The contributions of risk-taking and impulsivity to jumping to conclusions in the psychosis spectrum.

The jumping to conclusions (JTC) bias has been linked to the formation and maintenance of delusions across the psychosis spectrum. However, it remains unclear whether this bias reflects a primary cognitive deviation or is secondary to other cognitive processes. To this end, we investigated the relationship between JTC, risk-taking, impulsivity, and sensation seeking in individuals with psychotic-like experiences (PLEs) and controls. A large online community sample (N = 1151) completed the Fish Task as a measure for the JTC bias, as well as the Balloon Analogue Risk Task (BART) and the Brief Risk-Taking Propensity Scale (R-1) as measures of the propensity to take risks. Measures assessing impulsivity (Impulsive Behavior Scale-8, I-8), sensation seeking (Brief Sensation Seeking Scale, BSSS-4), and verbal intelligence (12-item Wordsum test) were also administered. We dichotomized the sample into extreme groups based on the positive subscale of the Community Assessment of Psychotic Experiences (CAPE). The present study confirms the existence of a JTC bias in psychosis-prone individuals. Of note, PLE-high individuals self-reported higher risk-taking propensity in the R-1 while at the same time displaying higher objective risk aversion in the BART relative to controls, speaking for a dissociation of subjective versus objective risk-taking behavior. PLE-high individuals showed deviances in other psychological traits (impulsivity, sensation seeking), but these were not associated with hasty decision-making as measured by JTC or risk-taking propensity. The results speak against impulsivity, sensation seeking, or verbal intelligence as driving mechanisms of JTC and risky decision-making.

Hasty decision making and belief inflexibility in the more delusion prone? A modified disambiguating-scenarios paradigm assessing cognitive biases implicated in delusions.

INTRODUCTION: Contemporary models of psychosis imply that cognitive biases such as the jumping to conclusions (JTC), the bias against disconfirmatory evidence (BADE), and the liberal acceptance (LA) bias play a role in the pathogenesis of delusions. Most of the studies investigating the role of cognitive biases, however, have been conducted with socially neutral or abstract stimuli and have assessed patients with established psychoses. For the present study, we aimed to concurrently investigate multiple biases (i.e., the JTC, BADE, and LA biases) in a community sample with a new paradigm using more socially engaging stimuli. METHODS: A large sample of participants (N = 874) recruited via Amazon Mechanical Turk was subdivided into two groups based on the frequency of their psychotic-like experiences (PLEs) according to the positive subscale score of the Community Assessment of Psychic Experiences (CAPE) and matched based on major demographics variables, resulting in two equally sized groups called High-PLE (at least 2 SD above the mean) and Low-PLE (maximum 0.5 above the mean; n = 46 for each group). Using a modified version of the written-scenarios BADE task, which emphasized social interactions between agents embedded in the scenario, participants rated the plausibility of response options in the face of new information. RESULTS: In line with previous findings, the High-PLE group demonstrated the JTC, BADE, and LA biases. That is, the members of this group made more decisions after the initial piece of information, were less likely to revise their beliefs in light of new information, and provided higher plausibility ratings for implausible response options compared to the Low-PLE group. CONCLUSIONS: Results corroborate prior findings suggesting that the JTC, BADE, and LA biases may be contributing factors in delusional ideation and that metacognitive biases extend to social situations.

A randomized controlled feasibility trial of metacognitive training with adolescents receiving treatment for anorexia nervosa.

