Explaining delusions: a cognitive perspective

Delusions and Delinquencies: A Comparison of Violent and Non-Violent Offenders With Schizophrenia Spectrum Disorders

The relationship between schizophrenia spectrum disorders (SSD) and violent offending has long been the subject of research. The present study attempts to identify the content of delusions, an understudied factor in this regard, that differentiates between violent and non-violent offenses. Limitations, clinical relevance, and future directions are discussed. Employing a retrospective study design, machine learning algorithms and a comprehensive set of variables were applied to a sample of 366 offenders with a schizophrenia spectrum disorder in a Swiss forensic psychiatry department. Taking into account the different contents and affects associated with delusions, eight variables were identified as having an impact on discriminating between violent and non-violent offenses with an AUC of 0.68, a sensitivity of 30.8%, and a specificity of 91.9%, suggesting that the variables found are useful for discriminating between violent and non-violent offenses. Delusions of grandiosity, delusional police and/or army pursuit, delusional perceived physical and/or mental injury, and delusions of control or passivity were more predictive of non-violent offenses, while delusions with aggressive content or delusions associated with the emotions of anger, distress, or agitation were more frequently associated with violent offenses. Our findings extend and confirm current research on the content of delusions in patients with SSD. In particular, we found that the symptoms of threat/control override (TCO) do not directly lead to violent behavior but are mediated by other variables such as anger. Notably, delusions traditionally seen as symptoms of TCO, appear to have a protective value against violent behavior. These findings will hopefully help to reduce the stigma commonly and erroneously associated with mental illness, while supporting the development of effective therapeutic approaches.

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.

The impact of bias on developing healthy lifestyles, understanding if personal perspectives impact modeling and recommendations of diet and exercise by educators to their students

Purpose

Educators have an ability to imprint healthy behavior in children. Yet, little is known about how a bias by educators might impact imprinting on students. Therefore, we examined if educators' bias in opinions about diet and exercise influence the manner they are discussed with students.

Methods

340 (144 F/196 M) educators from over 14 states (USA) provided responses regarding: personal opinions about and history of following diets or using exercise regimens; perspective on commonly held beliefs regarding diet, exercise, body image and morphology; and who should provide recommendations. Responses were tabulated for average and percentage with subsequent analysis by Pearson correlations or keyword frequencies of responses.

Results

Almost all (97%) understand social pressures related to body image and need to portray healthy behaviors to students. Bias was evident based on history of recommending or discouraging a specific diet (r = 0.77) or a dietary supplement (r = 0.66), recommending exercise they used (r = 0.89) or discouraging ones not used (r = 0.65). Most (85%) understand that social and mass media are not reliable sources, yet, relied on the same sources for information that reinforced their opinions.

Conclusion

Findings indicate (1) portrayal of healthy behaviors to students exist but expressed opinion that families have a greater influence than educators on healthy lifestyles, (2) there appears to be an unawareness of personal bias or expression of implicit bias toward behaviors projected to students, and (3) health/physical education and life science teachers may be able to act as a source of unbiased information to provide resources to a school site to aid in developing healthy lifestyles.

"The more things change…"? Stability of delusional themes across 12 years of presentations to an early intervention service for psychosis

PURPOSE

While the prevalence of delusional themes appears to be consistent across geographic contexts, little is known about the relative prevalence of such themes within a given setting over periods of time. We therefore investigated delusional themes across 12 years of presentation to a catchment-based early intervention service for first episode psychosis (FEP).

METHODS

Systematically collected data from 500 patients at an early intervention service for FEP were analyzed. Four cohorts of 3 years each, from 2006 to 2017, were used to compare the frequency of delusion themes across cohorts. We also integrated into the analysis baseline sociodemographic factors such as gender, age, and highest level of education and clinical factors such as anxiety, depression, suicidality, hallucinations, and primary diagnosis (affective or non-affective psychosis).

RESULTS

Sex and education level were stable across cohorts, while patient age varied (p = 0.047). Clinical anxiety, depression, and suicidality at entry were also stable. Across cohorts, the proportion of patients with affective versus non-affective diagnosis differed (p = 0.050), with no differences in global rating of delusion severity or theme prevalence except for delusions of guilt or sin (p = 0.001). This single theme difference was not correlated with age or diagnosis.

CONCLUSION

Our study suggests relatively stable prevalence of delusion themes across cohorts of individuals experiencing FEP. This demonstrates the potential utility of studying thematic content both for understanding delusions in clinical populations and in research. Future explorations of the relationships between delusion themes and across individual patient episodes should be conducted.

Efficacy of Metacognitive Training in a Chilean Sample of People with Schizophrenia

INTRODUCTION

Moritz et al.'s metacognitive training (MCT), a new development of cognitive therapy, is a manualised group training programme, designed to correct cognitive biases involved in the formation and maintenance of psychotic symptoms, especially delusions. We report on the efficacy of MCT in a Chilean sample of people with schizophrenia.

METHODS

50 outpatients from the Hospital Del Salvador in Valparaíso, Chile, were randomly assigned to the intervention group that received MCT or the control group that only received treatment as usual (TAU). Subjects were assessed at the beginning and end of the study with the Positive and Negative Syndrome Scale (PANSS), Cognitive Biases Questionnaire for Psychosis (CBQ-P) and Beck Cognitive Insight Scale (BCIS).

RESULTS

Greater statistically significant improvements were recorded in the MCT group, both in symptoms and cognitive biases and in cognitive insight, than in the control group. When comparing both groups, significant results in favor of MCT were only observed in positive symptoms.

CONCLUSIONS

The results of this study suggest MCT is superior to TAU in treating positive symptoms. It was not possible to demonstrate its superiority in improving cognitive biases and cognitive insight.

