Odd Beliefs Research Articles

Positive and negative schizotypy personality traits are lower in individuals on ketogenic diet in a non-clinical sample

Schizotypal personality comprises traits such as odd beliefs, perceptual abnormalities, and social difficulties; these traits are distributed throughout the general population. While not meeting the clinical threshold for schizophrenia or schizotypal personality disorder, schizotypal personality traits still provide insights for understanding early clinical risk factors. Ketogenic diet reportedly reduces psychotic symptoms in preclinical and clinical studies. Therefore, we investigated whether ketogenic diet is associated with lower schizotypal traits in the general population. Participants following a ketogenic or other diet were recruited using opportunity sampling. Individuals completed a survey investigating general demographic, socioeconomic, health, diet and lifestyle questions, followed by the Schizotypal Personality Questionnaire – Brief Revised version (SPQ-BR). We found that individuals following a ketogenic diet (n = 118) had lower ideas of reference, magical thinking, suspiciousness, unusual perceptions, constricted affect, social anxiety scores, cognitive (positive) perceptual scores, interpersonal (negative) scores and total SPQ-BR compared to individuals on the other diets (n = 139). Magical thinking, constricted affect, social anxiety, cognitive perceptual, interpersonal scores and total SPQ-BR scores remained significant when we controlled for body mass index (BMI) and age. Disorganised features were not influenced by ketogenic diet. The longer individuals adhered to a ketogenic diet the lower their positive and negative schizotypy traits. These findings highlight that ketogenic diet is associated with lower non-clinical schizotypal personality traits. Our results suggest that ketogenic diet might have potential prophylactic properties for individuals at-risk for psychosis.

PGR - 2 Demons In The Mirrors: A Childhood Case Report of 22q11.2 Deletion Syndrome First Addressed By Tele-Neuropsychological Evaluation During The COVID-19 Lockdown.

22q11.2 Deletion Syndrome (22q11DS) results in physical, cognitive, and behavioral issues. Although it is the most common microdeletion syndrome, there remains a high prevalence of delayed diagnosis. Its heterogeneous phenotypic presentation lead to differing considerations for early diagnostic identification. If initial symptomatology includes behavioral and cognitive disturbance, it is likely for such individuals to be referred first for neuropsychological testing before genetic testing. This case will expand upon diagnostic identification of 22q11DS. A 12-year-old, 5-years educated, white female was seen for tele-neuropsychological evaluation due to COVID-19 restrictions in December 2020. Patient's mother reported concern regarding sudden and worsening behavioral changes including hallucinations, unusual affects, odd beliefs, academic decline, illegible handwriting, attention and memory issues, and behavioral problems in school to the point of removal. Overall performance on the Meyers Neuropsychological Battery was severely impaired. See uploaded image file for specific test findings. Speech, affect, and behavior were notable during examination. Diagnoses included schizophrenia (provisional) and specific learning disorder with reading impairment (historical). Immediate neurology consultation was recommended. Later EEG, brain MRI, and CSF were unremarkable. Acute metabolic etiology was ruled out. Subsequent genetic testing revealed 22q11DS. Diagnostic identification of 22q11DS and resulting access to care management heavily depends on initial symptom presentation. In this specific case, the COVID-19 lockdown created barrier to sufficient services. This case expands upon knowledge of the cognitive profile of 22q11DS and calls upon increased awareness. Targeted improvement of neurocognition potentially protects against cognitive decline related to psychotic symptoms, and thus neuropsychologists play a vital role in referral to such resources.

The conspiratorial mind: A meta-analytic review of motivational and personological correlates.

A tidal wave of research has tried to uncover the motivational and personological correlates of conspiratorial ideation, often studying these two classes of correlates in parallel. Here, we synthesize this vast and piecemeal literature through a multilevel meta-analytic review that spanned 170 studies, 257 samples, 52 variables, 1,429 effect sizes, and 158,473 participants. Overall, we found that the strongest correlates of conspiratorial ideation pertained to (a) perceiving danger and threat, (b) relying on intuition and having odd beliefs and experiences, and (c) being antagonistic and acting superior. Considerable heterogeneity was found within these relations--especially when individual variables were lumped together under a single domain--and we identified potential boundary conditions in these relations (e.g., type of conspiracy). Given that the psychological correlates of conspiratorial ideation have often been classified as belonging to one of two broad domains-motivation or personality-we aim to understand the implications of such heterogeneity for frameworks of conspiratorial ideation. We conclude with directions for future research that can lead to a unified account of conspiratorial ideation. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Factor structure and item response of psychosis symptoms among Kenyan adults

