Do deficits in subjective stress recovery predict subsequent stress sensitivity and symptoms in schizophrenia spectrum disorders?

High levels of stress play a crucial role in the development of psychotic symptoms, such as paranoia, and may stem in part from recovery deficits after stress exposure. However, it remains unclear whether deficient recovery causes a build-up of heightened stress levels that increases stress sensitivity and symptoms when exposed to another stressor. To test this, we investigated the effect of subjective stress recovery on the response to a subsequent stressor and paranoia. We applied two consecutive runs of the same combined physical and cognitive stressor separated by a recovery phase of 60 min in individuals with schizophrenia spectrum disorders (n = 49). We repeatedly assessed self-reported stress, negative affect, heart rate, heart rate variability, salivary cortisol, and paranoia. Recovery of self-reported stress was defined as the geometric mean of the percentage changes of self-reported stress during recovery after the first stressor, and was regressed on the response to the second stressor controlling for self-reported stress during the first stressor. Lower subjective stress recovery predicted higher levels of self-reported stress, negative affect, and paranoia in response to the second stressor. The subjective stress recovery was not predictive of the physiological stress response (heart rate, heart rate variability, or salivary cortisol). Taken together, the findings indicate that recovery deficits could contribute to high levels of self-reported stress, negative affect, and paranoia in schizophrenia spectrum disorders and that the improvement of stress recovery could be a promising approach for interventions.

Testing the combination of Feeling Safe and peer counselling against formulation-based cognitive behaviour therapy to promote psychological wellbeing in people with persecutory delusions: study protocol for a randomized controlled trial (the Feeling Safe-NL Trial)

BACKGROUND

Persecutory delusions are strong threat beliefs about others' negative intentions. They can have a major impact on patients' day-to-day life. The Feeling Safe Programme is a new translational cognitive-behaviour therapy that helps patients modify threat beliefs and relearn safety by targeting key psychological causal factors. A different intervention approach, with growing international interest, is peer counselling to facilitate personal recovery. Combining these two approaches is a potential avenue to maximize patient outcomes. This combination of two different treatments will be tested as the Feeling Safe-NL Programme, which aims to promote psychological wellbeing. We will test whether Feeling Safe-NL is more effective and more cost-effective in improving mental wellbeing and reducing persecutory delusions than the current guideline intervention of formulation-based CBT for psychosis (CBTp).

METHODS

A single-blind parallel-group randomized controlled trial for 190 out-patients who experience persecutory delusions and low mental wellbeing. Patients will be randomized (1:1) to Feeling Safe-NL (Feeling Safe and peer counselling) or to formulation-based CBTp, both provided over a period of 6 months. Participants in both conditions are offered the possibility to self-monitor their recovery process. Blinded assessments will be conducted at 0, 6 (post-treatment), 12, and 18 months. The primary outcome is mental wellbeing. The overall effect over time (baseline to 18-month follow-up) and the effects at each timepoint will be determined. Secondary outcomes include the severity of the persecutory delusion, general paranoid ideation, patient-chosen therapy outcomes, and activity. Service use data and quality of life data will be collected for the health-economic evaluation.

DISCUSSION

The Feeling Safe-NL Trial is the first to evaluate a treatment for people with persecutory delusions, while using mental wellbeing as the primary outcome. It will also provide the first evaluation of the combination of a peer counselling intervention and a CBT-based program for recovery from persecutory delusions.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN25766661 (retrospectively registered 7 July 2022).