Remote group therapies for cognitive health in schizophrenia-spectrum disorders: Feasible, acceptable, engaging

Severe cognitive impairments and cognitive distortions are core to schizophrenia-spectrum disorders (SSDs) and are associated with deteriorated social functioning. Despite well-established efficacy of group psychosocial therapies targeting cognitive health in SSDs, dissemination of these programs remains limited. Remote delivery offers a promising strategy for increasing the programs' accessibility. Yet, little research has evaluated group therapies for cognitive health delivered in this way. Thus, we aimed to assess, from participants' and therapists' perspectives, the feasibility, acceptability, as well as levels and process of engagement in a videoconference delivery of group psychosocial therapies for SSD patients' cognitive health. Participants, outpatients, attended Action Based Cognitive Remediation or Metacognitive Training, both adapted for videoconference. Then, participants and therapists completed post-therapy questionnaires. Of the 28 participants attending at least one session, 75% completed more than half of sessions and seven dropped out. Technology did not appear to significantly hinder participation in the programs. All completing participants reported a positive experience with therapy, 67% were not bothered by the distance from the therapist, and 77% trusted that the information shared was kept confidential. Therapist-rated levels of attention M = 7.5/9 (SD = 1.04), participation M = 6.91/9 (SD = 1.32), and social interactions M = 5.31/9 (SD = 1.96) were satisfactory. Nonetheless, participants indicated that they would have appreciated more social interactions with group members. These positive results validate the earliest stage in the implementation process for remote group therapies targeting cognitive health in SSDs. Remote delivery promises to improve access to therapies targeting cognitive health and, ultimately, facilitate functional recovery for SSD patients.

Dependence Graphs Based on Association Rules to Explore Delusional Experiences

Methods to estimate dependence graphs among variables, have quickly gained popularity in psychopathology research. To date, multiple methods have been proposed but recent studies report several drawbacks impacting on the validity of the conclusions as it is argued that assumptions and conditions underlying the methods commonly used and the nature of the data is lacking alignment. A particularly important issue is that underlying dynamics potentially present in heterogeneous datasets are disregarded, as the methods focus on the variables but not on individuals. This work also argues that the networks may lack relevant components as current methods ignore connections beyond pairwise interactions between individual symptoms. This study addresses these issues with a novel method for constructing dependence graphs based on applying Association Rules to binary records, which is often the type of records in the psychopathology domain. To demonstrate the benefits, we examine 12 delusional experiences in a sample of 1423 subjects with psychotic disorders. We show that by extracting Association Rules using an algorithm called apriori, in addition to facilitating an intuitive interpretation, previously unseen relevant dependencies are revealed from higher order interactions among psychotic experiences in subgroups of patients.

People with schizophrenia use less information to interpret ambiguous social situations

BACKGROUND AND OBJECTIVES

The tendency of people with schizophrenia to gather insufficient information before making decisions or jumping to conclusions has been repeatedly reported. However, criticism has also been expressed regarding the ecological validity of this finding. Here we present the results obtained by a group of people with schizophrenia and a control group in a non-probabilistic task that requires obtaining items of information before interpreting an ambiguous social situation.

METHODS

Patients with schizophrenia (n = 48) and controls (n = 44) aged 18-50 years participated in the study. All subjects completed the Beads Task and the modified Social Information Preference Task.

RESULTS

Patients with schizophrenia showed a statistically significant tendency to jump to conclusions, including in the proposed novel social task. Unlike other studies, we were unable to find a relationship between this bias and greater severity of psychotic symptoms.

LIMITATIONS

We did not include patients with high levels of psychotic symptoms or a clinical control group.

CONCLUSIONS

The tendency to jump to conclusions in schizophrenia could be present in everyday interpersonal situations.

The profile of unusual beliefs associated with metacognitive thinking and attributional styles

Cognitive interpretations of daily events may differ in people from the general population who hold unusual beliefs. It is also important to understand whether different belief profiles exist to appreciate which patterns of beliefs are less psychologically healthy. Cluster analysis was used to form unusual belief profiles in a general population sample (n = 578; M_age = 22 years, SD = 6.98; 80% female) across paranoid, paranormal, and magical ideation beliefs, and we assessed whether they differed in attribution style and metacognitive beliefs about worry. Four clusters were formed: low on all measures (low all); high on all measures (high all); comparably higher on paranormal beliefs (paranormal group); and comparably higher on paranoid beliefs (paranoid group). For total Metacognitions Questionnaire‐30, the high all and high paranoid clusters did not differ, and both clusters scored higher than the high paranormal group, who all scored higher than the low all cluster. For attributional styles (Attributional Styles Questionnaire), lower scores on internal positive attribution were found for the high all and high paranoid clusters compared to the low all and high paranormal clusters. The high paranormal cluster had higher scores than the high paranoid cluster on self‐serving bias. Differences in attributional style appeared to be driven by mental health diagnosis. Our results suggest different profiles of unusual beliefs are detectable in the general population that differ in their metacognitive beliefs and perceived causation of events in their environment. Future studies investigating delusional proneness need to consider multiple unusual beliefs as well as assessing mood state and distress.

Efficacy of Metacognitive Training in a Chilean Sample of People with Schizophrenia

INTRODUCTION

Moritz et al.'s metacognitive training (MCT), a new development of cognitive therapy, is a manualized group training program, designed to correct cognitive biases involved in the formation and maintenance of psychotic symptoms, especially delusions. We report on the efficacy of MCT in a Chilean sample of people with schizophrenia.

METHODS

50 outpatients from the Hospital Del Salvador at Valparaíso, Chile, were randomly assigned to the intervention group (MCT), or the control group, that only received treatment as usual (TAU). Subjects were assessed at the beginning and end of the study with the Positive and Negative Syndrome Scale (PANSS), Cognitive Biases Questionnaire for Psychosis (CBQ-P) and Beck Cognitive Insight Scale (BCIS).

RESULTS

In the MCT group, we found larger, statistically significant improvements, in symptoms, cognitive biases and cognitive insight, than in the control group. However, after a direct comparison of both groups, only the improvement in psychotic symptoms for the MCT group, remained significantly different.

CONCLUSIONS

The results of this study suggest superiority of MCT over TAU in the amelioration of positive symptoms. We could not, however demonstrate its superiority in the improvement of the cognitive biases and cognitive insight.

