Vaughan Bell's research while affiliated with South London and Maudsley NHS Foundation Trust and other places

Publications (140)

Article
Recent work in social cognition has moved beyond a focus on how people process social rewards to examine how healthy people represent other agents and how this is altered in psychiatric disorders. However, formal modelling of social representation has not kept pace with these changes, impeding our understanding of how core aspects of social cogniti...
Preprint
Full-text available
Background: The co-occurrence of stroke and psychosis is a serious neuropsychiatric condition, but little is known about the course of this comorbidity. Aims: To estimate longitudinal associations between stroke and psychosis over 10 years. Methods: A 10-year population-based study using data from the English Longitudinal Study of Ageing. A structu...
Preprint
Recent work in social cognition has moved beyond a focus on how people process social reward to examine how healthy people represent other agents and how this is altered in psychiatric disorder. However, formal modelling of social representation has not kept pace with these changes, impeding our understanding of how core aspects of social cognition...
Article
Full-text available
The relationship between sleep disorder and psychotic experiences in preadolescence has not been extensively studied despite the potential for intervention. The current study addressed this relationship using the Adolescent Brain and Cognitive Development (ABCD) cohort, which provided baseline data from 11,830 10- to 11-year-old; for 4910 of these,...
Article
Full-text available
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 t...
Article
Full-text available
Alterations to striatal reward pathways have been identified in individuals with psychosis. They are hypothesised to be a key mechanism that generate psychotic symptoms through the production of aberrant attribution of motivational salience and are proposed to result from accumulated childhood adversity and genetic risk, making the striatal system...
Article
Full-text available
Hallucinated voices cause high levels of distress and disability. Current theories suggest that insight-related beliefs, about internal or external origin, perceived source location, and appraisals of controllability are important in mediating the impact of these experiences but previous findings have been mixed. We report two open code and open da...
Preprint
Full-text available
Background: Both stroke and psychosis are independently associated with high levels of disability. However, psychosis in the context of stroke has received remarkably little interest from clinicians and researchers. To date there are currently no population studies on their joint prevalence and association. Methods: We estimated the prevalence of i...
Article
The heightened belief that others intend to harm you (paranoia) is often accompanied by social withdrawal, avoidance and isolation. We investigated whether paranoia is related to betrayal aversion: the tendency to avoid potential harm caused by other people over and above an equivalent harm caused by a non-social mechanism. Across three large-N (Nt...
Article
Full-text available
Objective: Paranoia is known to vary with levels of coalitional threat and safety present in the social environment. However, it remains underexplored whether threat and safety are differentially associated with paranoia, if these relationships vary with the source of threat and safety, and whether such effects hold across the continuum of severit...
Article
Social learning underpins our species's extraordinary success. Learning through observation has been investigated in several species, but learning from advice—where information is intentionally broadcast—is less understood. We used a pre-registered, online experiment ( n = 1492) combined with computational modelling to examine learning through obse...
Article
Full-text available
Hallucinatory experiences (HEs) can be pronounced in psychosis, but similar experiences also occur in nonclinical populations. Cognitive mechanisms hypothesized to underpin HEs include dysfunctional source monitoring, heightened signal detection, and impaired attentional processes. Using data from an international multisite study on non-clinical pa...
Article
Full-text available
Background: The effect of the Colombian armed conflict on the mental health of adolescents is still poorly understood. Aims: Given social interventions are most likely to inform policy, we tested whether two potential intervention targets, family functioning and social capital, were associated with mental health in Colombian adolescents, and wheth...
Preprint
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 a...
Article
Full-text available
Objectives: Psychosis has a strong social component and often involves the experience of being affected by 'illusory social agents'. However, this experience remains under-characterized, particularly for social agents in delusions and non-vocal hallucinations. One useful approach is a form of computational linguistics called corpus linguistics tha...
