Sex-specific association between schizophrenia polygenic risk and subclinical schizophrenia-related traits.

BACKGROUND: According to the dimensional view of psychiatric disorders, psychosis is expressed as a continuum in the general population. However, the investigation of the putative genetic aetiological continuity between its clinical and subclinical phenotypes has yielded mixed results. We aimed to replicate previous findings regarding the association of polygenic risk for schizophrenia with subclinical traits (i.e., schizotypy traits and psychotic-like experiences), and to examine the role of sex in this association in a large nonclinical sample. METHODS: The Multidimensional Schizotypy Scale and the Community Assessment of Psychic Experiences were assessed in 919 nonclinical participants. Polygenic Risk Scores for schizophrenia (SZ-PRSs) were computed using the PRS-CS method based on the latest genome-wide association study of schizophrenia. Summary statistics derived from the total GWAS sample and stratified by sex were used. Linear regression analyses tested the associations of the SZ-PRSs with the psychometric variables, both in the total sample and by sex. RESULTS: No associations were found between the SZ-PRSs and the positive, negative or disorganized dimensions of schizotypy in the total sample. Likewise, no associations were found with psychotic-like experiences. However, the sex-stratified analyses revealed a male-specific association with positive schizotypy. Similar results were obtained with the PRSs derived from the sex-stratified summary statistics. DISCUSSION: Our results are consistent with the lack of clear evidence of an association between SZ common genetic risk and its subclinical phenotypes. Nevertheless, the male-specific association found suggests that this PRS might explain better the male phenotype, as reported in previous studies. Future studies should put a focus on the role of sex in this association to unravel its sex specificities.

Autistic and schizotypal traits exhibit similarities in their impact on mentalization and adult attachment impairments: a cross-sectional study.

BACKGROUND: Deficits in mentalizing and attachment occur in the autism and schizophrenia spectrum, and their extended traits in the general population. Parental attachment and the broader social environment highly influence the development of mentalizing. Given the similarities in the symptomatology and neurodevelopmental correlates of autism spectrum disorder (ASD) and schizophrenia (SCH), it is crucial to identify their overlaps and differences to support screening, differential diagnosis, and intervention. METHODS: This cross-sectional study utilized questionnaire data from 2203 adults (65.1% female, mean age[SD] = 37.98[9.66]), including participants diagnosed with ASD, SCH, and those exhibiting subclinical traits to investigate the associations between mentalizing, attachment, and perceived social support during adolescence across the autistic and schizotypy spectrum. RESULTS: It was revealed that both autistic and schizotypal traits have comparable effects on insecure adult attachment, primarily through challenges in mentalizing. The impact of mentalizing deficits on adult attachment slightly varies between autistic and schizotypal traits. Conversely, perceived social support during adolescence relates to improved mentalizing and secure adult attachment as a protective factor during development. CONCLUSIONS: These outcomes highlight the significance of supportive therapeutic relationships and community care while suggesting directions for further research and collaborative treatments addressing ASD and SCH, considering the differential impact of mentalizing on adult attachment.

Sleep Matters in Chronotype and Mental Health Association: Evidence from the UK and Germany.

BACKGROUND: There is considerable evidence supporting the elevated risk of mental health problems in individuals with evening chronotype relative to those with morning or intermediate chronotypes. Recent data, however, suggest that this risk may be explained, at least partially, by poor sleep quality. METHODS: This study aimed to further clarify the roles of chronotype and sleep quality in mental health outcomes (depression, anxiety, stress) in young individuals (18-40 years) living in the UK (n = 185) or Germany (n = 209). RESULTS: Consistent with our recent observations in a comparable North Indian sample, we found that poor quality of sleep had significantly positive associations with adverse mental health outcomes both in the UK and Germany-based samples. Significant associations between evening chronotype and poor mental health were also evident, but these associations were fully mediated by poor quality of sleep in both samples. CONCLUSIONS: These observations suggest that efforts to identify sleep disruption in a timely manner and promotion of good sleep may prevent mental health problems, especially in individuals with evening chronotype and other known risks for mental disorders.

Insulin Resistance, Temperament and Personality Traits Are Associated with Anhedonia in a Transdiagnostic Sample.