Delusions beyond beliefs: a critical overview of diagnostic, aetiological, and therapeutic schizophrenia research from a clinical-phenomenological perspective

Delusions are commonly conceived as false beliefs that are held with certainty and which cannot be corrected. This conception of delusion has been influential throughout the history of psychiatry and continues to inform how delusions are approached in clinical practice and in contemporary schizophrenia research. It is reflected in the full psychosis continuum model, guides psychological and neurocognitive accounts of the formation and maintenance of delusions, and it substantially determines how delusions are approached in cognitive-behavioural treatment. In this Review, we draw on a clinical-phenomenological framework to offer an alternative account of delusion that incorporates the experiential dimension of delusion, emphasising how specific alterations to self-consciousness and reality experience underlie delusions that are considered characteristic of schizophrenia. Against that backdrop, we critically reconsider the current research areas, highlighting empirical and conceptual issues in contemporary delusion research, which appear to largely derive from an insufficient consideration of the experiential dimension of delusions. Finally, we suggest how the alternative phenomenological approach towards delusion could offer new ways to advance current research and clinical practice.

The tendency to stop collecting information is linked to illusions of causality

Previous research proposed that cognitive biases contribute to produce and maintain the symptoms exhibited by deluded patients. Specifically, the tendency to jump to conclusions (i.e., to stop collecting evidence soon before making a decision) has been claimed to contribute to delusion formation. Additionally, deluded patients show an abnormal understanding of cause-effect relationships, often leading to causal illusions (i.e., the belief that two events are causally connected, when they are not). Both types of bias appear in psychotic disorders, but also in healthy individuals. In two studies, we test the hypothesis that the two biases (jumping to conclusions and causal illusions) appear in the general population and correlate with each other. The rationale is based on current theories of associative learning that explain causal illusions as the result of a learning bias that tends to wear off as additional information is incorporated. We propose that participants with higher tendency to jump to conclusions will stop collecting information sooner in a causal learning study than those participants with lower tendency to jump to conclusions, which means that the former will not reach the learning asymptote, leading to biased judgments. The studies provide evidence in favour that the two biases are correlated but suggest that the proposed mechanism is not responsible for this association.

Clinical Lycanthropy, Neurobiology, Culture: A Systematic Review

Background: Culture can affect psychiatric disorders. Clinical Lycanthropy is a rare syndrome, described since Antiquity, within which the patient has the delusional belief of turning into a wolf. Little is known on its clinical or therapeutic correlates. Methods: We conducted a systematic review (PRISMA) on PubMed and Google Scholar, until January 2021. Case reports, data on neurobiological hypotheses, and cultural aspects were included. Language was not restricted to English. Results: Forty-three cases of clinical lycanthropy and kynanthropy (delusion of dog transformation) were identified. Associated diagnoses were: schizophrenia, psychotic depression, bipolar disorder, and other psychotic disorders. Antipsychotic medication may be an efficient treatment for this rare transnosographic syndrome. In case of depression or mania, the treatment included antidepressants or mood regulators. The neuroscientific hypotheses include the conception of clinical lycanthropy as a cenesthopathy, as a delusional misidentification of the self-syndrome, as impairments of sensory integration, as impairments of the belief evaluation system, and right hemisphere anomalies. Interestingly, there is a clinical overlap between clinical lycanthropy and other delusional misidentification syndromes. Clinical lycanthropy may be a culture-bound syndrome that happens in the context of Western cultures, myths, and stories on werewolves, and today's exposure to these narratives on cultural media such as the internet and the series. We suggest the necessity of a cultural approach for these patients' clinical assessment, and a narrative and patient-centered care. Conclusions: Psychiatric transtheoretical reflections are needed for complementaristic neurobiological and cultural approaches of complex delusional syndromes such as clinical lycanthropy. Future research should include integrative frameworks.

Derationalizing Delusions

Because of the traditional conceptualization of delusion as “irrational belief,” cognitive models of delusions largely focus on impairments to domain-general reasoning. Nevertheless, current rationality-impairment models do not account for the fact that (a) equivalently irrational beliefs can be induced through adaptive social cognitive processes, reflecting social integration rather than impairment; (b) delusions are overwhelmingly socially themed; and (c) delusions show a reduced sensitivity to social context both in terms of how they are shaped and how they are communicated. Consequently, we argue that models of delusions need to include alteration to coalitional cognition—processes involved in affiliation, group perception, and the strategic management of relationships. This approach has the advantage of better accounting for both content (social themes) and form (fixity) of delusion. It is also supported by the established role of mesolimbic dopamine in both delusions and social organization and the ongoing reconceptualization of belief as serving a social organizational function.

Looking into a Deluded Brain through a Neuroimaging Lens

Delusions are irrational, tenacious, and incorrigible false beliefs that are the most common symptom of a range of brain disorders including schizophrenia, Alzheimer's, and Parkinson's disease. In the case of schizophrenia and other primary delusional disorders, their appearance is often how the disorder is first detected and can be sufficient for diagnosis. At this time, not much is known about the brain dysfunctions leading to delusions, and hindering our understanding is that the complexity of the nature of delusions, and their very unique relevance to the human experience has hampered elucidation of their underlying neurobiology using either patients or animal models. Advances in neuroimaging along with improved psychiatric and cognitive modeling offers us a new opportunity to look with more investigative power into the deluded brain. In this article, based on data obtained from neuroimaging studies, we have attempted to draw a picture of the neural networks involved when delusion is present and evaluate whether different manifestations of delusions engage different regions of the brain.

Catching the imposter in the brain: The case of Capgras delusion

Here we describe a rare case of Capgras delusion - a misidentification syndrome characterized by the belief that a person has been replaced by an imposter - in a patient without evident neurological or psychiatric symptoms. Intriguingly, delusional belief was selective for both person and modality, as the patient believed that his son - not his daughter or other relatives - was substituted with an imposter only while being in presence of him and looking at his face, but not when merely listening to his voice. A neuroanatomical reconstruction obtained integrating morphological and functional patient's neuroimaging data highlighted two main peculiarities: a compression of the rostral portion of right temporal lobe due to a large arachnoid cyst, and a bilaterally reduced metabolism of frontal areas. Autonomic data obtained from thermal infra-red camera and skin conductance recordings showed that a higher sympathetic activation was evoked by the observation of daughter's face, relative to the observation of the son's face as well as of not-familiar faces; conversely, daughter and son voices elicited a similar sympathetic activation, higher relative to not-familiar voices, indicating a modality-dependent dissociation consistent with the delusional behavior. Our case supports the "two-hit hypothesis" about Capgras delusion etiopathogenesis: here, the first hit is represented by the right-temporal lesion impairing the association between familiar faces and emotional values, the second one is the frontal bilateral hypometabolism favoring delusional behavior. The selective occurrence of "imposter" delusion for a particular subject and for a specific perceptual modality suggests the involvement of modality-specific interactions in the retrieval of affective properties during familiar people recognition.