Article
Full-text available
The burden of large and rare copy number genetic variants (CNVs) as well as certain specific CNVs increase the risk of developing schizophrenia. Several cognitive measures are purported schizophrenia endophenotypes and may represent an intermediate point between genetics and the illness. This paper investigates the influence of CNVs on cognition. W...
Preprint
Social interactions can be beneficial by allowing individuals to learn socially about their environment or collaborate to achieve outcomes that are otherwise unattainable. Social interactions can also be costly if individuals risk being exploited, attacked, or otherwise harmed as a result of the encounter. Individuals are expected to refrain from s...
Preprint
Full-text available
Background: The effect of the Colombian armed conflict on the mental health of adolescents is still poorly understood. Given social interventions are most likely to inform policy, we tested whether two potential intervention targets, family functioning and social capital, were associated with mental health in Colombian adolescents, and whether this...
Article
Full-text available
Hallucinatory experiences can occur in both clinical and nonclinical groups. However, in previous studies of the general population, investigations of the cognitive mechanisms underlying hallucinatory experiences have yielded inconsistent results. We ran a large-scale preregistered multisite study, in which general-population participants ( N = 1,3...
Preprint
Full-text available
Alterations to striatal reward pathways have been identified in individuals with psychosis. They are hypothesised to be a key mechanism that generates psychotic symptoms through the production of aberrant attribution of motivational salience and are proposed to result from accumulated childhood adversity in combination with genetic risk, making the...
Preprint
Social learning underpins our species’ extraordinary success. Learning through observation has been investigated in several species but learning from advice – where information is intentionally broadcast – is less understood. We used a pre-registered, online experiment (N=1492) combined with computational modelling to examine learning through obser...
Preprint
Believing that others intend to harm you (paranoia) is often accompanied by social withdrawal, avoidance and isolation. We investigated whether paranoia is related to betrayal aversion: the tendency to avoid potential harm caused by other people over and above an equivalent harm caused by a non-social mechanism. Across three large-N (Ntotal=2433) p...
Preprint
Cognitive mechanisms hypothesized to underlie hallucinatory experiences (HEs) include dysfunctional source monitoring, heightened signal detection, or impaired attentional processes. HEs can be very pronounced in psychosis, but similar experiences also occur in nonclinical populations. Using data from an international multisite study on nonclinical...
Preprint
Full-text available
Aims: Psychosis has a strong social component and often involves the experience of being affected by 'illusory social agents'. However, this experience remains under-characterised, particularly for social agents in delusions and non-vocal hallucinations. One useful approach is a form of computational linguistics called corpus linguistics that studi...
Preprint
Full-text available
Sleep problems have been reliably associated with psychotic experiences in adults and have been suggested as target for intervention. However, the relationship between sleep disorder and psychotic experiences in children has not been extensively studied despite the potential for guiding intervention. The Adolescent Brain Cognitive Development (ABCD...
Article
Full-text available
Purpose The SARS-CoV-2 / COVID-19 pandemic has raised concerns about the potential mental health impact on frontline clinical staff. However, given that poor mental health is common in acute medical staff, we aimed to estimate the additional burden of work involving high exposure to infected patients. Methods We report a rapid review, meta-analysi...
Article
Full-text available
Paranoia is the exaggerated belief that harm will occur and is intended by others. Although commonly framed in terms of attributing malicious intent to others, recent work has explored how paranoia also affects social decision-making, using economic games. Previous work found that paranoia is associated with decreased cooperation and increased puni...
Article
Full-text available
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,...
Article
Full-text available
Sharing privately held information, for example, one’s confidence in the likelihood of future events, can greatly help others make better decisions as well as promoting one’s reputation and social influence. Differences in metacognition on the one hand, and difficulties in social functioning and social cognition on the other, have been reported in...
Article
Full-text available
Current computational models suggest that paranoia may be explained by stronger higher-order beliefs about others and increased sensitivity to environments. However, it is unclear whether this applies to social contexts, and whether it is specific to harmful intent attributions, the live expression of paranoia. We sought to fill this gap this by fi...