Anhedonia constitutes a core symptom of major depressive disorder (MDD) mediating the ultimate goal of MDD treatment: functional remission. Anhedonia is also present in other clinical populations, including patients with chronic pain. Recent data links anhedonia to insulin resistance (IR). Some researchers have underlined a different dimension of anhedonia as a temperament/personality trait. The objective of this post-hoc analysis was to explore the links between anhedonia (main outcome) and (1) IR, (2) temperamental, personality, and schizotypy traits (exposures). The study population included patients with MDD, fibromyalgia, and healthy controls. Participants were split into groups: (1) insulin resistant (IR[+] n = 69, HOMA-IR ≥ 2.1) and (2) insulin sensitive (IR[-] n = 69, HOMA-IR < 2.1). Anhedonia was significantly higher in the IR[+] group than the IR[-] group. IR was a predictor of higher anhedonia levels. IR[+] vs. IR[-] participants showed higher levels of anxiety and lower levels of hyperthymic affective temperaments, as well as conscientiousness and emotional stability personality traits. Depressive, irritable, and anxious temperaments, cognitive disorganization, and introvertive anhedonia positively predicted anhedonia, while hyperthymic temperament, conscientiousness, extraversion, and emotional stability traits negatively predicted anhedonia. IR partially mediated the relationship between depressive temperament and anhedonia. In sum, IR, affective temperaments, and personality traits are predictors of anhedonia.

Reduced MMN-indexed auditory change detection in a non-clinical high schizotypy sample.

Schizotypal traits include abnormalities in cognition, behavior, and interpersonal relationships that are similar, yet less severe than psychotic symptomology. It is estimated that approximately 5% of the general population displays psychotic symptoms and experiences that can be considered schizotypal in nature, but there is little research examining the neurological correlates of these traits. The mismatch negativity (MMN) event-related potential is an objective measure of auditory change detection derived from electroencephalography. The current study contributes to the limited body of evidence examining the neurobiological underpinnings of schizotypy in a non-clinical sample using the MMN. Participants were recruited from the general population and divided into high and low-schizotypy groups for comparison. Individuals with high schizotypal traits displayed reduced MMN amplitudes in response to frequency and location deviants, and longer MMN latencies in response to location deviants. Specific sub-traits of schizotypy were uniquely related to frequency and location amplitudes, suggesting the previously reported inconsistencies in the literature may be due to diverse samples and differing deviant tone types. Finally, impulsivity and sensation-seeking likely contributed to the slower processing seen in location deviance detection. Ultimately, the current results provide evidence that the neurobiological abnormalities seen in clinical populations of schizotypal personality disorder and psychosis also extend to non-clinical populations.

How to elicit a negative bias? Manipulating contrast and saturation with the facial emotion salience task.

Introduction: Emotion recognition impairments and a tendency to misclassify neutral faces as negative are common in schizophrenia. A possible explanation for these deficits is aberrant salience attribution. To explore the possibility of salience driven emotion recognition deficits, we implemented a novel facial emotion salience task (FEST). Methods: Sixty-six healthy participants with variations in psychometric schizotypy completed the FEST. In the FEST, we manipulated physical salience (FEST-1: contrast, FEST-2: saturation) of emotionally salient (positive, i.e., happy and negative, i.e., fearful) and non-salient (neutral) facial expressions. Results: When salience was high (increased contrast), participants recognized negative facial expressions faster, whereas neutral faces were recognized more slowly and were more frequently misclassified as negative. When salience was low (decreased saturation), positive expressions were recognized more slowly. These measures were not associated with schizotypy in our sample. Discussion: Our findings show that the match between physical and emotional salience influences emotion recognition and suggest that the FEST is suitable to simulate aberrant salience processing during emotion recognition in healthy participants.

Examining measures of schizotypy for gender and racial bias using item response theory and differential item functioning.

Schizotypy involves schizophrenia-like traits and symptoms, with the Wisconsin Schizotypy Scales (WSS) being frequently used in previous research. There is some evidence that schizophrenia-spectrum symptom levels, including when using the WSS, might vary both by gender and by race and ethnicity. However, previous research has rarely examined to what extent the WSS show gender and racial bias. Further, this has not been previously examined for the Cognitive Slippage Scale, a measure of disorganized schizotypy. In this study, we examined biases for a subset of items from the WSS in a large sample of undergraduate students (n = 21,829). Using item response theory to test for levels of differential item functioning (DIF), we found some evidence of problematic DIF for all scales, including for negative, positive, and disorganized schizotypy scales. There was evidence of problematic DIF especially by gender and for Black and Multiracial participants. Overall, the current results suggest that gender and/or racial bias on these scales should be an important consideration in using these scales and our results could have implications for assessment of schizophrenia-spectrum symptoms.