OBJECTIVE: This pilot study investigated the feasibility and preliminary efficacy of the metacognitive training for eating disorders (MCT-ED) program in adolescents with anorexia nervosa (AN). We report attrition and subjective evaluation as well as changes to cognitive flexibility, perfectionism and eating disorder pathology relative to waitlist controls. METHOD: Female (n = 35, aged 13-17 years) outpatients with a diagnosis of AN (n = 20) or atypical AN (n = 15) completed baseline measures of cognitive flexibility, perfectionism, and eating disorder pathology (May 2020-May 2022). Participants were randomly allocated to either treatment-as-usual (TAU) plus MCT-ED or TAU waitlist condition. All participants completed post-intervention and 3-month follow-up questionnaires. RESULTS: The MCT-ED condition had a treatment attrition rate <15%. Participants provided positive evaluation of the program. There were large between groups differences favoring MCT-ED at post-intervention and 3-month follow-up for concern over mistakes perfectionism (respective ds = -1.25, 95% CI [-2.06, -.45]; -.83, 95% CI [-1.60, .06]) with a significant group difference post-intervention but not 3-month follow-up. DISCUSSION: Findings provide tentative support for the feasibility of MCT-ED as an adjunct intervention for young people with AN, however replication is needed with a larger sample size to further explore its efficacy. PUBLIC SIGNIFICANCE: Metacognitive training for eating disorders (MCT-ED) is a feasible adjunct intervention for adolescents with anorexia nervosa. The intervention, which targets thinking styles and is delivered online by a therapist, received positive feedback, had high treatment retention, and led to reductions in perfectionism by the end of treatment compared to wait-list controls. Although these gains were not sustained long-term, the program is suitable adjunct intervention for young people with eating disorders.

Hasty decision-making in individuals at higher risk of developing an eating disorder.

BACKGROUND AND OBJECTIVES: The Jumping to Conclusions (JTC) bias is the tendency to make hasty decisions based on limited evidence and may contribute to the formation of over-valued beliefs about the importance of weight, shape and eating. Previous research investigating the JTC bias in clinical eating disorder samples, as assessed by the beads task, is inconclusive. The current study investigated the JTC bias in a non-clinical sample of undergraduate students identified as being lower or higher risk of developing an eating disorder. The study used a more reliable 'distractor' beads task that also incentivised hastier decisions by elevating the pressure of the task. METHODS: Female undergraduate students (N = 156, 48%, classified as higher risk) completed a pressure and non-pressure distractor beads task, along with measures of weight concern and body-image flexibility. RESULTS: Higher risk participants displayed a hastier decision-making style than lower risk participants. Task pressure elicited a hastier decision-making style across the whole sample, however, was unable to distinguish between higher and lower eating disorder risk status. LIMITATIONS: Interpretation of findings are limited to non-clinical samples and may not generalise to clinical eating disorder populations. CONCLUSIONS: Findings suggest the need for replication in a clinical eating disorder sample using the distractor beads task. Future research should investigate whether eating disorder salient stimuli elicits a stronger bias.

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

BACKGROUND: 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"). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Prolonged rather than hasty decision-making in schizophrenia using the box task. Must we rethink the jumping to conclusions account of paranoia?

Jumping to conclusions (JTC) is the best established cognitive bias in schizophrenia and is increasingly targeted in interventions aimed to improve positive symptoms. To address shortcomings of the standard measure to capture JTC, the beads task, we developed a new variant-the box task-which was subsequently validated in people with elevated psychotic-like experiences. For the first time, the box task was administered in a sample of individuals with manifest schizophrenia. We hypothesized that patients with schizophrenia would display an elevated JTC bias relative to controls. METHOD: We recruited a large sample of 101 patients with schizophrenia and matched them to an online sample recruited from the general population. In the box task, participants must decide which of two kinds of colored balls are presented more often. Participants are told that the task may end prematurely, and that task performance will be counted as an error if no decision had been made before that point. The primary measure was the number of draws to decision (DTD), where fewer DTD corresponds to greater JTC. RESULTS: In contrast to expectations, participants with schizophrenia showed significantly higher DTD (i.e., reduced JTC). Consistent with our previous findings, patients also displayed a lowered decision threshold compared to controls. Response confidence for the final decision was lower in patients and correlated with self-esteem and positive symptoms. While there was evidence that previous knowledge of the box task lowered DTD, exclusion of participants with experience on the box task did not substantially change results. DISCUSSION: The study fits a growing body of experiments casting doubt on the generalizability of the JTC effect in schizophrenia across different tasks. While the study tentatively supports a liberal acceptance account of psychosis, caution is warranted and we recommend that research should explore and control for potentially important mediators (e.g., task difficulty, stress, test-taking attitudes).

