Derationalizing Delusions

Dopamine and serotonin in human substantia nigra track social context and value signals during economic exchange

Dopamine and serotonin are hypothesized to guide social behaviours. In humans, however, we have not yet been able to study neuromodulator dynamics as social interaction unfolds. Here, we obtained subsecond estimates of dopamine and serotonin from human substantia nigra pars reticulata during the ultimatum game. Participants, who were patients with Parkinson's disease undergoing awake brain surgery, had to accept or reject monetary offers of varying fairness from human and computer players. They rejected more offers in the human than the computer condition, an effect of social context associated with higher overall levels of dopamine but not serotonin. Regardless of the social context, relative changes in dopamine tracked trial-by-trial changes in offer value-akin to reward prediction errors-whereas serotonin tracked the current offer value. These results show that dopamine and serotonin fluctuations in one of the basal ganglia's main output structures reflect distinct social context and value signals.

Visualizing threat and trustworthiness prior beliefs in face perception in high versus low paranoia

Predictive processing accounts of psychosis conceptualize delusions as overly strong learned expectations (prior beliefs) that shape cognition and perception. Paranoia, the most prevalent form of delusions, involves threat prior beliefs that are inherently social. Here, we investigated whether paranoia is related to overly strong threat prior beliefs in face perception. Participants with subclinical levels of high (n = 109) versus low (n = 111) paranoia viewed face stimuli paired with written descriptions of threatening versus trustworthy behaviors, thereby activating their threat versus trustworthiness prior beliefs. Subsequently, they completed an established social-psychological reverse correlation image classification (RCIC) paradigm. This paradigm used participants' responses to randomly varying face stimuli to generate individual classification images (ICIs) that intend to visualize either facial prior belief (threat vs. trust). An independent sample (n = 76) rated these ICIs as more threatening in the threat compared to the trust condition, validating the causal effect of prior beliefs on face perception. Contrary to expectations derived from predictive processing accounts, there was no evidence for a main effect of paranoia. This finding suggests that paranoia was not related to stronger threat prior beliefs that directly affected face perception, challenging the assumption that paranoid beliefs operate on a perceptual level.

Self-Disorder in Schizophrenia: A Revised View (1. Comprehensive Review-Dualities of Self- and World-Experience)

A growing body of research supports the role of self-disorders as core phenotypic features of schizophrenia-spectrum disorders. Self-disorders comprise various alterations of conscious experience whose theoretical understanding continues to present a challenge. The following 2 articles aim to provide further clarification of the nature of self-disorders in schizophrenia by offering a comprehensive review (article 1) and theoretical revision (article 2) of the currently most influential model of altered selfhood in schizophrenia: the basic-self-disturbance or ipseity-disorder model (IDM). This article presents a state-of-the-art overview of the current self-disturbance model and critically assesses its descriptive adequacy with respect to the clinical variability and heterogeneity of the alterations in self- and world-awareness characteristic of schizophrenia. Special attention is paid to experiences of exaggerated basic self, increased "grip" or "hold" on the world, and paradoxical combinations. The next article proposes a theoretical revision of the self-disturbance model by considering how hyperreflexivity might form the crucial common thread or generating factor that unifies the phenomenologically heterogeneous, and sometimes even contradictory features of schizophrenic self-disorders. We outline the implications of our revised model for explanatory research, therapeutic practice, and our general understanding of the abnormalities in question.

The effects of paranoia and dopamine on perception of cohesion and conspiracy: a pre-registered, double-blind, placebo-controlled experiment

Paranoia is a common symptom of psychotic disorders but is also present on a spectrum of severity in the general population. Although paranoia is associated with an increased tendency to perceive cohesion and conspiracy within groups, the mechanistic basis of this variation remains unclear. One potential avenue involves the brain's dopaminergic system, which is known to be altered in psychosis. In this study, we used large-N online samples to establish the association between trait paranoia and perceptions of cohesion and conspiracy. We further evaluated the role of dopamine on perceptions of cohesion and conspiracy using a double-blind, placebo-controlled laboratory experiment where participants received levodopa or a placebo control. Our results were mixed: group perceptions and perceptions of cohesion were higher among more paranoid individuals but were not altered under dopamine administration. We outline the potential reasons for these discrepancies and the broader implications for understanding paranoia in terms of dopamine dysregulation.