Moral cognition, the missing link between psychotic symptoms and acts of violence: a cross-sectional national forensic cohort study

BACKGROUND

People with schizophrenia are ten times more likely to commit homicide than a member of the general population. The relationship between symptoms of schizophrenia and acts of violence is unclear. There has also been limited research on what determines the seriousness and form of violence, such as reactive or instrumental violence. Moral cognition may play a paradoxical role in acts of violence for people with schizophrenia. Thoughts which have moral content arising from psychotic symptoms may be a cause of serious violence.

METHOD

We investigated if psychotic symptoms and moral cognitions at the time of a violent act were associated with acts of violence using a cross-sectional national forensic cohort (n = 55). We examined whether moral cognitions were associated with violence when controlling for neurocognition and violence proneness. We explored the association between all psychotic symptoms present at the time of the violent act, psychotic symptoms judged relevant to the violent act and moral cognitions present at that time. Using mediation analysis, we examined whether moral cognitions were the missing link between symptoms and the relevance of symptoms for violence. We also investigated if specific moral cognitions mediated the relationship between specific psychotic symptoms, the seriousness of violence (including homicide), and the form of violence.

RESULTS

Psychotic symptoms generally were not associated with the seriousness or form of violence. However, specific moral cognitions were associated with the seriousness and form of violence even when controlling for neurocognition and violence proneness. Specific moral cognitions were associated with specific psychotic symptoms present and relevant to violence. Moral cognitions mediated the relationship between the presence of specific psychotic symptoms and their relevance for violence, homicide, seriousness of violence, and the form of violence.

CONCLUSIONS

Moral cognitions including the need to reduce suffering, responding to an act of injustice or betrayal, the desire to comply with authority, or the wish to punish impure or disgusting behaviour, may be a key mediator explaining the relationship between psychotic symptoms and acts of violence. Our findings may have important implications for risk assessment, treatment and violence prevention.

Affective prosody and facial emotion recognition in first-episode schizophrenia: Associations with functioning & symptoms

Studies indicate that people with schizophrenia experience deficits in their ability to accurately detect emotions, both through facial expressions and voice intonation (i.e., prosody), and that functioning and symptoms are associated with these deficits. This study aimed to examine how facial emotion and affective prosody recognition are related to functioning and symptoms in a first-episode schizophrenia sample. Further, in light of research suggesting variable emotion-specific performance in people with schizophrenia, this study explored emotion-specific performance. Participants were 49 people with a recent first episode of schizophrenia taking part in a larger RCT. Results revealed that affective prosody recognition was significantly correlated with both role and social functioning. Regarding associations with psychiatric symptoms, facial emotion recognition was significantly, negatively associated with all three positive symptom scales, whereas affective prosody recognition was significantly, negatively associated with disorganization only. Emotion-specific analyses revealed that for affective prosody, participants were most accurate in recognizing anger and least accurate for disgust. For facial emotion recognition, participants were most accurate in recognizing happiness and least accurate for fear. Taken together, results suggest that affective prosody recognition is important for social and role functioning in people with first-episode schizophrenia. Results also suggest that this group may struggle more to identify negative emotions, though additional work is needed to clarify this pattern in affective prosody and determine real-world impact on social interactions.

Capturing behavioral indicators of persecutory ideation using mobile technology

Most existing measures of persecutory ideation (PI) rely on infrequent in-person visits, and this limits their ability to assess rapid changes or real-world functioning. Mobile health (mHealth) technology may address these limitations. Little is known about passively sensed behavioral indicators associated with PI. In the current study, sixty-two participants with schizophrenia spectrum disorders completed momentary assessments of PI on a smartphone that also passively collected behavioral data for one year. Results suggested that PI was prevalent (n = 50, 82% of sample) but had infrequent incidence (25.2% of EMA responses). PI was also associated with changes in several passively sensed variables, including decreases in distance traveled (M_kilometers = -1.20, SD = 18.88), time spent in a vehicle (M_minutes = -4.15, SD = 49.59), length of outgoing phone calls (M_minutes = -0.79, SD = 13.13), time spent proximal to human speech (M_minutes = -6.26, SD = 153.03), and an increase in time sitting still (M_minutes = 4.04, SD = 94.69). The present study suggests changes associated with PI may be detectable by passive sensors, including reductions in moving or traveling, and time spent around others or in self-initiated phone conversations. These constructs might constitute risk for PI.

Cognitive neuropsychiatric analysis of an additional large Capgras delusion case series

INTRODUCTION

Although important to cognitive neuropsychiatry and theories of delusions, Capgras delusion has largely been reported in single case studies. Bell et al. [2017. Uncovering Capgras delusion using a large scale medical records database. British Journal of Psychiatry Open, 3(4), 179-185] previously deployed computational and clinical case identification on a large-scale medical records database to report a case series of 84 individuals with Capgras delusion. We replicated this approach on a new database from a different mental health service provider while additionally examining instances of violence, given previous claims that Capgras is a forensic risk.

METHODS

We identified 34 additional cases of Capgras. Delusion phenomenology, clinical characteristics, and presence of lesions detected by neuroimaging were extracted.

RESULTS

Although most cases involved misidentification of family members or partners, a notable minority (20.6%) included the misidentification of others. Capgras typically did not present as a monothematic delusion. Few cases had identifiable lesions with no evidence of right-hemisphere bias. There was no evidence of physical violence associated with Capgras.

CONCLUSIONS

Findings closely replicate Bell et al. (2017). The majority of Capgras delusion phenomenology conforms to the "dual route" model although a significant minority of cases cannot be explained by this framework.