Article
Full-text available
Background Depression and anxiety symptoms are common among university students, but many do not receive treatment. This is often because of lack of availability, reluctance to seek help, and not meeting the diagnostic criteria required to access services. Internet-based interventions, including smartphone apps, can overcome these issues. However,...
Article
Full-text available
Altered dopamine transmission is thought to influence the formation of persecutory delusions. However, despite extensive evidence from clinical studies there is little experimental evidence on how modulating the dopamine system changes social attributions related to paranoia, and the salience of beliefs more generally. Twenty seven healthy male par...
Preprint
Sharing privately held information, for example one’s confidence in the likelihood of future events, can greatly help others make better decisions as well as promoting one’s reputation and social influence. Differences in metacognition on the one hand, and difficulties in social functioning and social cognition on the other, have been found in schi...
Article
Full-text available
The functional-organic distinction aims to distinguish symptoms, signs, and syndromes that can be explained by diagnosable biological changes, from those that cannot. The distinction is central to clinical practice and is a key organising principle in diagnostic systems. Following a pragmatist approach that examines meaning through use, we examine...
Preprint
Hallucinatory experiences (HEs) can occur in both clinical and non-clinical groups. However, previous studies of the general population that have investigated cognitive mechanisms underlying HEs have yielded inconsistent results. In this study, we ran a large-scale preregistered multi-site study, in which general population participants (N = 1394,...
Article
Full-text available
Background Individuals with psychosis display an attenuated response to reward. However, it has not yet been established whether individuals with psychotic-like experiences (PLEs) also exhibit alterations in reward anticipation. Methods The present study examined whether non-distressing and distressing PLEs were associated with functional activity...
Preprint
Full-text available
The global pandemic of SARS-CoV-2 / COVID-19 has raised concerns about the potential mental health impact on frontline clinical staff. However, given that poor mental health is common in staff working in acute medicine, we aimed to estimate the additional burden of working directly with infected patients during epidemic and pandemic health emergenc...
Preprint
Current computational models suggest that paranoia may be explained by stronger higher-order beliefs about others and increased sensitivity to environments. However, it is unclear whether this applies to social contexts, and whether it is specific to harmful intent attributions, the live expression of paranoia. We sought to fill this gap this by fi...
Article
Following the 2014 Ebola outbreak, South London and Maudsley NHS Foundation Trust (SLAM) were commissioned to provide a ‘culturally appropriate, effective and sustainable’ intervention to address the psychological needs of the Sierra Leonean Ebola Treatment Centre (ETC) staff. The study evaluated the effectiveness of group Cognitive Behavioural The...
Article
Full-text available
The sensitization model suggests that paranoia is explained by over-sensitivity to social threat. However, this has been difficult to test experimentally. We report two preregistered social interaction studies that tested (i) whether paranoia predicted overall attribution and peak attribution of harmful intent and (ii) whether anxiety, interpersona...
Preprint
The functional-organic distinction aims to distinguish symptoms, signs, and syndromes that can be explained by diagnosable biological changes, from those that cannot. The distinction is central to clinical practice and is a key organising principle in diagnostic systems. Following a pragmatist approach that examines meaning through use, we examine...
Article
Full-text available
Developmental trauma is associated with an increased risk of psychosis and predicts poor prognosis. Despite this association, little is known about which treatments work best for survivors of developmental trauma with psychosis. We sought to do the first review, to our knowledge, to investigate treatments for people with psychotic and dissociative...
Preprint
Full-text available
Altered dopamine transmission is thought to influence the formation of persecutory delusions. However, despite extensive evidence from clinical studies there is little experimental evidence on how modulating the dopamine system changes social attributions related to paranoia, and the salience of beliefs more generally. 27 healthy male participants...
Preprint
Full-text available
Paranoia is the belief that harm will occur and is intended by others. Although commonly framed in terms of attributing malicious intent to others, recent work has explored how paranoia also affects social behaviour, using economic games. Previous work found that paranoia is associated with decreased cooperation and increased punishment in the Dict...