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

BACKGROUND AND OBJECTIVES: Several 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. METHODS: We 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. RESULTS: PDI 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. LIMITATIONS: Results need replication with a clinical sample. CONCLUSIONS: Considering 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.

Individualized Metacognitive Training (MCT+) Reduces Delusional Symptoms in Psychosis: A Randomized Clinical Trial.

Individualized metacognitive training (MCT+) is a novel psychotherapy that has been designed to specifically target delusional beliefs in people with psychosis. It works by developing an awareness of the implausible content of delusional beliefs, while also targeting the cognitive biases that contribute to their formation and maintenance. It was expected that MCT+ would lead to significantly greater reductions in delusional severity compared to a cognitive remediation (CR) active control condition. A total of 54 patients with a schizophrenia spectrum disorder and active delusions were randomized into four 2-hourly sessions of MCT+ (n = 27) or CR (n = 27). All participants completed posttreatment assessment, and only 2 participants did not complete 6-month follow-up assessment, resulting in MCT+ (n = 26) and CR (n = 26) for final analysis. The primary outcome measures of delusional and positive symptom severity were assessed rater-blind; secondary outcome assessment was non-blinded and included clinical and cognitive insight, the jumping to conclusions (JTC) bias, and cognitive functioning. Participants in the MCT+ condition showed significant reductions in delusional and overall positive symptom severity (large effect) and improved clinical insight (moderate effect) relative to CR controls. In contrast, CR controls showed moderate improvement in problem-solving ability relative to MCT+, but no other cognitive domain. Importantly, these findings were maintained at 6-month follow-up. The study adds further efficacy to the MCT program, and suggests that even brief psychotherapy can help to ameliorate the symptoms of psychosis.

Towards a reliable repeated-measures beads task for assessing the jumping to conclusions bias.

The jumping to conclusions bias (JTC), in which some people gather less information than others before making a decision, has been linked to delusions in psychosis. JTC is usually identified via the beads task, in which a sequence of beads (the "target" sequence) is used to measure the amount of evidence participants require before making a decision. Yet, despite its common use, the reliability of the task has never been properly investigated. We investigated its reliability, and tested an alternate version which used distractor sequences to obfuscate the target sequence. Healthy participants (N = 212) were randomised into two groups. One group completed ten trials using the target sequence, while the other completed ten trials of the target sequence and three distractor sequences. Our data indicated the standard task may not be reliable over repeated measures, but that by including distractor sequences, the task becomes more believable, repeatable, and reliable. Additionally, excluding first-trial data (a "silent" practice trial) also improves repeatability. These improvements to the task are relevant to single trial studies, and will be especially useful to repeated-measures longitudinal, experimental, and treatment studies. Such repeated-measures studies are important for investigating the causal link between JTC and delusions.

Dopamine, cognitive biases and assessment of certainty: A neurocognitive model of delusions.

This paper examines the evidence that delusions can be explained within the framework of a neurocognitive model of how the brain assesses certainty. Here, 'certainty' refers to both low-level interpretations of one's environment and high-level (conscious) appraisals of one's beliefs and experiences. A model is proposed explaining how the brain systems responsible for assigning certainty might dysfunction, contributing to the cause and maintenance of delusional beliefs. It is suggested that delusions arise through a combination of perturbed striatal dopamine and aberrant salience as well as cognitive biases such as the tendency to jump to conclusions (JTC) and hypersalience of evidence-hypothesis matches. The role of emotion, stress, trauma and sociocultural factors in forming and modifying delusions is also considered. Understanding the mechanisms involved in forming and maintaining delusions has important clinical implications, as interventions that improve cognitive flexibility (e.g. cognitive remediation therapy and mindfulness training) could potentially attenuate neurocognitive processes.