BackgroundThe aim of this study was to evaluate the construct validity of the psychosis module of the Mini International Neuropsychiatric Interview version 7.0.2 (MINI-7). MethodWe utilized data collected from 2738 participants with a primary psychotic or bipolar disorder. Participants were drawn from two Kenyan sites of a large multi-center neuropsychiatric genetic study. The factor structure of the MINI-7 psychosis items were explored using confirmatory factor analyses (CFA) and Item Response Theory approach, for the full sample and by gender. ResultsThe CFA revealed that a 1-factor model provided adequate fit for the MINI-7 psychosis items for the full sample (x2 = 397.92, df = 35, p < .0001; RMSEA = 0.06; CFI = 0.92; TLI = 0.90) as well as for the female (x2 = 185.16.92, df = 35, p < .0001; RMSEA = 0.06; CFI = 0.93; TLI = 0.91) and male groups (x2 = 242.09, df = 35, p < .0001; RMSEA = 0.06; CFI = 0.92; TLI = 0.89). Item thresholds for the full sample, and female and male groups were highest for ‘odd beliefs’ (−1.42, −1.33, and −1.51 respectively) and lowest for ‘visual hallucinations’ (−0.03, −0.04, and −0.01 respectively). LimitationsOur study used a hospital-based population, which may have excluded patients with milder psychotic symptoms. Findings may therefore not be generalizable to the community setting. ConclusionsOur findings indicate good construct validity of the MINI-7 psychosis module, and provides support for use of the tool in diagnosing psychotic disorders in clinical settings in Kenya.

Positive schizotypy is associated with amplified mnemonic discrimination and attenuated generalization

Tendency to experience inaccurate beliefs alongside perceptual anomalies constitutes positive schizotypal traits in the general population and shows continuity with the positive symptoms of schizophrenia. It has been hypothesized that the positive symptomatology of schizophrenia, and by extension, the odd beliefs and unusual perceptual experiences in the general population, are associated with specific alterations in memory functions. An imbalance between memory generalization and episodic memory specificity has been proposed on several counts; however, the direction of the imbalance is currently unclear. Here, we evaluated the association between positive schizotypy, and memory alterations related to hippocampal computations in a general population sample enriched for positive schizotypy. We found that memory generalization is attenuated while memory specificity is elevated in participants with more pronounced positive schizotypal traits. Our findings show that people who are prone to irrational beliefs and unusual experiences also show measurable alterations in memory and likely have difficulty grasping the global picture and rather be overpowered by fragments of information.

A network analysis on the relationship between loneliness and schizotypy

BackgroundSchizotypy is a multidimensional personality trait related to the heightened risk for the development of schizophrenia spectrum disorders. While it has been suggested that loneliness may be associated with schizotypy in general, whether it relates to the specific schizotypal traits differentially remains unknown. Besides, as loneliness often co-occurs with depression and anxiety, it is important to delineate its relationship with schizotypy in consideration of these co-occurring emotional disturbances. MethodsA demographically diverse sample of young people was obtained from multiple sources. The validated sample consisted of 2089 participants (68.4% female, age range: 18–30). The structural relationship between loneliness and schizotypy was modelled using a network analytic approach. The Gaussian graphical model with loneliness and nine schizotypal traits as nodes was first estimated without, and then with adjustment for the levels of depressive and anxiety symptoms. Edges were estimated as unique associations between nodes. Results‘Suspiciousness’, ‘odd beliefs or magical thinking’, ‘no close friends’, ‘constricted affect’ and ‘excessive social anxiety’ were linked to loneliness directly. Loneliness was found to be more strongly associated with ‘suspiciousness’ and ‘no close friends’ than other schizotypal traits. After adjustment for the levels of depressive and anxiety symptoms, the above direct edges remained robust. LimitationsThe use of cross-sectional data indicated only undirected associations between variables. ConclusionsLoneliness was more strongly linked to some schizotypal traits than others, with the relationships maintaining above and beyond the effects of anxiety and depression. These findings warrant further investigation of the specific relationships between loneliness and individual schizotypal traits.