Sleep and psychotic symptoms: An actigraphy and diary study with young adults with low and elevated psychosis proneness

Experimental research has shown that poor sleep triggers psychotic experiences, even in healthy participants. This warrants an in-depth investigation of this mechanism in a naturalistic environment, an exploration of which particular aspects of poor sleep trigger psychotic symptoms, and a test for reverse effects of symptoms on sleep. For this purpose, we conducted a 14-day ambulatory assessment study with 82 young adults (age: M = 21.24 years, SD = 1.54; 64.6% female), half of which were characterized by elevated psychosis proneness. Objective sleep parameters (actigraphically-measured sleep time, wake after sleep onset, sleep efficiency), self-reported sleep parameters (feeling rested, dream recall, dream valence), and psychotic symptoms (paranoid symptoms, hallucinatory experiences) were assessed once per day. Using multilevel regressions (928 data points), we found that shorter sleep time and negative dream valence predicted paranoid symptoms, whereas feeling less rested and dream recall predicted hallucinatory experiences. In participants with elevated psychosis proneness, associations with the aforementioned sleep parameters were increased for hallucinatory experiences but not for paranoid symptoms. Finally, we found bidirectional associations between poor sleep and paranoid symptoms but only unidirectional associations between poor sleep and hallucinatory experiences. The findings corroborate the relevance of sleep disturbance as a predictor of psychotic experiences. Future studies should further investigate the potential of sleep interventions to prevent psychotic symptoms and disorders.

Suicidal ideation and behaviour in patients with persecutory delusions: Prevalence, symptom associations, and psychological correlates

BACKGROUND

To determine the prevalence of suicidal ideation and behaviour - and their correlates - in patients with persecutory delusions.

METHODS

110 patients with persecutory delusions in the context of non-affective psychosis were assessed for suicidal thoughts and behaviours over the past month. Symptom and psychological assessments were also completed.

RESULTS

The severity of suicidal ideation was: no suicidal ideation (n = 26, 23.6%); wish to be dead (n = 21, 19.1%); nonspecific active suicidal thoughts (n = 14, 12.7%); suicidal thoughts with methods but no intent (n = 29, 26.4%); suicidal thoughts with intent but no specific plan (n = 13, 11.8%); and suicidal intent with plan (n = 7, 6.4%). In the past month, five patients (4.5%) had made an actual, interrupted, or aborted suicide attempt. The severity of suicidal ideation was associated with higher levels of depression, paranoia, hallucinations, anger, insomnia, negative beliefs about the self and others, pessimism, worry, and delusion safety-seeking behaviours and lower levels of psychological well-being and reward responsiveness. Severity of ideation was not associated with cannabis or alcohol use, working memory, pain, or meaningful activity levels.

CONCLUSIONS

Patients with persecutory delusions are typically in a severe state of psychological stress, and at risk of suicide, as indicated by very high levels of suicidal ideation. This exploratory study also identifies correlates of suicidal ideation that could be investigated in causal research designs.

Persecutory delusions: effects of Cognitive Bias Modification for Interpretation and the Maudsley Review Training Programme on social anxiety, jumping to conclusions, belief inflexibility and paranoia

BACKGROUND AND OBJECTIVES

The Threat Anticipation Model (Freeman, 2007) implicates social anxiety, jumping to conclusions (JTC) and belief inflexibility in persecutory delusions. We investigated whether Cognitive Bias Modification for Interpretation (CBM-I; Turner et al., 2011) improves social anxiety by targeting negative interpretation bias of ambiguous social information. We determined whether the Maudsley Review Training Programme (MRTP; Waller et al., 2011) improves JTC, belief inflexibility and paranoia. We also explored effects of CBM-I on JTC/belief inflexibility and paranoia, as well as the MRTP on social anxiety.

METHODS

Twelve participants from Early Intervention and Recovery Services in East Anglia completed measures of social anxiety, paranoia, JTC and belief inflexibility. A concurrent multiple baseline case series design was used.

RESULTS

Three of twelve participants improved in social anxiety following CBM-I, paranoia improved in 6/12 cases. CBM-I had no effect on JTC/belief inflexibility. The MRTP improved JTC and/or belief inflexibility in 9/12 cases, while improving paranoia for 6/12 individuals. The MRTP improved social anxiety in one case.