Exploring the relationship between fantasy proneness and delusional beliefs in psychosis and non-clinical individuals

Delusions are a core feature of psychopathology while fantasy proneness (FP) is a trait that describes a predisposition towards fantastical thinking, vivid mental imagery and an overactive imagination. The relationship between FP and delusional experiences has not yet been examined in the literature. The current study hypothesised that FP would be significantly associated with and predict delusion severity as well as the associated delusional distress, preoccupation and conviction. Ninety-five patients with current psychosis (schizophrenia and bipolar I disorder) were assessed for overall delusional severity using the PANSS (clinician-rated) and the Peters Delusions Inventory (PDI; self-report). FP was assessed using the Creative Experiences Questionnaire (CEQ). Forty-six healthy control participants also completed the PDI and CEQ. Significant positive correlations were observed between FP and delusion severity in both groups; and distress, preoccupation and conviction in patients only. Linear regression analyses, controlling for manic and depressive symptoms, revealed that greater FP predicted higher levels of severity, distress, preoccupation, and conviction associated with delusions in patients, and higher severity only in healthy controls. The findings highlight the role of specific cognitive biases in delusional experiences, and empirically support models of unusual belief formation and maintenance.

Understanding the Delusion of Theft

The elderly with dementing illness often present with psychotic symptoms such as delusions, but the thematic content of delusions in the elderly differs from that of delusions expressed by younger individuals, and can be pathognomonic of early dementia. The aim of this paper is to review the recent literature on the delusion of theft, the most prevalent delusion in the elderly, in order to arrive at a deeper understanding of its sources and to identify successful therapeutic approaches. The literature from 2000 to the present was searched on the Google Scholar database using relevant search terms. Several older classical papers were also referenced. Understanding the origins of the delusion of theft - multiple losses, attempts at attributing such losses to an outside source, attempts at reliving a happier past - helps in devising responses that are comforting to the patient. The distress that often accompanies the delusion of having been robbed can be decreased by nursing home improvements in the handling of personal possessions, by the correction of sensory deficits, and by the provision of activities that distract from loneliness. Attention to stimuli that trigger the delusion helps to limit its occurrence. Medications may help, but can sometimes make matters worse. Understanding that delusional thinking can arise from sensory and cognitive deficits is critical to empathic caregiving and also to the lessening of caregiver burden.

Reduced scanning of salient facial features mediates the association between paranoia and emotion recognition

The vigilance-avoidance hypothesis of paranoia states that in paranoia visual attention is shifted away from threat-related stimuli. This may be an explanation for reduced scanning of salient facial features in psychosis and subsequently impaired emotion recognition. Here, we explored whether higher levels of paranoia would predict reduced visual attention to salient facial features and impaired emotion recognition and whether reduced visual attention to salient facial features mediates the association between paranoia and errors in emotion recognition. Participants with schizophrenia (SZ, n = 22) and healthy controls (HC, n = 19) completed questionnaire assessments of paranoia and negative symptoms and conducted an emotion recognition task comprised of dynamic facial stimuli. Additionally, visual attention (number of fixations) to salient facial features was assessed using eye-tracking. SZ made more errors in affect recognition than HC. Visual attention to salient facial features did not differ between SZ and HC but significantly mediated the significant association between paranoia and errors in the emotion recognition task in the complete sample. Negative symptoms also predicted errors in emotion recognition but this association was not mediated by visual attention. Our findings are in line with the avoidance-assumption of a vigilance-avoidance hypothesis of paranoia, in which correct facial emotion recognition is prevented due to an avoidance of salient facial features.

Cross Cultural Validation and Extension of the Clinical Assessment Interview for Negative Symptoms (CAINS) in the Chinese Context: Evidence from a Spectrum Perspective

The Clinical Assessment Interview for Negative Symptoms (CAINS) was designed in accordance with the recent theory and research in social affective neuroscience and to address the psychometric and conceptual limitations of other instruments assessing negative symptoms. The present study aimed to provide a large-scale validation of the CAINS in China and examine its applicability and validity evidence across the schizophrenia spectrum. Using confirmatory factor analysis, our results replicated the original findings in the US development samples that the CAINS possesses a stable 2-factor structure, namely "motivation/pleasure" and "expression". We also found significant correlations between the CAINS and other negative symptom measures. The CAINS demonstrated good discriminant validity in differentiating negative symptoms in people with schizophrenia, nonpsychotic first-degree relatives and people with social anhedonia. People with schizophrenia exhibited significantly higher CAINS subscale scores than first-degree relatives and healthy controls. In addition, first-degree relatives had higher "motivation/pleasure" scores than healthy controls. The "motivation/pleasure" subscale scores of individuals with social anhedonia were also significantly higher than healthy controls.

Psychiatric Symptom Dimensions Are Associated With Dissociable Shifts in Metacognition but Not Task Performance

BACKGROUND

Distortions in metacognition-the ability to reflect on and control other cognitive processes-are thought to be characteristic of poor mental health. However, it remains unknown whether such shifts in self-evaluation are due to specific alterations in metacognition and/or a downstream consequence of changes in decision-making processes.

METHODS

Using perceptual decision making as a model system, we employed a computational psychiatry approach to relate parameters governing both decision formation and metacognitive evaluation to self-reported transdiagnostic symptom dimensions in a large general population sample (N = 995).

RESULTS

Variability in psychopathology was unrelated to either speed or accuracy of decision formation. In contrast, leveraging a dimensional approach, we revealed independent relationships between psychopathology and metacognition: a symptom dimension related to anxiety and depression was associated with lower confidence and heightened metacognitive efficiency, whereas a dimension characterizing compulsive behavior and intrusive thoughts was associated with higher confidence and lower metacognitive efficiency. Furthermore, we obtained a robust double dissociation-whereas psychiatric symptoms predicted changes in metacognition but not decision performance, age predicted changes in decision performance but not metacognition.

CONCLUSIONS

Our findings indicate a specific and pervasive link between metacognition and mental health. Our study bridges a gap between an emerging neuroscience of decision making and an understanding of metacognitive alterations in psychopathology.

From Believing to Belief: A General Theoretical Model

Cognitive neuroscience research has begun to explore the mental processes underlying what a belief and what believing are. Recent evidence suggests that believing involves fundamental brain functions that result in meaningful probabilistic representations, called beliefs. When relatively stable, these beliefs allow for guidance of behavior in individuals and social groups. However, they are also fluid and can be modified by new relevant information, interpersonal contact, social pressure, and situational demands. We present a theoretical model of believing that can account for the formation of both empirically grounded and metaphysical beliefs.