Are psychotic-like experiences associated with aberrant prosocial decision-making behavior?

Introduction: Deficits in social functioning and decision-making are well-documented in schizophrenia, but their relationship with positive symptoms and social conflicts is poorly understood. We created a new paradigm based on the Dictator Game (DG) to explore differences in social decision-making between individuals experiencing high levels of psychotic-like experiences (PLEs), particularly hallucinations and delusions, and controls with less PLEs. Methods: A large community sample (N = 1,161) completed a DG in an online study whereby extreme groups were built based on the positive subscale of the CAPE. Results: Overall, participants experiencing PLEs did not act less prosocial than controls but showed a somewhat aberrant decision-making behavior, particularly a pattern of behaving more prosocial in fair situations and generally favoring punishment over compensation relative to controls. Mediation analyses suggest that measures of empathy and Machiavellism have predictive power for prosocial behavior beyond group status. Discussion: The present study raises the possibility that individuals with high levels of PLEs may be less able to adapt their behavior to the situation at hand than controls. These irregularities might be due to deficits in social cognition which may elicit conflict, thus compromising social functioning and possibly contributing to the formation of positive symptoms.

Duration mismatch negativity under varying deviant conditions in individuals with high schizotypal traits.

Background: Although impaired auditory mismatch negativity (MMN) has consistently been found in individuals with schizophrenia, there are few and inconsistent reports on nonclinical individuals with schizotypy. To date, no studies have thoroughly assessed MMN with different degrees of deviant oddballs in nonclinical schizotypal samples. The aim of this study was to examine the extent of duration MMN (dMMN) amplitudes under two deviant duration conditions (large and small) in nonclinical participants with high schizotypal traits. Methods: An extreme-group design was utilized, in which 63 participants from the schizotypy and control groups were selected from a pool of 1519 young adults using the Schizotypal Personality Questionnaire (SPQ). MMN was measured using passive duration oddball paradigms. Basic demographic information and musical backgrounds were assessed and matched, while depression and anxiety were evaluated and controlled for. The repeated measures analysis of covariance was utilized to evaluate differences in dMMN between groups. The Bonferroni correction was applied for multiple comparisons. Partial correlation and multiple linear regression analyses were conducted to investigate the association between dMMN amplitudes and SPQ scores. Results: The amplitudes of dMMN at Cz were significantly increased under the large deviance condition in nonclinical schizotypal individuals (F = 4.36, p = .04). Large-deviance dMMN amplitudes at Fz were positively correlated with mild cognitive-perceptual symptoms in the control group (rp = .42, p = .03). However, as schizophrenia-like symptoms worsened and approached the clinical threshold for schizophrenia, small-deviance dMMN amplitudes at Cz showed negative associations with the cognitive-perceptual factor in the schizotypy group (rp = -.40, p = .04). Conclusion: These results suggest the importance of considering the degree of deviation in duration when implementing the auditory oddball paradigm among nonclinical participants with schizotypal traits. In addition, our findings reveal a potential non-linear relationship between bottom-up auditory processing and the positive dimension of the schizophrenia spectrum.

Variations in positive well-being as a function of the interaction between paranormal belief and schizotypy.