LIMITATIONS

The small sample size and large effects necessary for single case series designs limit the generality of findings. These are discussed in more detail.

CONCLUSIONS

This study suggests that whilst both CBM-I and the MRTP may have a positive impact on paranoia and social anxiety, the effects on JTC/belief inflexibility are largely specific to the MRTP. Relationships between social anxiety, JTC, belief inflexibility and paranoia existed in 10/12 individuals, supporting the Threat Anticipation Model.

Examining reasoning biases in schizophrenia using a modified "Jumping to Conclusions" probabilistic reasoning task

Although the Jumping To Conclusion (JTC) bias has been extensively studied in relation to schizophrenia and persecutory delusions, the relationship between JTC and other reasoning biases implicated in delusional ideation is not fully understood. We modified the traditional JTC task to assess co-occurrence of reasoning biases in decision making. Forty-six patients with schizophrenia and 46 healthy controls completed two versions [neutral colored beads and salient comments] of the modified task. We replicated previous findings indicating that patients showed a greater JTC bias, and in both groups, the JTC bias was more pronounced for the salient task. However, we observed a significant effect for non-Bayesian judgments, indicating that patients showed greater difficulty in probabilistic reasoning. When controlling for probabilistic reasoning ability, the observed JTC bias effects were diminished. Our findings that faulty probability assessment accounts for the JTC bias indicates that the traditional JTC bias task may not represent an inherent hasty decision-making bias, but rather an inability to fully understand and execute the stated goals of the task. These results call into question the current understanding of the JTC bias and the independence of this bias apart from the cognitive demands of the task.

Schematic beliefs and problem solving performance predict depression in people experiencing persecutory delusions

Depression occurring alongside psychosis is an important treatment target, both in its own right and as a potential maintenance factor for positive psychotic symptoms. The present paper reports a prospective longitudinal analysis of depression and its predictors over six months in a group of 60 participants experiencing persecutory delusions. We hypothesised that negative schematic beliefs about the self and problem solving difficulties would predict the persistence of depression over time. The results showed, as hypothesised, that more negative schematic beliefs about the self and poorer problem solving predicted higher depression scores six months later, beyond what could be predicted by baseline depression scores. These findings support a proposed role for schematic beliefs and problem solving difficulties in the perpetuation of depression occurring alongside psychosis, as has been substantiated for major depressive disorder. Interventionist research is warranted to confirm causal effects.

Sleeping Paranoia Away? An Actigraphy and Experience-Sampling Study with Adolescents

Paranoid symptoms co-occur with distress and poor functioning and constitute a risk for psychosis and other mental disorders. Poor sleep is known to be associated with paranoid symptoms, but the direction of the effect and the mediating factors have not been studied thoroughly. In an experience-sampling study, 61 adolescents wore an actigraph over eight nights and also rated their sleep, symptoms of paranoia, and potentially mediating factors. Shorter sleep time and more dreaming predicted paranoid symptoms in multilevel regression models. Paranoid symptoms did not significantly predict sleep parameters. Positive and negative affect partially mediated the effect of sleep time on paranoid symptoms. The effects were small, but encourage further research that might then be used to improve the prevention of paranoid symptoms.

Responsibility beliefs and persecutory delusions

Recent research implicates cognitive processes traditionally linked to anxiety disorders in the maintenance of paranoia. Responsibility beliefs have traditionally been associated with OCD, and recent research suggests they may be transdiagnostic. The present study reports the first data on responsibility beliefs in individuals with persecutory delusions. 30 people with persecutory delusions completed measures of psychotic symptoms and responsibility beliefs. Participants were also asked to identify who they held responsible for their persecution. Quantitative data on responsibility beliefs were compared with 29 matched non-clinical control participants, and with published data from patients with OCD and anxiety disorders. People with persecutory delusions identified a number of different entities responsible for harm. The persecutory delusions group had higher responsibility beliefs than those with OCD, anxiety disorders and nonclinical controls. The results suggest that responsibility beliefs are a facet of the phenomenology of persecutory beliefs. Cognitive-behavioural therapy for psychosis might usefully draw from OCD interventions and focus on responsibility beliefs, perhaps especially in Bad Me paranoia.