Preprint
Due to the traditional conceptualisation 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 i) equivalently irrational beliefs can be induced through adaptive social cognitive processes, refle...
Preprint
The sensitisation model suggests paranoia is explained by over-sensitivity to perceived threat in social environments. However, this has been difficult to test experimentally. We report two pre-registered studies that tested i) the sensitisation model as an explanation of paranoia, and; ii) the role of purported maintaining factors in supporting so...
Article
Full-text available
Current theories argue that hyper-sensitisation of social threat perception is central to paranoia. Affected people often also report misperceptions of group cohesion (conspiracy) but little is known about the cognitive mechanisms underpinning this conspiracy thinking in live interactions. In a pre-registered experimental study, we used a large-sca...
Preprint
BACKGROUND Depression and anxiety symptoms are common among university students, but many do not receive treatment. This is often because of lack of availability, reluctance to seek help, and not meeting the diagnostic criteria required to access services. Internet-based interventions, including smartphone apps, can overcome these issues. However,...
Article
Full-text available
The cognitive processes underlying belief are still obscure. Understanding these processes may lead to more targeted treatment to better address functional impairment, such as occurs with delusions. One way in which this might be accomplished is to understand healthy, everyday beliefs, and how these may relate to characteristics observed in delusio...
Preprint
Full-text available
Hallucinated voices are a common feature of psychosis and can cause high levels of distress and disability. Current theories suggest that insight-related beliefs, about internal or external origin and perceived source location, and appraisals of controllability are important in mediating the personal impact of these experiences but previous finding...
Article
Full-text available
The Cardiff Anomalous Perceptions Scale (CAPS) is a psychometric measure of hallucinatory experience. It has been widely used in English and used in initial studies in Spanish but a full validation study has not yet been published. We report a validation study of the Spanish-language CAPS, conducted in both Spain and Colombia to cover both European...
Article
Full-text available
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...
Article
Full-text available
That trauma can play a significant role in the onset and maintenance of voice-hearing is one of the most striking and important developments in the recent study of psychosis. Yet the finding that trauma increases the risk for hallucination and for psychosis is quite different from the claim that trauma is necessary for either to occur. Trauma is of...
Article
Paranoia is the most common symptom of psychosis but paranoid concerns occur throughout the general population. Here, we argue for an evolutionary approach to paranoia across the spectrum of severity that accounts for its complex social phenomenology — including the perception of conspiracy and selective identification of perceived persecutors — an...
Preprint
Full-text available
The cognitive processes underlying belief are still obscure. Understanding these processes may lead to more targeted treatment to better address functional impairment, such as delusions. One way in which this might be accomplished is to identify the mechanisms of healthy, everyday belief, and how these may relate to characteristics observed in delu...
Preprint
Introduction: Although important to cognitive neuropsychiatry and theories of delusions, Capgras delusion has largely been reported in single case studies. Bell et al. (2017) 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. W...
Preprint
Although paranoia is the most commonly presenting symptom of psychosis, paranoid thoughts occur frequently in the general population and range widely in severity, from mild socio-evaluative concerns to frank delusions about the harmful intentions of others. Furthermore, paranoia commonly appears after a surprisingly diverse range of difficulties in...
Article
Full-text available
The ability to attribute intentions to others is a hallmark of human social cognition but is altered in paranoia. Paranoia is the most common positive symptom of psychosis but is also present to varying degrees in the general population. Epidemiological models suggest that psychosis risk is associated with low social rank and minority status, but t...
Article
Full-text available
Objectives: Adverse psychological outcomes, following stressful experiences in critical care, affect up to 50% of patients. We aimed to develop and test the feasibility of a psychological intervention to reduce acute stress and prevent future morbidity. Design: A mixed-methods intervention development study, using two stages of the UK Medical Re...
Article
Full-text available
Purpose: Bebbington and colleagues' influential study on 'the structure of paranoia in the general population' used data from the British National Psychiatric Morbidity Survey and latent variable analysis methods. Network analysis is a relatively new approach in psychopathology research that considers mental disorders to be emergent phenomena from...