This study examined variations in positive well-being as a function of paranormal belief and schizotypy. A sample of 2,362 United Kingdom-based respondents completed self-report measures assessing paranormal belief, schizotypy, positive well-being (meaning in life, satisfaction with life, and self-esteem), paranormal experience, and belief in conspiracies. The paranormal belief was most strongly related to the cognitive-perceptual factor of schizotypy. Both paranormal belief and the cognitive-perceptual factor were associated with reporting paranormal experiences and endorsement of conspiracist beliefs. Despite commonality, paranormal belief and schizotypy were differentially related to well-being. Paranormal belief correlated positively with meaning in life (presence and search) and satisfaction with life. Schizotypy correlated negatively with presence, satisfaction with life, and self-esteem and positively with search. Latent profile analysis identified four subgroups: Profile 1, low belief and schizotypy (49% of the sample); Profile 2, low belief and cognitive-perceptual, moderate interpersonal and disorganised (13.6%); Profile 3, high belief, moderate cognitive-perceptual and interpersonal, low disorganised (24.3%); and Profile 4, high belief and schizotypy (13.1%). Multivariate analysis of variance (MANOVA) found that low belief with mixed schizotypy was associated with lower presence, and low belief and schizotypy (vs. high) were related to higher presence. Paranormal belief and schizotypy were associated with greater search, higher scores on paranormal experiential factors, and endorsement of generic conspiracist beliefs. Finally, lower belief and schizotypy were concomitant with higher satisfaction with life and self-esteem. Overall, paranormal belief was related to positive well-being, whereas schizotypy was associated with lower positive wellbeing.

Investigating the impact of schizophrenia traits on attention: the role of the theta band in a modified Posner cueing paradigm.

Joint attention is an indispensable tool for daily communication. Abnormalities in joint attention may be a key reason underlying social impairment in schizophrenia spectrum disorders. In this study, we aimed to explore the attentional orientation mechanism related to schizotypal traits in a social situation. Here, we employed a Posner cueing paradigm with social attentional cues. Subjects needed to detect the location of a target that is cued by gaze and head orientation. The power in the theta frequency band was used to examine the attentional process in the schizophrenia spectrum. There were four main findings. First, a significant association was found between schizotypal traits and attention orientation in response to invalid gaze cues. Second, individuals with schizotypal traits exhibited significant activation of neural oscillations and synchrony in the theta band, which correlated with their schizotypal tendencies. Third, neural oscillations and synchrony demonstrated a synergistic effect during social tasks, particularly when processing gaze cues. Finally, the relationship between schizotypal traits and attention orientation was mediated by neural oscillations and synchrony in the theta frequency band. These findings deepen our understanding of the impact of theta activity in schizotypal traits on joint attention and offer new insights for future intervention strategies.

The relationship between script memory for everyday events and schizotypy: an investigation through a development of Japanese Situational Feature Recognition Test.

Background: Script memory is stored information about a sequential structure of an activity (e.g., going shopping), including what actors do, the purpose of the activity, and the likely consequences of the actor's actions. It has been reported that script memory is impaired among schizophrenia patients. The present research investigated the relationship between schizotypal personality tendencies (schizotypy) and script memory by testing Japanese individuals. Method: First, a new test to measure the intactness of the script memory was created by asking the public to report activities they often perform and what behaviors each activity contains. The test contains 15 everyday activities, each accompanied by 15 behavior choices, either strongly associated, completely unrelated, or weakly associated with the activity. Next, undergraduate participants were presented with the test and chose appropriate behaviors for each activity (Study 1 and 2). Their extent of schizotypy was measured using Schizotypal Personality Questionnaire Brief (SPQ-B). Study 3 targeted the public of various ages. In addition to Study 2 procedure, participants reported the extent of psychological burden for performing each activity, their life satisfaction, and subjective evaluation of their memory ability. Results: All studies consistently found that the script memory performance was worse for individuals with higher schizotypy. Signal detection indices for accurate discrimination between correct and incorrect choices, which were A' in Study 1 and C in Study 2 and 3, negatively correlated with the SPQ-B scores (r = -0.16, -0.11, -0.17, respectively). Study 3 found that the relationship between schizotypy and memory task performance was mediated by the extent of psychological burden. When a signal detection index (d') for the memory task was regressed on the SPQ-B, while the psychological burden scores being a mediator, the mediation effect was significant (B = 0.003, SE = 0.001, 95% CI [0.001, 0.005]). Conclusion: Individuals with higher schizotypy seem to associate unrelated behaviors to an event, forming script memory with irrelevant information, maybe due to the schizotypy symptom of having peculiar thoughts. The newly created test must be validated using a clinical population to expand its potential to be used in clinical research.

Taking the edge off: a feasibility randomized controlled trial of an online mindfulness-based intervention to reduce suspiciousness/paranoia in high positive schizotypy.