Shorter telomere length in people with schizophrenia: A preliminary study from Australia.

Schizophrenia is a complex mental illness affecting the normal functioning of the brain, interfering with the ability to think, feel and act. It can be conceptualised as a syndrome of accelerated ageing, with early onset of cardiovascular disease and high rates of premature mortality. Telomere attrition increases with oxidative stress and is considered a biomarker of ageing. Previous studies have assessed abnormalities in telomere length in schizophrenia, but the results are inconsistent. The present study used a case-control design to assess whether people with schizophrenia have shortened telomeres, indicative of accelerated ageing. Subjects were all male, aged 25-35years, living in the same urban region of Adelaide, South Australia. Telomere length was measured using a quantitative real-time polymerase chain reaction (PCR) method. We found significantly shorter telomeres in people with schizophrenia relative to healthy controls. This is the first study to show telomere attrition among people with schizophrenia in Australia. Shorter telomere length may indicate the common pathways that schizophrenia shares with other neuropsychiatric and neurodevelopmental disorders associated with increased cellular senescence. Further well-controlled larger studies in people with schizophrenia are required to fully understand (i) the role of variables that have the potential to modulate telomere length such as use of antipsychotic drugs, medical conditions, parental age, smoking, alcohol abuse and use of illicit drugs; (ii) effective treatments to slow telomere erosion and (iii) mechanisms responsible for accelerating and reducing telomere damage.

A new paradigm to measure probabilistic reasoning and a possible answer to the question why psychosis-prone individuals jump to conclusions.

Jumping to conclusions (JTC) distinguishes patients with schizophrenia from both healthy and psychiatric controls. JTC is typically assessed using the beads task, which, however, faces a number of limitations as to its interpretability and reliability. The present study set out to validate a new paradigm to assess JTC: the box task. We adopted a psychometric psychosis proneness approach and divided a large population sample into participants who scored high versus low on a scale tapping psychosis-like experiences. Participants performed a variant of the original beads task along with a new JTC task, the box task, with or without time pressure. The box task requires participants to infer which of two ball colors will be more prevalent in a matrix of boxes. The box task and the beads task were significantly correlated at a medium effect size, thus demonstrating criterion validity for the box task. As hypothesized, participants who scored high on psychosis-like experiences showed particularly strong JTC and a decreased decision threshold relative to low scorers, especially in the box task version with time pressure; in contrast, group differences in the beads tasks only achieved trend-wise significance. Mediation analyses showed that fewer draws to decisions were predicted by either a lower decision threshold or by higher initial probability estimates for the dominant item. The study establishes the criterion and construct validity of a new JTC task. Its advantages over the traditional beads task are better comprehensibility and usability; multiple parallel versions can be created thus raising reliability. (PsycINFO Database Record

Association of the Jumping to Conclusions and Evidence Integration Biases With Delusions in Psychosis: A Detailed Meta-analysis.