Borderline Personality Disorder: Clinical Guidelines for Treatment.

Borderline personality disorder (BPD) is fundamentally a syndrome composed of symptoms (primarily of emotional dysregulation) and a number of true personality traits (such as inordinate anger, impulsivity, and a tendency to stress-related paranoid ideation). Whereas schizotypal personality disorder, with its cognitive peculiarities (ideas of reference, odd beliefs, eccentric speech), is closely linked as a genetic condition-"borderline" to the major condition schizophrenia-BPD is less closely linked to bipolar disorder. Some cases of BPD are linked genetically to and are in the "border" of bipolar disorder. But the condition can also arise from adverse post-natal factors: parental cruelty or neglect, or incest. In some BPD patients, both are present: risk genes for bipolar disorder and adverse conditions within the family. The genetic risk is often overlooked. To avoid this, initial evaluations should always include a careful and extensive family history for mood disorders, and should extend out to grandparents, aunts, uncles, and cousins. Where the history suggests a genetic link to bipolar disorder, a mood stabilizer such as lithium or lamotrigine, even in modest doses, may be particularly beneficial, more so than conventional antidepressants. In some patients, ADHD was present in childhood, BPD was diagnosed during or after puberty, and a form of bipolar disorder becomes apparent during their 20s. As for the psychotherapeutic component, the patient's cognitive style and capacity for introspection will help determine whether a primarily expressive (psychoanalytically oriented) technique is preferable or a primarily cognitive-behavioral technique. Flexibility is necessary, since during emotional crises, supportive and limit-setting interventions will be needed, along with psychotropic medications, and where necessary, programs to help combat substance abuse (which is common among patients with BPD).

The Interplay Between Postsynaptic Striatal D2/3 Receptor Availability, Adversity Exposure and Odd Beliefs: A [11C]-Raclopride PET Study

Between unaffected mental health and diagnosable psychiatric disorders, there is a vast continuum of functioning. The hypothesized link between striatal dopamine signaling and psychosis has guided a prolific body of research. However, it has been understudied in the context of multiple interacting factors, subclinical phenotypes, and pre-postsynaptic dynamics. This work investigated psychotic-like experiences and D2/3 dopamine postsynaptic receptor availability in the dorsal striatum, quantified by in vivo [11C]-raclopride positron emission tomography, in a sample of 24 healthy male individuals. Additional mediation and moderation effects with childhood trauma and key dopamine-regulating genes were examined. An inverse relationship between nondisplaceable binding potential and subclinical symptoms was identified. D2/3 receptor availability in the left putamen fully mediated the association between traumatic childhood experiences and odd beliefs, that is, inclinations to see meaning in randomness and unfounded interpretations. Moreover, the effect of early adversity was moderated by a DRD2 functional variant (rs1076560). The results link environmental and neurobiological influences in the striatum to the origination of psychosis spectrum symptomology, consistent with the social defeat and diathesis-stress models. Adversity exposure may affect the dopamine system as in association with biases in probabilistic reasoning, attributional style, and salience processing. The inverse relationship between D2/3 availability and symptomology may be explained by endogenous dopamine occupying the receptor, postsynaptic compensatory mechanisms, and/or altered receptor sensitivity. This may also reflect a cognitively stabilizing mechanism in non-help-seeking individuals. Future research should comprehensively characterize molecular parameters of dopamine neurotransmission along the psychosis spectrum and according to subtype profiling.

The Relationship Between Multisensory Temporal Processing and Schizotypal Traits.