Early onset first episode psychosis: dimensional structure of symptoms, clinical subtypes and related neurodevelopmental markers

Despite the growing interest in a dimensional approach to the assessment of symptoms and clinically relevant phenomena in schizophrenia spectrum disorders, very few studies, to date, have examined the dimensional structure of symptoms in early onset first episode psychosis. In the present study, we assessed a sample of 60 children and adolescents of both sexes with first episode schizophrenia spectrum psychosis. A principal component analysis (PCA) of the Positive and Negative Syndrome Scale (PANSS) was performed and the factors obtained were used to carry out a cluster analysis. Sex, age of onset before or after 13, markers of early neurodevelopmental impairment and intellectual disabilities were considered as variables to characterized potential clinical subtypes, applying a one-way analysis of variance. Four factors were extracted ("negative symptoms", "delusions", "conceptual disorganization" and "paranoid/hostility"), each of them identifying a discrete clinical subtype of patients. No difference was found among the groups about sex and age of onset; delayed speech/language development was significantly associated with the "delusions" subtype and both "conceptual disorganization" and "delusions" subtypes showed a lower intelligence quotient (IQ). The four factors model we presented highlights "negative symptoms" as the most consistent factor; among positive symptoms, unusual thought content and conceptual disorganization resulted more distinctive of psychosis, at this age range, than perceptual abnormalities. Evolutionary trajectories of the four clinical subtypes we obtained seem to be influenced by cognitive and neurodevelopmental impairment rather than sex and age of onset.

Characteristics of memories of delusion-like experiences within the psychosis continuum: Pilot studies providing new insight on the relationship between self and delusions

BACKGROUND AND OBJECTIVES

Delusions are usually anchored in past events associated with abnormal experiences or delusional interpretations of personal events. The characteristics of the memory of these experiences may contribute to maintain delusional beliefs by providing confirmatory evidence for the delusions. However, these aspects have not been investigated properly.

METHOD

Seventeen patients with schizophrenia were examined in study 1 during a face-to-face interview. The second study used a web-based design and included 83 participants without a psychotic disorder. Participants were asked to rate the vividness, emotional intensity and valence, and the centrality to the self of memories of delusion-like experiences (that were cued by means of the Peters et al. Delusional Inventory, PDI; Peters, Joseph, Day, & Garety, 2004) and positive and negative memories used as comparators.

RESULTS

In both studies, the memories of delusion-like experiences were less vivid, less emotionally intense than positive (but not negative) memories and emotionally neutral. Their centrality to the self did not differ from that of positive and negative memories. Moreover, the severity of delusions in study 1 and delusion-proneness in study 2 were significantly correlated with vividness, emotional intensity, and centrality of memories of delusion-like experiences.

LIMITATIONS

The accuracy of memories of delusion-like experiences could not be checked making it difficult to distinguish them from delusional memories. The sample size was small in study 1.

CONCLUSIONS

Our results point to reciprocal relationships between delusions, self, and autobiographical memories of delusion-like experiences that are similar within the psychosis continuum and that may be involved in the maintenance of delusions.

Invariance of factor structure of the 21-item Peters et al. Delusions Inventory (PDI-21) over time and across samples

The present study aimed to explore the latent structure of the 21-item Peters et al. Delusions Inventory (PDI-21) and to test the invariance of its factor structure over time and across samples. The PDI-21 was administered in two samples; one consisting of 1655 undergraduate students investigated in three waves, each separated by six months; and another consisting of 196 outpatients with schizophrenia. Exploratory factor analysis was performed to explore the internal structure of the PDI-21 based on number of beliefs and the grand total scores separately. The number of factors was determined by optimal implementation of parallel analysis. Confirmatory factor analysis, cross-time and cross-sample invariance analyses were carried out with Mplus. Both exploratory factor analysis and the optimal implementation of parallel analysis (based on the number of beliefs and the total score of the PDI-21) suggested a one-factor solution. However, the confirmatory factor analysis revealed a single-dimension structure based on number of beliefs only, which exhibited goodness of fit and stability across time and samples. Our study demonstrated a single-dimension structure of the PDI-21, which can be widely used in screening the number of delusional ideations both in clinical and non-clinical populations.

A conditioning model of delusion

"Delusions" are beliefs that are false and persistent. It is suggested here that these characteristics can emerge from interplays between two fundamental learning processes: (1) the allocation of attentional resources among stimuli; and (2) the effects of feedback on learning. The former of these has been operationalized in the learned irrelevance and latent inhibition paradigms; the latter in studies of the effects of persistence-training. Normally, the attentional process functions to constrain persistence-training effects so that only valid associations acquire persistence. But when persistence-training is less influenced in this way, its mechanisms can interact with a noisy environment to gradually insulate maladaptive associations from disconfirming feedback. When unchecked, these dynamics likely lead to a systematic distortion of beliefs that can become increasingly persistent regardless of their validity. Delusions are therefore predicted to tend to arise whenever the balance of (1) is weakened in favour of (2), whether by experimental manipulation, trait-related factors, cultural causes or evolutionary history. Existing evidence is consistent with the model and further implications are discussed.

Immersion in altered experience: An investigation of the relationship between absorption and psychopathology

Understanding alterations in perceptual experiences as a component of the basic symptom structure of psychosis may improve early detection and the identification of subtle shifts that can precede symptom onset or exacerbation. We explored the phenomenological construct of absorption and psychotic experiences in both clinical (bipolar psychosis and schizophrenia spectrum) and non-clinical participants. Participants with psychosis endorsed significantly higher absorption compared to the non-clinical group. Absorption was positively correlated with all types of hallucinations and multiple types of delusions. The analysis yielded two distinct cluster groups that demarcated a distinction along the continuum of self-disturbance: on characterized by attenuated ego boundaries and the other stable ego boundaries. The study suggests that absorption is a potentially important but under-researched component of psychosis that overlaps with, but is not identical to the more heavily theorized constructs of aberrant salience and hyperreflexivity.

Reasoning in psychosis: risky but not necessarily hasty

INTRODUCTION

A liberal acceptance (LA) threshold for hypotheses has been put forward to explain the well-replicated "jumping to conclusions" (JTC) bias in psychosis, particularly in patients with paranoid symptoms. According to this account, schizophrenia patients rest their decisions on lower subjective probability estimates. The initial formulation of the LA account also predicts an absence of the JTC bias under high task ambiguity (i.e., if more than one response option surpasses the subjective acceptance threshold).