We completed a meta-analysis to investigate the relationship between delusions in psychosis and 4 cognitive biases: "jumping to conclusions" (JTC), the "bias against disconfirmatory evidence" (BADE), the "bias against confirmatory evidence" (BACE), and "liberal acceptance" (LA). Building on recent meta-analyses we compared more narrowly defined groups. We identified 35 JTC, 8 BADE, 7 BACE, and 6 LA studies for inclusion. Groups with schizophrenia who were currently experiencing delusions demonstrated greater JTC, BADE, BACE, and LA than groups with schizophrenia who were not currently experiencing delusions, who in turn demonstrated no more JTC than healthy control groups. Hence JTC, BADE, BACE, and LA co-vary with delusions in cross-sectional samples of people with schizophrenia. Groups who were experiencing delusions due to other psychiatric illnesses also demonstrated greater JTC than healthy controls, and equivalent JTC to groups with schizophrenia currently experiencing delusions. Hence JTC is associated with delusions across a range of diagnoses. Groups with other, non-delusional psychiatric illnesses demonstrated less JTC, BADE, BACE, and LA than groups with schizophrenia currently experiencing delusions, less JTC than groups experiencing delusions due to other diagnoses, and no more JTC, BADE, BACE, or LA than healthy control groups. Hence JTC, BADE, BACE, and LA were not associated with psychiatric illnesses in general. Our results indicate all 4 biases are associated with delusions specifically rather than merely with a diagnosis of schizophrenia or with being psychiatrically ill, consistent with the possibility that they contribute to delusional severity.

A two-stage cognitive theory of the positive symptoms of psychosis. Highlighting the role of lowered decision thresholds.

OBJECTIVES: We outline a two-stage heuristic account for the pathogenesis of the positive symptoms of psychosis. METHODS: A narrative review on the empirical evidence of the liberal acceptance (LA) account of positive symptoms is presented. HYPOTHESIS: At the heart of our theory is the idea that psychosis is characterized by a lowered decision threshold, which results in the premature acceptance of hypotheses that a nonpsychotic individual would reject. Once the hypothesis is judged as valid, counterevidence is not sought anymore due to a bias against disconfirmatory evidence as well as confirmation biases, consolidating the false hypothesis. As a result of LA, confidence in errors is enhanced relative to controls. Subjective probabilities are initially low for hypotheses in individuals with delusions, and delusional ideas at stage 1 (belief formation) are often fragile. In the course of the second stage (belief maintenance), fleeting delusional ideas evolve into fixed false beliefs, particularly if the delusional idea is congruent with the emotional state and provides "meaning". LA may also contribute to hallucinations through a misattribution of (partially) normal sensory phenomena. Interventions such as metacognitive training that aim to "plant the seeds of doubt" decrease positive symptoms by encouraging individuals to seek more information and to attenuate confidence. The effect of antipsychotic medication is explained by its doubt-inducing properties. LIMITATIONS: The model needs to be confirmed by longitudinal designs that allow an examination of causal relationships. Evidence is currently weak for hallucinations. CONCLUSIONS: The theory may account for positive symptoms in a subgroup of patients. Future directions are outlined.

Beads task vs. box task: The specificity of the jumping to conclusions bias.

BACKGROUND AND OBJECTIVES: Previous research involving the probabilistic reasoning 'beads task' has consistently demonstrated a jumping-to-conclusions (JTC) bias, where individuals with delusions make decisions based on limited evidence. However, recent studies have suggested that miscomprehension may be confounding the beads task. The current study aimed to test the conventional beads task against a conceptually simpler probabilistic reasoning "box task" METHODS: One hundred non-clinical participants completed both the beads task and the box task, and the Peters et al. Delusions Inventory (PDI) to assess for delusion-proneness. The number of 'draws to decision' was assessed for both tasks. Additionally, the total amount of on-screen evidence was manipulated for the box task, and two new box task measures were assessed (i.e., 'proportion of evidence requested' and 'deviation from optimal solution'). RESULTS: Despite being conceptually similar, the two tasks did not correlate, and participants requested significantly less information on the beads task relative to the box task. High-delusion-prone participants did not demonstrate hastier decisions on either task; in fact, for box task, this group was observed to be significantly more conservative than low-delusion-prone group. LIMITATIONS: Neither task was incentivized; results need replication with a clinical sample. CONCLUSION: Participants, and particularly those identified as high-delusion-prone, displayed a more conservative style of responding on the novel box task, relative to the beads task. The two tasks, whilst conceptually similar, appear to be tapping different cognitive processes. The implications of these results are discussed in relation to the JTC bias and the theoretical mechanisms thought to underlie it.