Recent literature has suggested that deficits in sensory processing are associated with schizophrenia (SCZ), and more specifically hallucination severity. The DSM-5's shift towards a dimensional approach to diagnostic criteria has led to SCZ and schizotypal personality disorder (SPD) being classified as schizophrenia spectrum disorders. With SCZ and SPD overlapping in aetiology and symptomatology, such as sensory abnormalities, it is important to investigate whether these deficits commonly reported in SCZ extend to non-clinical expressions of SPD. In this study, we investigated whether levels of SPD traits were related to audiovisual multisensory temporal processing in a non-clinical sample, revealing two novel findings. First, less precise multisensory temporal processing was related to higher overall levels of SPD symptomatology. Second, this relationship was specific to the cognitive-perceptual domain of SPD symptomatology, and more specifically, the Unusual Perceptual Experiences and Odd Beliefs or Magical Thinking symptomatology. The current study provides an initial look at the relationship between multisensory temporal processing and schizotypal traits. Additionally, it builds on the previous literature by suggesting that less precise multisensory temporal processing is not exclusive to SCZ but may also be related to non-clinical expressions of schizotypal traits in the general population.

Predictors of belief in conspiracy theory: The role of individual differences in schizotypal traits, paranormal beliefs, social dominance orientation, right wing authoritarianism and conspiracy mentality

Many different predictors for belief in conspiracy theories have been empirically validated in different studies. The current study considers the relative contribution of individual differences in dimensions of schizotypal personality, social dominance orientation (SDO), right wing authoritarianism (RWA), paranormal beliefs (PB) and the newer construct of conspiracy mentality (CM) on belief in conspiracy theories. For predicting belief in specific conspiracy theories, we applied Path analyses with a large convenience sample (N = 883, 62% women) of students from Norway, a highly gender egalitarian country, allowing us to consider the effects of mediators and gender moderation in a specified model. Schizotypal personality dimensions Odd Beliefs and Paranoid Ideation predicted different mediators, and their effects on belief in conspiracy theories were totally mediated. The mediating variables (SDO, RWA, PB, and CM) were all unique predictors of belief in conspiracy theories, with CM having the largest contribution for both sexes. Explorative analyses of the specified model across gender suggest that the model for men and women is not equivalent. Results are discussed in light of the predictive contribution of especially conspiracy mentality.

Actors of the most fiendish character: Explaining the associations between the Dark Tetrad and conspiracist ideation

It remains unclear why those scoring high on certain aspects of the Dark Tetrad (i.e., Machiavellianism, narcissism, psychopathy, and sadism) are more inclined to believe in conspiracy theories. The present study (N = 474) aimed to clarify this issue by investigating the associations between the facets of the Dark Tetrad traits and conspiracist ideation in the context of five potential mediators. At least one facet of every Dark Tetrad trait was associated with conspiracist ideation, and nearly every association could be attributed, in part, to the tendency for those with aversive personalities to entertain odd beliefs, be fatalistic, and distrust others. Contrary to what the prior research might suggest, these results indicate that the conspiracist ideation found among those scoring high in the Dark Tetrad traits is the result of some shared feature of the traits rather than a feature that is unique to each trait.

Does cannabis use predict psychometric schizotypy via aberrant salience?

Cannabis can induce acute psychotic symptoms in healthy individuals and exacerbate pre-existing psychotic symptoms in patients with schizophrenia. Inappropriate salience allocation is hypothesised to be central to the association between dopamine dysregulation and psychotic symptoms. This study examined whether cannabis use is associated with self-reported salience dysfunction and schizotypal symptoms in a non-clinical population. 910 University students completed the following questionnaire battery: the cannabis experience questionnaire modified version (CEQmv); schizotypal personality questionnaire (SPQ); community assessment of psychic experience (CAPE); aberrant salience inventory (ASI). Mediation analysis was used to test whether aberrant salience mediated the relationship between cannabis use and schizotypal traits. Both frequent cannabis consumption during the previous year and ASI score predicted variation across selected positive and disorganised SPQ subscales. However, for the SPQ subscales ‘ideas of reference’ and ‘odd beliefs’, mediation analysis revealed that with the addition of ASI score as a mediating variable, current cannabis use no longer predicted scores on these subscales. Similarly, cannabis use frequency predicted higher total SPQ as well as specific Positive and Disorganised subscale scores, but ASI score as a mediating variable removed the significant predictive relationship between frequent cannabis use and ‘odd beliefs’, ‘ideas of reference’, ‘unusual perceptual experiences’, ‘odd speech’, and total SPQ scores. In summary, cannabis use was associated with increased psychometric schizotypy and aberrant salience. Using self-report measures in a non-clinical population, the cannabis-related increase in selected positive and disorganised SPQ subscale scores was shown to be, at least in part, mediated by disturbance in salience processing mechanisms.