Positive schizotypy can uniquely predict the development of psychosis with suspiciousness/paranoia having emerged as a key risk factor, pointing to significant worth in reducing this aspect in individuals with high positive schizotypy. Reduced paranoia in the general population following brief online mindfulness training has been previously reported. This study investigated the feasibility of a 40-day online mindfulness-based intervention (MBI) (n = 12) in the individuals with high positive schizotypy characterized by high suspiciousness/paranoia and to estimate its effect on paranoia as compared with an active control condition using reflective journaling (n = 12). The outcome measures were self-reported trait and VR-induced state paranoia, completed at baseline, after 10 days and post-intervention. The feasibility criteria included retention, adherence, engagement, and acceptability. There was 100% retention, excellent adherence to content and engagement, with an average MBI session completion rate of 91%. Acceptability, indexed by a self-rated motivation to continue practice post-intervention, was also high. No MBI effect on trait paranoia was observed; however, the MBI group showed a reduction in the VR-induced state paranoia with a medium-to-large effect (d = 0.63). The findings support conducting larger-scale randomized controlled trials to evaluate the effects of online MBIs on reducing suspiciousness/paranoia to mitigate psychosis risk in individuals with high positive schizotypy. Clinical Trial Registration:https://www.isrctn.com/, identifier ISRCTN78697391.

Social Activity in Schizotypy: Measuring Frequency and Enjoyment of Social Events.

Improving social functioning deficits-a core characteristic of schizophrenia-spectrum disorders-is often listed by patients as a key recovery goal. Evidence suggests that social deficits also extend to people with schizotypy, a group at heightened risk for psychotic and other psychopathological disorders. One challenge of social functioning research in schizotypy is understanding whether social deficits arise from receiving less pleasure from social activities or from participating less in high-pleasure activities. However, limited information exists on what constitutes highly pleasurable, common social activities. In this study, 357 college students rated the frequency and enjoyment of 38 social activities. Our aims were to categorize activities based on their frequency and enjoyment, and whether these correlated with validated social functioning and schizotypy measures. We found that social activities could be characterized based on their frequency and enjoyment and created a frequency-enjoyment matrix that could be useful for future studies. Activities were correlated with social functioning, generally reaching a small effect size level, with increasing frequency and enjoyment showing associations with greater social functioning. Further, negative and disorganized-but not positive-traits were associated with less engagement and pleasure. Although follow-up studies in community samples are needed, our findings have the potential to help researchers and clinicians better understand which activities participants are more likely to engage in and derive pleasure from. The findings may also illustrate the extent to which social deficits may be due to less engagement or less pleasure from social activities, as well as which aspects of schizophrenia-spectrum disorders are associated with these facets of social functioning.

Abnormalities in emotion regulation are associated with negative, but not positive or disorganized schizotypy: An experience sampling study.

BACKGROUND: Schizotypy, a multidimensional construct with positive, negative, and disorganized dimensions, represents a vulnerability marker for the development of schizophrenia. Although there has been increasing evidence linking schizotypy to emotion regulation (ER) deficits, the specific association between different schizotypal dimensions and alterations in ER strategy use in daily life remains poorly understood. METHODS: Using the experience sampling method (ESM), the present study examined the associations between positive, negative, and disorganized schizotypy and ER strategy use in daily life in a nonclinical young adult sample (N = 258). Participants were instructed to report their ER strategy use 5 times a day for 14 days. Four adaptive ER strategies (reflection, reappraisal, social sharing, and distraction) and two maladaptive ER strategies (suppression and rumination) were included. RESULTS: Multilevel modeling analyses showed that positive schizotypal traits predicted greater use of adaptive ER strategies, while negative schizotypal traits predicted less use of adaptive ER strategies and more frequent use of emotional suppression in daily life. No associations between disorganized schizotypal traits and any ER strategy use were found. CONCLUSION: Schizotypy dimensions are differentiated by preferences for different ER strategies in daily life. The findings suggest a strong association between negative schizotypy and notable dysfunctions in ER, emphasizing the significance of negative schizotypy as a vulnerability factor for psychosis.

The association between discourse production and schizotypal personality traits.