METHODS

Schizophrenia patients (n = 62) with current or former delusions and healthy controls (n = 30) were compared on six scenarios of a variant of the beads task paradigm. Decision-making was assessed under low and high task ambiguity. Along with decision judgments (optional), participants were required to provide probability estimates for each option in order to determine decision thresholds (i.e., the probability the individual deems sufficient for a decision).

RESULTS

In line with the LA account, schizophrenia patients showed a lowered decision threshold compared to controls (82% vs. 93%) which predicted both more errors and less draws to decisions. Group differences on thresholds were comparable across conditions. At the same time, patients did not show hasty decision-making, reflecting overall lowered probability estimates in patients.

CONCLUSIONS

Results confirm core predictions derived from the LA account. Our results may (partly) explain why hasty decision-making is sometimes aggravated and sometimes abolished in psychosis. The proneness to make risky decisions may contribute to the pathogenesis of psychosis. A revised LA account is put forward.

Acceptance and Efficacy of Metacognitive Training (MCT) on Positive Symptoms and Delusions in Patients With Schizophrenia: A Meta-analysis Taking Into Account Important Moderators

Metacognitive training (MCT) is a new, widely used intervention for psychosis. The present meta-analysis examines the efficacy of MCT in schizophrenia. Fifteen studies comparing effects of MCT on positive symptoms, delusions or acceptance of MCT with a control group were included in this meta-analysis. These studies comprised a total of 408 patients in the MCT condition and 399 in the control condition. The moderating effects of masking of outcome assessment, randomization, incomplete outcome data, use of an active control intervention, and individual vs group MCT were investigated. Possible effects of sensitivity analyses and publication bias were also examined. The results show a significant overall effect of MCT for positive symptoms (g = -0.34, 95% CI [-0.53, -0.15]), delusions (g = -0.41, 95% CI [-0.74, -0.07]) and acceptance of the intervention (g = -0.84, 95% CI [-1.37, -0.31]). Using only studies being at low risk for bias regarding randomization, masking and incomplete outcome data reduced effect sizes for positive symptoms and delusions (g = -0.28, 95% CI [-0.50, -0.06] and g = -0.18, 95% CI [-0.43, 0.06]), respectively. This meta-analysis demonstrates that MCT exerts a small to moderate effect on delusions and positive symptoms and a large effect on acceptance of the intervention. The effect on delusions is reduced, but remains significant when potential biases are considered.

The erotetic theory of delusional thinking

INTRODUCTION

In this paper, we argue for a novel account of one cognitive factor implicated in delusional cognition. According to the erotetic theory of delusion we present, the central cognitive factor in delusion is impaired endogenous question raising.

METHOD

After presenting the erotetic theory, we draw on it to model three distinct patterns of reasoning exhibited by delusional and schizophrenic patients, and contrast our explanations with Bayesian alternatives.

RESULTS

We argue that the erotetic theory has considerable advantages over Bayesian models. Specifically, we show that it offers a superior explanation of three phenomena: the onset and persistence of the Capgras delusion; recent data indicating that schizophrenic subjects manifest superior reasoning with conditionals in certain contexts; and evidence that schizophrenic and delusional subjects have a tendency to "jump to conclusions." Moreover, since the cognitive mechanisms we appeal to are independently motivated, we avoid having to posit distinct epistemic states that are intrinsically irrational in order to fit our model to the variety of data.

CONCLUSION

In contrast to Bayesian models, the erotetic theory offers a simple, unified explanation of a range of empirical data. We therefore conclude that it offers a more plausible framework for explaining delusional cognition.

Investigating the efficacy of an individualized metacognitive therapy program (MCT+) for psychosis: study protocol of a multi-center randomized controlled trial

BACKGROUND

Psychological interventions are increasingly recommended as adjunctive treatments for psychosis, but their implementation in clinical practice is still insufficient. The individualized metacognitive therapy program (MCT+; www.uke.de/mct_plus ) represents a low-threshold psychotherapeutic approach that synthesizes group metacognitive training (MCT) and cognitive behavioral therapy for psychosis, and addresses specific cognitive biases that are involved in the onset and maintenance of psychosis. It aims to "plant the seed of doubt" regarding rigid delusional convictions and to encourage patients to critically reflect, extend and change their approach to problem solving. Its second edition also puts more emphasis on affective symptoms. A recent meta-analysis of metacognitive interventions (MCT, MCT+) indicate small to moderate effects on positive symptoms and delusions, as well as high rates of acceptance. Nonetheless, no long-term studies of MCT+ involving large samples have been conducted.

METHODS

The goal of the present multi-center, observer-blind, parallel-group, randomized controlled trial is to compare the efficacy of MCT+ against an active control (cognitive remediation; MyBrainTraining(©)) in 328 patients with psychosis at three time points (baseline, immediately after intervention [6 weeks] and 6 months later). The primary outcome is change in psychosis symptoms over the 6-month follow-up period as assessed by the delusion subscale of the Psychotic Symptom Rating Scale. Secondary outcomes include jumping to conclusions, other positive symptoms of schizophrenia, depressive symptoms, self-esteem, quality of life, and cognitive insight. The study also seeks to elucidate mediating factors that promote versus impede symptom improvement across time.

DISCUSSION

This is the first multi-center randomized controlled trial to test the efficacy of individualized MCT+ in a large sample of patients with psychosis. The rationale for the trial, the design, and the strengths and limitations of the study are discussed.

TRIAL REGISTRATION

The trial is registered through the German Clinical Trials Register ( www.drks.de ) as DRKS00008001 . Registered 6 May 2015.

Role of the first and second person perspective for control of behaviour: Understanding other people's facial expressions

Humans typically make probabilistic inferences about another person's affective state based on her/his bodily movements such as emotional facial expressions, emblematic gestures and whole body movements. Furthermore, humans deduce tentative predictions about the other person's intentions. Thus, the first person perspective of a subject is supplemented by the second person perspective involving theory of mind and empathy. Neuroimaging investigations have shown that the medial and lateral frontal cortex are critical nodes in the circuits underlying theory of mind, empathy, as well as intention of action. It is suggested that personal perspective taking in social interactions is paradigmatic for the capability of humans to generate probabilistic accounts of the outside world that underlie a person's control of behaviour.