2.13 ADOLESCENT CANNABIS USE AND PREADOLESCENT VULNERABILITY FACTORS DIFFERENTIALLY CONTRIBUTE TO THE DEVELOPMENT OF PARANOID AND SCHIZOTYPAL SYMPTOMS IN YOUNG ADULTHOOD

Cannabis is the most commonly used drug among adolescents and youth in the United States. Emerging evidence suggests that cannabis use increases the risk of psychosis. Paranoia (the unfounded fear that others intend one harm), and schizotypy (aberrant perceptions, odd beliefs, and thought distortions in the absence of overt psychosis) encompass core psychotic symptom domains and cumulatively serve as latent vulnerability for psychosis. Understanding the relationships between cannabis use, paranoia, and schizotypy may enhance our understanding of how cannabis use serves as a risk factor for psychotic spectrum disorders.

Aberrant Salience Across Levels of Processing in Positive and Negative Schizotypy.

Schizotypy is a multidimensional construct conceptualized as the expression of the underlying vulnerability for schizophrenia. Certain traits of positive schizotypy, such as odd beliefs, unusual perceptual experiences, suspiciousness, and referential thinking show associations with aberrant salience. Positive schizotypy may involve hyper-attribution of salience toward insignificant events, whereas negative schizotypy may involve hypo-attribution of salience, even toward important events. Attribution of salience is thought to involve dopamine-mediated processes, a mechanism that is disrupted in schizotypy; however, little is known about the cognitive processes potentially underlying salience attribution. The present study assessed the relationship between aberrant salience and latent inhibition (LI), as well as their associations with positive and negative schizotypy. Salience was measured at various stages of processing, including visual salience, attributions of salience to contingency illusions, and self-reported experience of salience. Schizotypy traits were differentially associated with self-reported aberrant salience experiences: positive schizotypy showed positive associations (β = 0.67, f2 = 0.82, large effect) and negative schizotypy showed inverse associations (β = −0.20, f2 = 0.07, small effect). However, neither schizotypy dimension was associated with visual salience, contingency illusions, or LI. Salience processing across perceptual, cognitive, and experiential levels likely involves different mechanisms, some of which may not show major disruption in subclinical manifestations of schizotypy.

The Michigan Odd Beliefs Scale: A Measure of Suggestibility as Assessed by Endorsement of Urban Myths

We describe the development and psychometric characteristics of the Michigan Odd Beliefs Suggestibility Scale (MOBS), a brief measure of suggestibility as measured by the endorsement of urban myths. One hundred fifteen undergraduate students (57% female, mean age=20.3 years [SD=4.5]) were administered 21 “true” or “false” items, consisting of “urban myths” which are popularly referenced. The MOBS had a mean endorsement of 6.4 items (SD=3.3), with an endorsement of greater than 12 items occurring in fewer than five percent of participants.

Lifetime prevalence and potential determinants of psychotic experiences in the general population of Qatar.

To estimate the lifetime prevalence and potential determinants of psychotic experience(s) (PEs) in the general population of Qatar - a small non-war afflicted, conservative, high-income, middle-eastern country with recent rapid urbanization including an influx of migrants. A probability-based sample (n = 1353) of non-migrants and migrants were interviewed face-to-face and administered a 7-item psychosis screener adapted from the Composite International Diagnostic Interview, the Kessler 6-item psychological distress scale, and the 5 items assessing odd (paranormal) beliefs and magical thinking (OBMT) from the Schizotypal Personality Questionnaire. Using bivariate and logistic regression analyses, lifetime prevalence rates of PEs were estimated then compared before and after adjustment for socio-demographics, Arab ethnicity, psychological distress, and OBMT. Prevalence of PEs was 27.9%. Visual hallucinations were most common (12.8%), followed by persecutory delusions (6.7%) and auditory hallucinations (6.9%). Ideas of reference (3.6%) were least prevalent. PEs were significantly higher in Arabs (34.7%) compared with non-Arabs (16.4%, p < 0.001) with the exception of ideas of reference and paranoid delusions. Female gender was associated with a higher prevalence of PEs in the Arab group only (p < 0.001). Prevalence of PEs was significantly higher among Arabs (48.8% v. 15.8%, p < 0.001) and non-Arabs (35.2% v. 7.3%, p < 0.001) with OBMT. Arab ethnicity (OR = 2.10, p = 0.015), psychological distress (OR = 2.29 p = 0.003), and OBMT (OR = 6.25, p < 0.001) were independently associated with PEs after adjustment for all variables. Ethnicity, but not migration was independently associated with PEs. Evidence linking Arab ethnicity, female gender, and psychological distress to PEs through associations with OBMT was identified for future prospective investigations.