Discourse abnormalities are a prominent feature in schizophrenia spectrum disorders, including poor lexical diversity, and have been found to differentiate patients from healthy subjects. However, discourse processing in individuals with high schizotypal personality traits is less understood and is often overshadowed by research on clinical psychotic symptoms. In the present study, we examined schizotypal traits at a non-clinical threshold and their association with lexical diversity and discourse coherence using two automated Natural Language Processing (NLP) tools - Type-Token-Ratio (TTR) measures from the Tool for the Automatic Analysis of Lexical Diversity (TAALED) and discourse coherence using sentence-level average cosign similarity with FastText to assess sentence similarity. 276 college students completed the full assessment including the Schizotypal Personality Questionnaire- Brief Revised (SPQ-BR) and recorded a speech sample describing a detailed painting. Results revealed that high schizotypal traits, specifically positive traits, were associated with lower lexical diversity and higher sentence similarity. Our findings suggest that even when clinically significant symptoms are not present, discourse abnormalities are present in healthy populations with high ST. The stronger association with positive traits suggests that theories of perseveration and top-down processing may warrant further investigation in schizophrenia-spectrum disorders.

Investigation of Siblings of Patients Diagnosed with Substance-Induced Psychotic Disorder in terms of Cognitive Functions and Clinical High-Risk State for Psychosis.

OBJECTIVE: This study aimed to investigate the influence of familial predisposition on substance-induced psychosis among healthy siblings of patients diagnosed with substance-induced psychotic disorder, who themselves lack any family history of psychotic disorders. Additionally, the study aimed to explore clinical high-risk states for psychosis, schizotypal features, and neurocognitive functions in comparison to a healthy control group. METHOD: The study compared healthy siblings of 41 patients diagnosed with substance-induced psychotic disorder with 41 healthy volunteers without a family history of psychotic disorders, matching age, gender, and education. Sociodemographic and clinical characteristics of participants were obtained using data collection forms. The Comprehensive Assessment of At-Risk Mental States (CAARMS) and the Structured Interview for Schizotypy-Revised Form (SIS-R) scales were utilized to assess clinical high risk for psychosis. Neurocognitive functions were evaluated with digit span test (DST), trail making test part A-B (TMT), verbal fluency test (VFT), and Stroop test (ST). RESULTS: Analysis using the CAARMS scale revealed that 39% of siblings and 7.3% of the control group were at clinically high risk for psychosis, indicating a significant difference in rates of psychotic vulnerability. Comparison between siblings and the control group showed significant differences in mean SIS-R subscale scores, including social behavior, hypersensitivity, referential thinking, suspiciousness, illusions, and overall oddness, as well as in mean neurocognitive function scores, including errors in TMT-A, TMT-B, and VFT out-of-category errors, with siblings exhibiting poorer performance. CONCLUSION: Our study suggests that healthy siblings of patients with substance-induced psychosis exhibit more schizotypal features and have a higher risk of developing psychosis compared to healthy controls. Additionally, siblings demonstrate greater impairment in attention, response inhibition, and executive functions compared to healthy controls, indicating the potential role of genetic predisposition in the development of substance-induced psychotic disorder.

Schizotypal traits and anomalous perceptual experiences are associated with greater visual temporal acuity.

One of the main tasks of the human visual system is to organize the temporal flow of visual events into meaningful patterns. It has been suggested that segregation/integration of continuous visual stimuli relies on temporal windows that are phase-locked to brain oscillations in the alpha frequency range (~10 Hz). From a behavioral point of view, the balance between integration and segregation is reflected in visual temporal acuity: the ability to perceive a small temporal gap between two identical stimuli. Disruption of this balance may lead to impairment of perceptual organization processes. Notably, schizophrenia, a condition characterized by unusual perceptual experiences, has been associated with abnormal temporal processing of sensory stimuli and aberrant oscillations. We asked a large cohort of healthy participants to complete an online version of the two-flash fusion task and two questionnaires for schizotypal personality traits to investigate individual differences in the temporal resolution of perception, particularly its relationship with anomalous perceptual experiences. We found that two-flash discrimination acuity declines with age and that schizotypal traits are associated with better performances. Although this association was strong for perceptual and cognitive subscales, we found that this result could not be attributed to response biases (e.g., hallucination of two flashes). While these results appear to contrast with findings of slower alpha rhythms and sensory processing in schizotypy, we propose that a faster visual rate could be the consequence of an oscillopathy or a disconnection between different sensory modalities and their physiological pacemaker.