Testing the Trower and Chadwick model of paranoia: Is 'poor-me' and 'bad-me' paranoia acting as a defence?

The study tested the predicted differences in phenomenology (self-esteem and depression) and insecurity of the subgroups of paranoia proposed by the Trower and Chadwick (1995) model of paranoia. Thirty-two inpatients experiencing persecutory delusions were assigned to either the poor me or bad me paranoid group. Questionnaire assessment of depression and self-esteem were conducted. A Dot Probe task measured detection latency (reaction time) to poor me words, bad me words and neutral words. The poor me and bad me groups displayed the predicted phenomenological differences. The dot probe task did not support the predicted insecurities of the Trower and Chadwick model, but unexpected significant results for the poor me subgroup may offer support for an alternative explanation of paranoia as an unstable phenomenon.

Cognitive Bias Modification for paranoia (CBM-pa): study protocol for a randomised controlled trial

BACKGROUND

Persecutory delusions are the most common type of delusions in psychosis and present in around 10-15% of the general population. Persecutory delusions are thought to be sustained by biased cognitive and emotional processes. Recent advances favour targeted interventions, focussing on specific symptoms or mechanisms. Our aim is to test the clinical feasibility of a novel psychological intervention, which manipulates biased interpretations toward more adaptive processing, in order to reduce paranoia in patients.

METHODS

The 'Cognitive Bias Modification for paranoia' (CBM-pa) study is a feasibility, double-blind, randomised controlled trial (RCT) for 60 stabilised outpatients with persistent, distressing paranoid symptoms. Patients will be randomised at a 50:50 ratio, to computerised CBM-pa or a text-reading control intervention, receiving one 40-min session per week, for 6 weeks. CBM-pa involves participants reading stories on a computer screen, completing missing words and answering questions about each story in a way that encourages more helpful beliefs about themselves and others. Treatment as Usual will continue for patients in both groups. Patients will be assessed by a researcher blind to allocation, at baseline, each interim session, post treatment and 1- and 3-month follow-up post treatment. The primary outcome is the feasibility parameters (trial design, recruitment rate and acceptability) of the intervention. The secondary outcomes are clinical symptoms (including severity of paranoia) as assessed by a clinical psychologist, and 'on-line' measurement of interpretation bias and stress/distress. The trial is funded by the NHS National Institute for Health Research.

DISCUSSION

This pilot study will test whether CBM-pa has the potential to be a cost-effective, accessible and flexible treatment. If the trial proves feasible and demonstrates preliminary evidence of efficacy, a fully powered RCT will be warranted.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN: 90749868 . Retrospectively registered on 12 May 2016.

An experimental investigation into the role of ruminative and mindful self-focus in non-clinical paranoia

BACKGROUND & OBJECTIVES

Ruminative self-focus is a maladaptive form of emotional processing and is linked to distress, whereas mindful self-focus is adaptive and linked to low distress. However, the effects of these different modes of self-focus have not yet been examined in symptoms associated with psychotic disorders, such as paranoid ideation. This study aimed to explore whether inducing ruminative self-focus maintains paranoid ideation whilst inducing mindful self-focus reduces paranoid ideation.

METHOD

Thirty-two non-clinical participants engaged in a paranoia induction prime and then took part in an eight-minute ruminative self-focus induction and an eight-minute mindful self-focus induction.

RESULTS

Following an induction of paranoia, mindful self-focus significantly decreased levels of paranoia, whereas ruminative self-focus had no significant impact on levels of paranoia, and therefore was interpreted as having maintained paranoia.