S113. THE ASSOCIATION BETWEEN SCHIZOTYPAL COMPONENTS AND CONSPIRACIST BELIEFS THROUGH COGNITIVE MEDIATORS

BackgroundBelief in conspiracy theories (i.e., a subset of false narratives in which the ultimate cause of an event is believed to be due to a malevolent plot by multiple actors working together) is a widespread and stable aspect of contemporary public opinion. Given such findings, researchers have sought to understand the factors that make someone more or less likely to adopt conspiracist beliefs. More specifically, scholars have focused primarily on social and differential aspects, as well as possible psychopathological elements. These endeavours have led to reports of significant associations between schizotypal facets (odd or magical thinking and, to a lesser extent, ideas of references) and the endorsement of conspiracist beliefs. However, one limitation of extant findings is the assumption that the afore-mentioned relationships are ultimately direct; that is, schizotypal facets are directly associated with conspiracist beliefs, rather than influenced by mediating processes. To overcome this limitation, the present study sought to replicate previous findings by confirming the relationships between components of schizotypy and conspiracist beliefs. Second, this study examined the mediating influence of cognitive processes on this relationship.MethodsAn international online sample of 411 women and men completed measures of schizotypal components (i.e., odd beliefs or magical thinking and ideas of reference), conspiracist beliefs, and cognitive processes (i.e., need for cognition, analytic thinking, and cognitive insight).ResultsThrough path analysis, results indicated associations between both schizotypal facets and conspiracist beliefs in the present sample. Further, there was evidence for the association between analytic thinking and conspiracist beliefs, and between cognitive insight and conspiracist beliefs. Indeed, cognitive insight was found to mediate the association between odd beliefs or magical thinking and ideas of reference with conspiracist beliefs. In addition, analytic thinking provided a mediating link to conspiracy ideation for odd beliefs or magical thinking, this was not found with ideas of reference. Despite an association between odd beliefs or magical thinking and need for cognition, this did not extend to conspiracist beliefs.DiscussionIn summary, the results of this study supported the association between schizotypal components and conspiracist beliefs. However, they also extend previous research by suggesting that cognitive processes mediate this link. That is, although a direct link between these variables may be tenable, it is also important to consider the possible ways in which schizotypy influences cognitive processes, which in turn have an effect on conspiracist beliefs. From a practical point-of-view, this highlights possible intervention routes for reducing conspiracist beliefs, either by targeting schizotypal traits indirectly or cognitive factors directly. While this research addresses schizotypy, patients with psychotic disorders and those with an at-risk mental state have also been shown to have reasoning biases. Therefore, future research, in relation to the clinical spectrum, should consider not only reasoning biases, but an outcome of conspiracy beliefs.

The relationship between schizotypal facets and conspiracist beliefs via cognitive processes

This study sought to replicate previous work showing relationships between components of schizotypy and conspiracist beliefs, and extend it by examining the mediating role of cognitive processes. An international online sample of 411 women and men (mean age = 35.41 years) completed measures of the schizotypal facets of Odd Beliefs or Magical Thinking and Ideas of Reference, conspiracist beliefs, and cognitive processes related to need for cognition, analytic thinking, and cognitive insight. Path analysis confirmed the associations between both schizotypal facets and conspiracist beliefs in the present sample. Confirmatory evidence was found for the association between analytic thinking and conspiracist beliefs, and results also suggested an association between cognitive insight and conspiracist beliefs. Cognitive insight also mediated the link between Odd Beliefs or Magical Thinking and Ideas of Reference with conspiracist beliefs. However, analytic thinking provided a mediating link to conspiracy ideation for Odd Beliefs or Magical Thinking and not Ideas of Reference. Finally, there was an association between Odd Beliefs or Magical Thinking and need for cognition, but this path did not extend to conspiracist beliefs. These results suggest possible mediating roles for analytic thinking and self-certainty between schizotypy and conspiracist beliefs.