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.

Excessive teleological thinking is driven by aberrant associations and not by failure of reasoning

Teleological thought - the tendency to ascribe purpose to objects and events - is useful in some cases (encouraging explanation-seeking), but harmful in others (fueling delusions and conspiracy theories). What drives excessive and maladaptive teleological thinking? In causal learning, there is a fundamental distinction between associative learning versus learning via propositional mechanisms. Here, we propose that directly contrasting the contributions of these two pathways can elucidate the roots of excess teleology. We modified a causal learning task such that we could encourage associative versus propositional mechanisms in different instances. Across three experiments (total N = 600), teleological tendencies were correlated with delusion-like ideas and uniquely explained by aberrant associative learning, but not by learning via propositional rules. Computational modeling suggested that the relationship between associative learning and teleological thinking can be explained by excessive prediction errors that imbue random events with more significance - providing a new understanding for how humans make meaning of lived events.

Developing and validating the Japanese version of the Referential Thinking Scale: A cross-sectional study

It has been shown that ideas of reference in the context of paranoia (IoR-P) and schizophrenia spectrum disorders (IoR-S) are caused by different psychological constructs. Although it is well known that both IoR-P and IoR-S are frequently evoked during the same period of life, how they interact with each other is unknown. The purpose of the present study was to develop the Japanese version of the Referential Thinking Scale (J-REF) to assess IoR-S, examine its validity and reliability, and explore the predictors of IoR-P and IoR-S. In this study, several subgroups of Japanese individuals in their 20s were included in the analysis. The J-REF had high internal consistency, high test-retest reliability, good convergent, and discriminant validity. Two hierarchical regression analyses showed that public self-consciousness predicted the manifestation of IoR-P, while the dimensions of schizotypy predicted that of IoR-S. Moreover, social anxiety and negative moods could cause IoR-P and IoR-S. This study directly showed the existence of two different types of ideas of reference in terms of their predictors. It is also significant in that it first examined referential thinking using the REF scale in the context of Asia and showed that there may not be much difference in the frequency of ideas of reference from other cultures. Future research directions are also discussed.

Differential Trajectories of Delusional Content and Severity Over 2 Years of Early Intervention for Psychosis: Comparison Between Chennai, India, and Montréal, Canada

BACKGROUND

There exist few direct studies of delusional content in psychosis across geo-cultural contexts, especially those in which treatment protocols and measures are comparable. To directly examine an illness outcome that is potentially culturally mediated, this study investigated the baseline presentation and longitudinal trajectory of delusions in first-episode psychosis (FEP) across 2 similar treatment settings in Montréal (Canada) and Chennai (India).

STUDY DESIGN

Patients entering an early intervention program for FEP in Chennai (N = 168) and Montréal (N = 165) were compared on site-level differences in the presentation of delusions across specific time points over 2 years of treatment. Delusions were measured using the Scale for Assessment of Positive Symptoms. Chi-square and regression analyses were conducted.

STUDY RESULTS

At baseline, delusions were more frequent in Montréal than in Chennai (93% vs 80%, respectively; X2(1) = 12.36, P < .001). Thematically, delusions of grandiosity, religiosity, and mind reading were more common in Montréal than in Chennai (all P < .001); however, these baseline differences did not persist over time. Regression revealed a significant time-by-site interaction in the longitudinal course of delusions, which differs from the trajectory of other FEP-positive symptom domains.

CONCLUSIONS

To the best of our knowledge, this is the first direct comparison of delusions in similar programs for FEP across 2 different geo-cultural contexts. Our findings support the notion that delusion themes follow consistent ordinal patterns across continents. Future work is needed to unpack the differences in severity that present at baseline and minor differences in content.

