusionsConsidering the well-established association between the JTC bias and clinical delusions, the current finding may reflect a relationship that differs between non-clinical and clinically significant delusional groups, or one which reverses sign at some level of delusion-proneness.

Risky decision-making and delusion proneness: An initial examination

Delusion proneness is an individual-differences characteristic, existing on a continuum from no delusional thoughts to a diagnosis of schizophrenia. Previous research found individuals high in delusion proneness request less information to make decisions, potentially making a decision without sufficient information (jumping to conclusions). The present study examined risky decision-making as a function of delusion proneness. Participants (n = 102) completed the Peters Delusions Inventory to assess delusion proneness, and the Iowa Gambling Task (IGT) and Game of Dice Task (GDT) to assess risky decision-making. Although no significant results emerged on the GDT, those scoring higher in delusion proneness decided more advantageously on the IGT than those scoring lower in delusion proneness. Exploratory analyses indicated no significant relationship between gender and task performance. The present study provides further insight into risky decision making as a function of delusion proneness.

Does Change over Time in Delusional Beliefs as Measured with PDI Predict Change over Time in Belief Flexibility Measured with MADS?

Delusional beliefs and their behavioral consequences are predominant symptoms in patients with psychosis and play an important role in the treatment. Delusional beliefs are a multidimensional concept which can be divided into three components: distress, preoccupation and conviction of delusions. These can be measured using Peters delusions inventory (PDI-21). We question, whether changes in delusional beliefs over time during treatment measured with the PDI-21 can predict changes in belief flexibility measured with the Maudsley assessment of delusions schedule (MADS). We used a group of patients from a randomized controlled trial for a cognitive intervention for psychosis or psychotic symptoms. Aside standard treatment for psychosis, half of the patients took part in a group treatment "Michael's game". Patients were assessed at baseline (T1), at 3months (T2), and at 9months (T3). We measured delusional beliefs using PDI-21 and belief flexibility with the MADS. One hundred seventy-two patients were included in the analysis. We measured a main effect of PDI-21scores on belief flexibility measured with MADS. PDI-21 Conviction scores predicted outcomes for all measured MADS items. Increasing PDI Distress and Preoccupation scores were predictors for being more likely to dismiss beliefs and change conviction. Time itself was a predictor for changing conviction and being able to plan a behavioral experiment. Overall the changes in PDI scores predicted outcomes for belief flexibility measured with MADS items. The PDI-21 could be a simple and effective way to measure progress in treatment on delusional beliefs.

Cost Evaluation During Decision-Making in Patients at Early Stages of Psychosis.

Jumping to conclusions during probabilistic reasoning is a cognitive bias reliably observed in psychosis and linked to delusion formation. Although the reasons for this cognitive bias are unknown, one suggestion is that psychosis patients may view sampling information as more costly. However, previous computational modeling has provided evidence that patients with chronic schizophrenia jump to conclusions because of noisy decision-making. We developed a novel version of the classical beads task, systematically manipulating the cost of information gathering in four blocks. For 31 individuals with early symptoms of psychosis and 31 healthy volunteers, we examined the numbers of “draws to decision” when information sampling had no, a fixed, or an escalating cost. Computational modeling involved estimating a cost of information sampling parameter and a cognitive noise parameter. Overall, patients sampled less information than controls. However, group differences in numbers of draws became less prominent at higher cost trials, where less information was sampled. The attenuation of group difference was not due to floor effects, as in the most costly block, participants sampled more information than an ideal Bayesian agent. Computational modeling showed that, in the condition with no objective cost to information sampling, patients attributed higher costs to information sampling than controls did, Mann–Whitney U = 289, p = 0.007, with marginal evidence of differences in noise parameter estimates, t(60) = 1.86, p = 0.07. In patients, individual differences in severity of psychotic symptoms were statistically significantly associated with higher cost of information sampling, ρ = 0.6, p = 0.001, but not with more cognitive noise, ρ = 0.27, p = 0.14; in controls, cognitive noise predicted aspects of schizotypy (preoccupation and distress associated with delusion-like ideation on the Peters Delusion Inventory). Using a psychological manipulation and computational modeling, we provide evidence that early-psychosis patients jump to conclusions because of attributing higher costs to sampling information, not because of being primarily noisy decision makers.

RELATIONSHIP OF MODELS OF CONSISTENCY AND PSYCHOLOGICAL FLEXIBILITY WITH PERSECUTORY DELUSIONS

The goal of research is to assess the preference for consistency, cognitive fusion and experiential avoidance levels and their of persons with delusional persecution delusions, and interrelationship of these items. In addition, it was aimed to investigate the attitudes of individuals with persecution delusions towards the inconsistency of the relationship with other cognitions and their discomfort caused by inconsistency. The patient group with delusions consisted of 82 patients was who were diagnosed with schizophrenia, schizophreniform, schizoaffective disorder, delusional disorder, unspecified psychotic For the control group, 86 people who showed similar characteristics were included in the study Participants in both groups fill form for the Sociodemographic Data Form, Preference for Consistency Scale (PFC), Peters Delusion Inventory (PDI, only items for Persecutory Delusion), Cognitive Fusion Scale (CFQ), acceptance and Action questionnaire-II (AAQ-II) themselves. In addition, the Positive and Negative Syndrome Scale (PANSS, only positive symptom subscale) was applied by the researcher in the patient group with delusions. There was a significant difference between the patient group with delusions and the control group for the scores of PFC, AAQ-II and CFQ (p