The Intricate Relationship between Psychotic-Like Experiences and Associated Subclinical Symptoms in Healthy Individuals.

The interplay between subclinical psychotic, negative, and affective symptoms has gained increased attention regarding the etiology of psychosis spectrum and other mental disorders. Importantly, research has tended to not differentiate between different subtypes of psychotic-like experiences (PLE) although they may not have the same significance for mental health. In order to gain information on the subclinical interplay between specific PLE and other symptoms as well as the significance of PLE for mental health, we investigated their specific associations in 206 healthy individuals (20–60 years, 73 females) using correlational and linear regression analyses. PLE were assessed with the Magical Ideation Questionnaire, the revised Exceptional Experiences Questionnaire, and subscales of the Schizotypal Personality Questionnaire (SPQ). The revised Symptom Checklist 90, the SPQ, and the Physical Anhedonia Scale were used to measure subclinical negative symptoms, affective symptoms, and other symptoms such as, emotional instability. As hypothesized, we found that (1) most affective symptoms and all other subclinical symptoms correlated positively with all PLE, whereas we found only partial associations between negative symptoms and PLE. Notably, (2) magical ideation and paranormal beliefs correlated negatively with physical anhedonia. In the regression analyses we found (3) similar patterns of specific positive associations between PLE and other subclinical symptoms: Suspiciousness was a specific predictor of negative-like symptoms, whereas ideas of reference, unusual perceptual experiences, and dissociative anomalous perceptions specifically predicted anxiety symptoms. Interestingly, (4) ideas of reference negatively predicted physical anhedonia. Similarly, paranormal beliefs were negatively associated with constricted affect. Moreover, odd beliefs were a negative predictor of depression, emotional instability, and unspecific symptoms. Our findings indicated that subtypes of PLE are differentially implicated in psychological functioning and should therefore not be categorized homogeneously. Moreover, paranormal beliefs, odd beliefs, and partly ideas of reference might also contribute to subjective well being in healthy individuals. Our results might serve as a starting point for longitudinal studies investigating the interplay of subtypes of subclinical symptoms along a psychopathological trajectory leading to mental disorders. Importantly, this research might help to improve therapeutic strategies for psychosis prevention.

Psychotic-Like Experiences at the Healthy End of the Psychosis Continuum.

There is increasing evidence pointing toward a continuous distribution of psychotic symptoms and accompanying factors between subclinical and clinical populations. However, for the construction of continuum models, a more detailed knowledge of different types of psychotic-like experiences (PLE) and their associations with distress, functional impairment, and demographic variables is needed. We investigated PLE in a sample of healthy adults (N = 206) incorporating the recently developed revised Exceptional Experiences Questionnaire (PAGE-R). For the first time, the PAGE-R was cross validated with PLE, disorganized-, and negative-like symptoms [Schizotypal Personality Questionnaire (SPQ), Physical Anhedonia Scale (PAS)]. We subjected the PAGE-R to exploratory factor analyses and examined the resulting subtypes of EE for specific associations with contextual factors, valence ratings, socio-demographic variables, and general psychological burden (Revised Symptom-Checklist-90). Correlational cross-validation suggested that the PAGE-R measures facets of PLE. Importantly, we (1) identified three types of exceptional experiences (EE): Odd beliefs, dissociative anomalous perceptions, and hallucinatory anomalous perceptions. Further, the results suggested that even in healthy individuals (2) PLE and EE are indicative of reduced functioning, as reflected by increased psychological burden and lower educational achievement. Moreover, (3) similar sex-differences might exist as in psychotic patients with women reporting more positive-like symptoms and EE but less disorganized-like symptoms than men. Importantly, (4) EE might be differentially implicated in psychological functioning. We suggest that the PAGE-R holds the potential to complement the current assessment of sub-clinical psychosis. However, whereas our results might point toward a continuity of psychotic symptoms with EE and normal experiences, they require replication in larger samples as well as equivalence testing across the psychosis continuum. Future analyses incorporating the PAGE-R might shed more light onto mechanisms that are implicated in the progress or resilience toward clinical illness.