Paranoid thinking and perceived competitive intention

Paranoid thinking, that others are hostile, can be seen even in the general population. Paranoia is considered the expectation that others are competitors who aim to maximize the differences in payoffs rather than maximize their own payoffs. This study examined whether paranoia reflects the irrational belief that others have a competitive intention and is associated with avoiding perceived competition. We recruited 884 US residents via the Internet and conducted a modified Dictator Game, in which monetary allocation was carried out between the Dictator and the Recipient. The Dictator chooses either fair or competitive allocation while selecting the competitive allocation is irrelevant to increasing the Dictator's payoffs. The Recipient decides whether to accept the Dictator's decision or receive sure but low rewards. We found that Recipients with high-level paranoid thinking expected their opponent to select competitive allocation more than those with low levels, even when selecting it was costly for Dictators. Paranoid thinking was not associated with selecting sure rewards or competitive allocations. The results suggest that paranoia reflects the belief that others have a competitive intention but is not related to avoidance behavior against perceived threats and unilateral attacks.

Effectiveness of a Metacognitive Intervention for Schizophrenia (MCI-S) Program for Symptom Relief and Improvement in Social Cognitive Functioning in Patients with Schizophrenia

This study investigated the effectiveness of a metacognitive intervention program for symptom relief and improvement in social cognitive functioning among adults with schizophrenia. The program focused on enhancing metacognition to encourage self-awareness and step-by-step perspective expansion. There were 24 participants in the experimental group and 19 participants in the control group. Delusions decreased, and social cognition and social functioning improved in the experimental group compared to the control group. The program demonstrated utility as a treatment modality, which can be part of an overall program of a mental health promotion institution to improve functioning in patients with schizophrenia.

'An experience of meaning': A 20-year prospective analysis of delusional realities in schizophrenia and affective psychoses

Delusions are transdiagnostic and heterogeneous phenomena with varying degrees of intensity, stability, and dimensional attributes where the boundaries between everyday beliefs and delusional beliefs can be experienced as clearly demarcated, fuzzy, or indistinguishable. This highlights the difficulty in defining delusional realities. All individuals in the current study were evaluated at index and at least one of six subsequential follow-ups over 20 years in the Chicago Longitudinal Study. We assessed 16 distinct delusions categorized as thought or thematic delusions. We also examined the probability of recurrence and the relationships between delusions and hallucinations, depression, anxiety, and negative symptoms. The sample consisted of 262 individuals with schizophrenia vs. affective psychosis. Thought delusions were significantly different between groups at all follow-up evaluations except the 20-year timepoint. Thematic delusions were more common than thought delusions and show a significant decreasing pattern. In general, delusional content varied over time. Referential, persecutory, and thought dissemination delusions show the highest probability of recurrence. Hallucinations were the strongest indicator for thought, thematic, and overall delusions. The formation and maintenance of delusions were conceptualized as a multimodal construct consisting of sensory, perceptual, emotional, social, and somatic embodiment of an "experience of meanings". Given the significant associations between delusions and hallucinations, future work incorporating participatory research is needed to better define and align subjective and objective perspectives. Our research also points to the need for future clinical interventions that specifically evaluate and target the coexistence and entanglement of delusions and hallucinations.

Everything is connected: Inference and attractors in delusions

Delusions are, by popular definition, false beliefs that are held with certainty and resistant to contradictory evidence. They seem at odds with the notion that the brain at least approximates Bayesian inference. This is especially the case in schizophrenia, a disorder thought to relate to decreased - rather than increased - certainty in the brain's model of the world. We use an active inference Markov decision process model (a Bayes-optimal decision-making agent) to perform a simple task involving social and non-social inferences. We show that even moderate changes in some model parameters - decreasing confidence in sensory input and increasing confidence in states implied by its own (especially habitual) actions - can lead to delusions as defined above. Incorporating affect in the model increases delusions, specifically in the social domain. The model also reproduces some classic psychological effects, including choice-induced preference change, and an optimism bias in inferences about oneself. A key observation is that no change in a single parameter is both necessary and sufficient for delusions; rather, delusions arise due to conditional dependencies that create 'basins of attraction' which trap Bayesian beliefs. Simulating the effects of antidopaminergic antipsychotics - by reducing the model's confidence in its actions - demonstrates that the model can escape from these attractors, through this synthetic pharmacotherapy.