LIMITATIONS

The study used non clinical participants and the level of paranoid ideation experienced was fairly mild, which limits generalisation to clinical levels of distress. Additionally, the mechanism by which rumination and mindful self-focus have their effects was not examined.

CONCLUSIONS

The results add to the growing body of evidence that there are two distinct modes of self-focus that have differential effects on emotional processing. These findings also demonstrate the potential benefit of interventions targeting rumination in paranoid ideation with mindful self-focus.

The Beliefs about Paranoia Scale: Confirmatory factor analysis and tests of a metacognitive model of paranoia in a clinical sample

This study aimed to confirm the factor structure of the Beliefs about Paranoia Scale (BaPS), a self-report measure to assess metacognitive beliefs about paranoia, and to test hypotheses of a metacognitive model. We hypothesised that positive and negative beliefs about paranoia would be associated with severity of suspiciousness, and that the co-occurrence of positive and negative beliefs would be associated with increased suspiciousness. A total of 335 patients meeting criteria for a schizophrenia spectrum disorder completed the BaPS, the Positive and Negative Syndromes Scale (PANSS), and the Psychotic Symptom Rating Scales (PSYRATS). Confirmatory factor analysis verified that the three BaPS subscales (negative beliefs about paranoia, paranoia as a survival strategy, and normalizing beliefs) were an adequate fit of the data. Ordinal regression showed that positive beliefs about paranoia as a survival strategy and negative beliefs were both associated with severity of suspiciousness. This was the first study to show that the co-occurrence of positive and negative beliefs was associated with increased suspiciousness. All hypotheses were confirmed, suggesting that a metacognitive approach has utility for the conceptualization of paranoia. Clinical implications suggest a role for metacognitive therapy, including strategies such as detached mindfulness and worry postponement.

Delusions in first-episode psychosis: Principal component analysis of twelve types of delusions and demographic and clinical correlates of resulting domains

Although delusions represent one of the core symptoms of psychotic disorders, it is remarkable that few studies have investigated distinct delusional themes. We analyzed data from a large sample of first-episode psychosis patients (n=245) to understand relations between delusion types and demographic and clinical correlates. First, we conducted a principal component analysis (PCA) of the 12 delusion items within the Scale for the Assessment of Positive Symptoms (SAPS). Then, using the domains derived via PCA, we tested a priori hypotheses and answered exploratory research questions related to delusional content. PCA revealed five distinct components: Delusions of Influence, Grandiose/Religious Delusions, Paranoid Delusions, Negative Affect Delusions (jealousy, and sin or guilt), and Somatic Delusions. The most prevalent type of delusion was Paranoid Delusions, and such delusions were more common at older ages at onset of psychosis. The level of Delusions of Influence was correlated with the severity of hallucinations and negative symptoms. We ascertained a general relationship between different childhood adversities and delusional themes, and a specific relationship between Somatic Delusions and childhood neglect. Moreover, we found higher scores on Delusions of Influence and Negative Affect Delusions among cannabis and stimulant users. Our results support considering delusions as varied experiences with varying prevalences and correlates.

Understanding the paranoid psychosis of James: Use of the repertory grid technique for case conceptualization

In this paper we illustrate the potential of the repertory grid technique as an instrument for case formulation and understanding of the personal perception and meanings of people with a diagnosis of psychotic disorders. For this purpose, the case of James is presented: A young man diagnosed with schizophrenia and personality disorder, with severe persecutory delusions and other positive symptoms that have not responded to antipsychotic medication, as well with depressive symptomatology. His case was selected because of the way his symptoms are reflected in his personal perception of self and others, including his main persecutory figure, in the different measures that result from the analysis of his repertory grid. Some key clinical hypotheses and possible targets for therapy are discussed.