Preprint
Current theories argue that hyper-sensitisation of social threat perception is central to paranoia. Affected people often also report misperceptions of group cohesion (conspiracy) but little is known about how paranoid ideation affects conspiracy thinking in live interactions. In a pre-registered experimental study, we used a large-scale game theor...
Article
Full-text available
Although significant progress has been made in the peace process, Colombia still experiences high levels of ongoing violence and a legacy of more than five decades of armed conflict. Epidemiological studies show markedly raised levels of mental health problems in people affected by the conflict, with internally displaced people being a large and im...
Preprint
Objective: Mindfulness involves a range of cognitive and affective processes. Most research has investigated the 'intended' and beneficial processes. The cognitive-emotional regulatory strategies (CERS) and difficulties encountered during mindfulness practice were investigated in order to establish a questionnaire to evaluate concomitant processes...
Preprint
Fear of others intending harm is central in paranoia but it is unclear to what extent social context alters paranoid attributions, and how this interacts with pre-existing paranoia. We examined social interactions via game theory paradigms across social rank (Experiment 1) and political group affiliation (Experiment 2) as a function of pre-existing...
Article
A preregistered systematic review of poststroke psychosis examining clinical characteristics, prevalence, diagnostic procedures, lesion location, treatments, risk factors and outcome. Neuropsychiatric outcomes following stroke are common and severely impact quality of life. No previous reviews have focused on poststroke psychosis despite clear clin...
Article
Full-text available
Current definitions of paranoia include two key components: unfounded ideas of harm and the idea that the harm is intended by others. However, attributions of harmful intent have been poorly studied and mainly using artificial scenarios rather than participation in genuine social interactions where genuine resources are at stake. Using a large non-...
Preprint
Aims and objectives: A pre-registered systematic review of post-stroke psychosis examining clinical characteristics, prevalence, diagnostic procedures, lesion location, treatments, risk factors, and long-term outcomes.Background: Neuropsychiatric outcomes following stroke are common and severely impact quality of life. Previous reviews have focused...
Article
Full-text available
Background Paranoia involves thoughts and beliefs about the harmful intent of others but the social consequences have been much less studied. We investigated whether paranoia predicts maladaptive social behaviour in terms of cooperative and punitive behaviour using experimental game theory paradigms, and examined whether reduced cooperation is best...
Poster
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Poster presented at ESRI 2017 to illustrate the validation of the SenPQ and it’s possible implications for future research.
Article
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Background Capgras delusion is scientifically important but most commonly reported as single case studies. Studies analysing large clinical records databases focus on common disorders but none have investigated rare syndromes. Aims Identify cases of Capgras delusion and associated psychopathology, demographics, cognitive function and neuropatholog...
Article
Full-text available
- Background: The experience of 'sensed presence' a feeling or sense that another entity, individual or being is present despite no clear sensory or perceptual evidence?is known to occur in the general population, appears more frequently in religious or spiritual contexts, and seems to be prominent in certain psychiatric or neurological conditions...
Article
Full-text available
The positive symptoms of psychosis largely involve the experience of illusory social actors, and yet our current measures of social cognition, at best, only weakly predict their presence. We review evidence to suggest that the range of current approaches in social cognition is not sufficient to explain the fundamentally social nature of these exper...
Article
Full-text available
This paper has two goals. The first is to determine the factor structure of the proneness to hallucination in a sample of the Colombian population using the Launay-Slade Hallucination Scale Revised (LSHS-R). The second goal is to compare the results of the non-clinical population with the results of a group of patients diagnosed with schizophrenia....
Article
The psychosis continuum: Psychometric evidence. This paper has two goals. The first is to determine the factor structure of the proneness to hallucination in a sample of the Colombian population using the Launay-Slade Hallucination Scale Revised (LSHS-R). The second goal is to compare the results of the non-clinical population with the results of a...