Factors contributing to social cognition impairment in borderline personality disorder and schizophrenia

Social cognition (SC) deficits have been described both in patients with schizophrenia and borderline personality disorder (BPD). However, while the former tend towards simplistic mental state attributions (undermentalizing), the latter are more likely to make overly complex mental state inferences (overmentalizing). Performance on complex SC tasks has been shown to correlate with neurocognitive ability, emotion perception, a history of trauma, and overconfidence in errors. However, it is unclear how these factors relate to different aspects of SC deficits. Aim of the present study was to examine the pathways of SC impairment by investigating performance profiles and their predictors comparatively in BPD and schizophrenia. Participants were 44 patients with BPD, 36 patients with schizophrenia, and 38 healthy controls. Undermentalizing and overmentalizing were assessed with an ecologically valid SC task. Patients with BPD exhibited increased overmentalizing, whereas patients with schizophrenia showed a more extensive deficit pattern, their main error type being undermentalizing. Overconfidence in errors was the most important predictor for overmentalizing, while undermentalizing depended mainly on verbal memory and emotion perception. Thus, BPD und schizophrenia exhibited different SC impairment patterns, and different types of SC errors were predicted by different factors. These findings have implications for the optimization of treatment approaches.

Using Intermediate Cognitive Endpoints to Facilitate Translational Research in Psychosis

Recent advances in the understanding of psychosis have uncovered potential for a paradigm shift in related drug discovery efforts. The study of psychosis is evolving from its origins in serendipity and empiricism to more formal, hypothesis driven accounts of the cognitive substrates underlying hallucinations and delusions. Recent evidence suggests that misattribution of salience and abnormal prediction error might underlie some forms of psychosis. If substantiated, such intermediate constructs could significantly facilitate translational research for drug discovery. Aberrant salience and prediction error can be assayed with simple tests of associative learning in both species, and a convincing back translation of effects, when combined with measures of neurotransmitter release and brain activity could for the first time allow robust, causal connections to be made between molecular mechanisms in rodents and symptoms in patients.

Metacognitive therapy (MCT+) in patients with psychosis not receiving antipsychotic medication: A case study

Background: Psychotherapies for psychosis typically aim to develop an awareness of the implausible content of a delusion or target the underlying cognitive biases (i.e., problematic thinking styles, such as hasty decisions and illusory control) that foster and maintain delusional beliefs. A recently designed individual-based treatment entitled metacognitive therapy (MCT+) combines these two approaches. Emerging evidence suggests individualized MCT+, when used concurrently with antipsychotic medication, may be an effective psychological treatment for reducing delusional symptoms. However, it remains to be tested whether MCT+ can be effective in patients with active delusions who are not currently receiving psychotropic drugs.

Method: We present two cases (one patient with schizophrenia and the other with delusional disorder) experiencing active delusions who underwent 4-weeks of intensive MCT+, without concurrent antipsychotic medication (minimum 6-months unmedicated). Baseline and 6-week follow-up data are presented on a variety of measures assessing delusion symptom severity (i.e., PANSS, PSYRATS, SAPS), clinical insight, and cognitive bias propensity.

Results: After 4-weeks of MCT+, both patients showed substantial reduction in delusional symptoms, reported improved clinical insight, and were less prone to making illusory correlations.

Conclusions: The presented case studies provide preliminary evidence for the feasibility of MCT+ in treating patients not taking, or resistant to, antipsychotic medication.

Investigating the usefulness of a metacognitive training group programme for schizophrenia

Aims and method To examine the usefulness of a cognitive-behavioural therapy-based group intervention, metacognitive training for schizophrenia (MCT), in a 'real-world' clinical setting. In total, 164 participants completed 327 questionnaires at the end of MCT group sessions; rating the perceived usefulness, helpfulness to recovery, change in knowledge and anxiety. Non-parametric statistical tests were used to analyse the data. Results Participants indicated positive responses in terms of perceived usefulness, helpfulness to recovery and increased knowledge following group attendance. Significant positive correlations were found between: (a) usefulness and helpfulness to recovery, and (b) helpfulness to recovery and change in knowledge. There were significant negative correlations between: (a) usefulness and anxiety, and (b) helpfulness to recovery and anxiety. Clinical implications The results suggest that MCT is a useful and effective evidence-based psychological intervention. It supports the use of cognitive-behavioural interventions in the treatment of individuals experiencing psychosis, although further evaluation is needed.

Associations between visual perception accuracy and confidence in a dopaminergic manipulation study

Delusions are defined as fixed erroneous beliefs that are based on misinterpretation of events or perception, and cannot be corrected by argumentation to the opposite. Cognitive theories of delusions regard this symptom as resulting from specific distorted thinking styles that lead to biased integration and interpretation of perceived stimuli (i.e., reasoning biases). In previous studies, we were able to show that one of these reasoning biases, overconfidence in errors, can be modulated by drugs that act on the dopamine system, a major neurotransmitter system implicated in the pathogenesis of delusions and other psychotic symptoms. Another processing domain suggested to involve the dopamine system and to be abnormal in psychotic disorders is sensory perception. The present study aimed to investigate whether (lower-order) sensory perception and (higher-order) overconfidence in errors are similarly affected by dopaminergic modulation in healthy subjects. Thirty-four healthy individuals were assessed upon administration of l-dopa, placebo, or haloperidol within a randomized, double-blind, cross-over design. Variables of interest were hits and false alarms in an illusory perception paradigm requiring speeded detection of pictures over a noisy background, and subjective confidence ratings for correct and incorrect responses. There was a significant linear increase of false alarm rates from haloperidol to placebo to l-dopa, whereas hit rates were not affected by dopaminergic manipulation. As hypothesized, confidence in error responses was significantly higher with l-dopa compared to placebo. Moreover, confidence in erroneous responses significantly correlated with false alarm rates. These findings suggest that overconfidence in errors and aberrant sensory processing might be both interdependent and related to dopaminergic transmission abnormalities in patients with psychosis.