Automatic attentional orienting to other people's gaze in schizophrenia

Explicit tests of social cognition have revealed pervasive deficits in schizophrenia. Less is known of automatic social cognition in schizophrenia. We used a spatial orienting task to investigate automatic shifts of attention cued by another person's eye gaze in 29 patients and 28 controls. Central photographic images of a face with eyes shifted left or right, or looking straight ahead, preceded targets that appeared left or right of the cue. To examine automatic effects, cue direction was non-predictive of target location. Cue-target intervals were 100, 300, and 800 ms. In non-social control trials, arrows replaced eye-gaze cues. Both groups showed automatic attentional orienting indexed by faster reaction times (RTs) when arrows were congruent with target location across all cue-target intervals. Similar congruency effects were seen for eye-shift cues at 300 and 800 ms intervals, but patients showed significantly larger congruency effects at 800 ms, which were driven by delayed responses to incongruent target locations. At short 100-ms cue-target intervals, neither group showed faster RTs for congruent than for incongruent eye-shift cues, but patients were significantly slower to detect targets after direct-gaze cues. These findings conflict with previous studies using schematic line drawings of eye-shifts that have found automatic attentional orienting to be reduced in schizophrenia. Instead, our data indicate that patients display abnormalities in responding to gaze direction at various stages of gaze processing-reflected by a stronger preferential capture of attention by another person's direct eye contact at initial stages of gaze processing and difficulties disengaging from a gazed-at location once shared attention is established.

Early relationships and paranoia: Qualitative investigation of childhood experiences associated with the development of persecutory delusions

Research suggests a link between Persecutory Delusions (PDs) and early interpersonal difficulties. However, little research has explored the first-hand experience of navigating such adversities in those who later developed PDs. The current study reports on a qualitative investigation of the early interpersonal experiences and challenges faced by a sample of individuals who have recovered from PDs, using a semi-structured interview. A sample of seven individuals who have previously experienced PDs were recruited from two National Health Services (NHS) and an Early Intervention Psychosis service in England. Using an Interpretative Phenomenological Analytic (IPA) approach, the analysis identified three main themes (early experiences, impact of early experiences, coping with adversity). Early experiences captured early inconsistent and problematic relationships in childhood, and experiences of victimization. Exploring the impact of these early events revealed important roles for the participants' inconsistent sense of self, their negative perception of others, and their disturbed social functioning and substance use. Coping with adversity revealed distinct forms of avoidant and proactive coping. The findings are consistent with models of PDs that emphasise the impact of early interpersonal experiences, and offer support for attachment and cognitive factors.

The role of mental imagery in non-clinical paranoia

BACKGROUND & OBJECTIVES

Cognitive models of paranoia incorporate many of the processes implicated in the maintenance of anxiety disorders. Despite this, the role of mental imagery in paranoia remains under-researched. The current study examined the impact of a self-imagery manipulation in people with high non-clinical paranoia.

METHODS

We used a mixed design with one between-subjects variable (type of self-imagery) and one within-subjects variable (time--pre and post imagery manipulation). Thirty participants with high trait paranoia were allocated alternately to a positive or negative self-imagery condition. Scripts were used to elicit positive and negative self-imagery. All participants completed self-report state measures of paranoia, mood, self-esteem and self-compassion.

RESULTS

Group by time interaction effects were found for each of the dependent variables. Positive imagery led to less state paranoia, anxiety and negative affect, and more positive affect, self-esteem and self-compassion, compared with the negative imagery group.

LIMITATIONS

This was a non-blind study, limited by allocation method and a brief time-frame which did not allow us to assess longevity of effects. We recruited a relatively small and predominantly female sample of people with high non-clinical paranoia. The study did not include a neutral control condition, a low paranoia comparison group, or a manipulation check following the imagery task.

CONCLUSIONS

Self-imagery manipulations may affect paranoia, mood and self-beliefs. If the findings are replicated with clinical groups, and maintained over a longer period, this would suggest that imagery-based interventions targeting persecutory delusions might be usefully examined.