A Neural Circuit for Spirituality and Religiosity Derived From Patients With Brain Lesions

BACKGROUND

Over 80% of the global population consider themselves religious, with even more identifying as spiritual, but the neural substrates of spirituality and religiosity remain unresolved.

METHODS

In two independent brain lesion datasets (N₁ = 88; N₂ = 105), we applied lesion network mapping to test whether lesion locations associated with spiritual and religious belief map to a specific human brain circuit.

RESULTS

We found that brain lesions associated with self-reported spirituality map to a brain circuit centered on the periaqueductal gray. Intersection of lesion locations with this same circuit aligned with self-reported religiosity in an independent dataset and previous reports of lesions associated with hyper-religiosity. Lesion locations causing delusions and alien limb syndrome also intersected this circuit.

CONCLUSIONS

These findings suggest that spirituality and religiosity map to a common brain circuit centered on the periaqueductal gray, a brainstem region previously implicated in fear conditioning, pain modulation, and altruistic behavior.

Factors affecting conspiracy theory endorsement in paranoia

Paranoia and conspiracy thinking are known to be distinct but correlated constructs, but it is unknown whether certain types of conspiracy thinking are more common in paranoia than others. In a large (n = 1000), pre-registered online study we tested if endorsement of items on a new Components of Conspiracy Ideation Questionnaire varied according to whether harm was described as being (a) intentional and (b) self-referential. Our predictions were supported: paranoia was positively associated with endorsement of items on this questionnaire overall and more paranoid individuals were more likely to endorse items describing intentional and self-referential harm. Belief in any item on the Components of Conspiracy Ideation Questionnaire was associated with belief in others and items describing incidental harm and harm to others were found to be more believable overall. Individuals who endorsed conspiracy theory items on the questionnaire were more likely to state that people similar to them would as well, although this effect was not reduced in paranoia, counter to our expectations.

Conjecturing Harmful Intent and Preemptive Strike in Paranoia

Paranoia depicts a belief of others having harmful intent. Research using economic games has exhibited the correlation between paranoia and the propensity to characterize ambiguous intentions as harmful. Using a non-clinical sample recruited online from the United States (N=290), we examined whether paranoid thoughts influence aggressive behavior against the subjective perception of harmful intent. We conducted a preemptive strike game wherein aggressive behavior was assumed to be guided by the fear of an opponent. The outcomes indicate that (1) individuals with high paranoia assume harmful intent of an opponent more than those with low paranoia (2) conjecturing an opponent's harmful intent predicted an increase in the probability of a preemptive strike, and (3) paranoia did not have a statistically significant effect on encouraging a preemptive strike. Additionally, the exploratory analysis revealed that paranoia was related to participant's aggressiveness and with suppositions of other's self-interests and competitiveness. This study presents empirical evidence that paranoia is related to the perception of social threats in an uncertain situation. We discuss the possibility that paranoid ideation can promote or inhibit a preemptive strike.

Uncovering the realities of delusional experience in schizophrenia: a qualitative phenomenological study in Belgium

BACKGROUND

Delusions in schizophrenia are commonly approached as empirical false beliefs about everyday reality. Phenomenological accounts, by contrast, have suggested that delusions are more adequately understood as pertaining to a different kind of reality experience. How this alteration of reality experience should be characterised, which dimensions of experiential life are involved, and whether delusional reality might differ from standard reality in various ways is unclear and little is known about how patients with delusions value and relate to these experiential alterations. This study aimed to investigate the nature of delusional reality experience, and its subjective apprehension, in individuals with lived experience of delusions and a schizophrenia-spectrum diagnosis.

METHODS

In this qualitative phenomenological study, we recruited individuals with lived experience of delusions and a schizophrenia-spectrum diagnosis from two psychiatric-hospital services in Belgium using homogenous sampling. Criteria for participation were having undergone at least one psychotic episode with occurring delusional symptoms, present at least 1 year before participation, on the basis of clinical notes assessed by the attending psychiatrist; a schizophrenia-spectrum diagnosis, ascertained through clinical interview by the attending psychiatrist upon admission; being aged between 18 years and 65 years; and having the capacity to give informed consent. Exclusion criteria included worries concerning capacity to consent and risk of distress caused by participation. We did phenomenologically driven semi-structured interviews with the participants to explore the nature of delusional reality experience and their subjective valuation of these experiences. We used interpretative phenomenological analysis, a qualitative method tailored to the in-depth exploration of participants' first-person perspective, to analyse their accounts.

FINDINGS

Between March 2, 2020, and Sept 30, 2020, 18 adults (13 men and five women, aged 19-62 years) participated in the interview study. The findings suggest that delusions are often embedded in wide-ranging alterations of basic reality experience, involving quasi-ineffable atmospheric and ontological qualities that undermine participants' sense of the world as unambiguously real, fully present, and shared with others. We also found that delusional reality experience can differ from standard reality in various ways (ie, in a hypo-real and hyper-real form), across multiple dimensions (eg, meaningfulness, necessity and contingency, and detachment and engagement), and that participants are often implicitly or explicitly aware of the distinction between delusional and standard reality. Delusional experience can have an enduring value and meaning that is not fully captured by a strictly medical perspective.

INTERPRETATION

Increased awareness and recognition of the distinctive nature of delusional reality experience, in both clinical and research settings, can improve diagnostic accuracy, explanatory models, and therapeutic support for individuals with delusions whose lived realities are not always evident from an everyday perspective.

FUNDING

FWO Flanders.

TRANSLATION

For the Dutch translation of the abstract see Supplementary Materials section.

Taking others into account: combining directly experienced and indirect information in schizophrenia

An abnormality in inference, resulting in distorted internal models of the world, has been argued to be a common mechanism underlying the heterogeneous psychopathology in schizophrenia. However, findings have been mixed as to wherein the abnormality lies and have typically failed to find convincing relations to symptoms. The limited and inconsistent findings may have been due to methodological limitations of the experimental design, such as conflating other factors (e.g. comprehension) with the inferential process of interest, and a failure to adequately assess and model the key aspects of the inferential process. Here, we investigated probabilistic inference based on multiple sources of information using a new digital version of the beads task, framed in a social context. Thirty-five patients with schizophrenia or schizoaffective disorder with a wide range of symptoms and 40 matched healthy control subjects performed the task, where they guessed the colour of the next marble drawn from a jar based on a sample from the jar as well as the choices and the expressed confidence of four people, each with their own independent sample (which was hidden from participant view). We relied on theoretically motivated computational models to assess which model best captured the inferential process and investigated whether it could serve as a mechanistic model for both psychotic and negative symptoms. We found that 'circular inference' best described the inference process, where patients over-weighed and overcounted direct experience and under-weighed information from others. Crucially, overcounting of direct experience was uniquely associated with most psychotic and negative symptoms. In addition, patients with worse social cognitive function had more difficulties using others' confidence to inform their choices. This difficulty was related to worse real-world functioning. The findings could not be easily ascribed to differences in working memory, executive function, intelligence or antipsychotic medication. These results suggest hallucinations, delusions and negative symptoms could stem from a common underlying abnormality in inference, where directly experienced information is assigned an unreasonable weight and taken into account multiple times. By this, even unreliable first-hand experiences may gain disproportionate significance. The effect could lead to false perceptions (hallucinations), false beliefs (delusions) and deviant social behaviour (e.g. loss of interest in others, bizarre and inappropriate behaviour). This may be particularly problematic for patients with social cognitive deficits, as they may fail to make use of corrective information from others, ultimately leading to worse social functioning.

Religion and delusion

We review scholarship that examines relationships - and distinctions - between religion and delusion. We begin by outlining and endorsing the position that both involve belief. Next, we present the prevailing psychiatric view that religious beliefs are not delusional if they are culturally accepted. While this cultural exemption has controversial implications, we argue it is clinically valuable and consistent with a growing awareness of the social - as opposed to purely epistemic - function of belief formation. Finally, we review research on continuities between religious and delusional cognition, which reveals that religious content is quite common in delusions and which provides tentative evidence for a positive relationship between religious belief and delusion-like belief in the general population.