Recall of threat material is modulated by self or other referencing in people with high or low levels of non-clinical paranoia

BACKGROUND AND OBJECTIVES

Biased processing of negatively valenced, and particularly threat-related material plays an important role in the development of paranoid thinking. This has been demonstrated by superior memory for threat-related information in patients with persecutory delusions and in non-clinical paranoia-prone participants. This study examined how emotional material was recalled having been encoded in relation to one self or to another person, in people high or low in paranoid ideation. It was predicted that people high in paranoia would recall more threat related material about others than people low in paranoia owing to being particularly alert to threats from other people.

METHODS

Participants who reported high (N = 30) or low (N = 30) levels of sub-clinical paranoid thinking were presented with a series of threat-related and positive words and were asked to process them in terms of the self, or in terms of a fictional character.

RESULTS

As predicted, when words were processed in terms of another person, the high paranoia group recalled more threat-related words than positive words, but when words had been processed in terms of the self, recall of threat-related and positive words did not differ. In contrast, there was no interaction between word-valence and referent in the low paranoia group.

LIMITATIONS

These findings are drawn from an analogue sample. Replication in a sample of clinical participants who report persecutory delusions is required.

CONCLUSIONS

People high in sub-clinical paranoid ideation recalled threat preferentially in relation to other people. Such information processing biases may help understand the development and maintenance of persecutory beliefs.

Insight in paranoia: The role of experiential avoidance and internalized stigma

Evidence suggests that insight in psychosis has been related to treatment adherence, recovery and good prognosis, but also to depression, low self-esteem, and diminished quality of life. Thus, insight might not be advantageous under all circumstances. Internalized-stigma (i.e. self-acceptance of stigmatizing images of illness) and experiential avoidance (i.e. unwillingness to experience negative private events) have been proposed as moderating variables between insight, and psychological health variables and/or distress. We investigated the patterns of association of insight with satisfaction with life, self-esteem, depression, anxiety and psychotic psychopathology as moderated by self-stigmatizing beliefs and experiential avoidance, in a sample of 47 participants with persecutory beliefs and diagnosed with schizophrenia or other psychotic disorder. Moderation analyses confirm the importance of internalized-stigma and experiential avoidance. The presence of insight was associated with more depression when there were high levels of self-stigma. Whereas, the absence of insight was associated with a greater life satisfaction when there were high levels of experiential avoidance. To summarize, our results help understand the complex relationship between insight, psychological health variables and emotional distress, pointing to a differential pattern of moderation for negative and positive outcomes. We discuss the implications of these results for research and treatment of paranoia.

Prefrontal activity measured by functional near infrared spectroscopy during probabilistic inference in subjects with persecutory delusions

Jumping to conclusions (JTC) is a probabilistic reasoning bias and is thought to contribute to delusion formation. Neurobiological correlates of the JTC bias are not known. We aimed to examine the rostral prefrontal cortex (rPFC) activity with functional near ınfrared spectroscopy during a modified version of the Beads in a Jar Task (BIJT) in subjects with persecutory delusions (N=25). In BIJT participants are presented beads either drawn from one of the two jars with opposite probability ratios (PRs) of colored beads and are required to decide from which jar beads are being drawn. We administered the BIJT with 90/10 and 55/45 PRs. Compared to healthy controls (N=20), patients reached a decision earlier in both conditions. While the medial rPFC regions were more active in the 90/10 condition in controls compared to patients, lateral rPFC activation was higher in the 55/45 condition in patients than controls. Only in the control group, there was a marked decline in the lateral rPFC activation in the 55/45 condition compared to the 90/10 condition. The activity in the lateral rPFC was negatively correlated with the amount of beads drawn in healthy controls but not in subjects with persecutory delusions. Our results suggest that during the BIJT, rPFC does not function as a single unit and rather consists of functional subunits that are organized differently in patients and controls. The failure to deactivate the lateral rPFC may be associated with earlier decisions in subjects with persecutory delusions.