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.

Factor analysis of the Chinese version of the Autism Spectrum Quotient 10 and its association with schizotypal traits in adolescents and young adults in Hong Kong.

BACKGROUND: There is evidence suggesting that autistic traits are associated with schizotypal traits. This study examined the factor structure of the Autism Spectrum Quotient 10 (AQ-10) and its associations with schizotypal traits (measured by the Schizotypal Personality Questionnaire-Brief [SPQ-B]) in a cohort of Chinese adolescents and young adults. METHODS: Invitation letters, stratified by locations and housing types, were randomly sent to individuals aged 15 to 24 years for participation. Assessments were made using face-to-face or online interviews. Autistic traits were assessed using the Chinese version of the AQ-10. Schizotypal personality traits were assessed using the Chinese version of the 22-item SPQ-B. RESULTS: In total, 395 male and 536 female participants (mean age, 19.93 years) were recruited between July 2020 and May 2021. Exploratory factor analysis of the AQ-10 yielded three factors (theory of mind, task switching, and attention deficits) explaining 55.11% of the total variance. Autistic traits were positively correlated with schizotypal traits of disorganised features (r = 0.21, p < 0.001), interpersonal relationship deficits (r = 0.19, p < 0.001), and cognitive-perceptual deficits (r = 0.11, p = 0.001). CONCLUSION: In Chinese adolescents and young adults, autistic traits, especially task switching and attention deficits (compared with theory of mind) are more closely correlated with schizotypal personality traits. Disentangling the overlapping and diametrical structure of autistic traits and schizotypal traits may help understand their aetiologies, assessment, and interventions.

Comparison of trait and state mind wandering among schizotypal, subclinically depressed, and control individuals.

BACKGROUND: Mind wandering is a common phenomenon in daily life. However, the manifestations and cognitive correlates of mind wandering in different subclinical populations remain unclear. In this study, these aspects were examined in individuals with schizotypal traits and individuals with depressive symptoms, i.e., subclinical populations of patients with schizophrenia and depression. METHODS: Forty-two individuals with schizotypal traits, 42 individuals with subclinical depression, and 42 controls were recruited to complete a mind wandering thought sampling task (state level) and a mind wandering questionnaire (trait level). Measures of rumination and cognitive functions (attention, inhibition, and working memory) were also completed by participants. RESULTS: Both subclinical groups exhibited more state and trait mind wandering than did the control group. Furthermore, individuals with schizotypal traits demonstrated more trait mind wandering than individuals with subclinical depression. Rumination, sustained attention, and working memory were associated with mind wandering. In addition, mind wandering in individuals with subclinical depression can be accounted for by rumination or attention, while mind wandering in individuals with high schizotypal traits cannot be accounted for by rumination, attention, or working memory. CONCLUSIONS: The results suggest that individuals with high schizotypal traits and subclinical depression have different patterns of mind wandering and mechanisms. These findings have implications for understanding the unique profile of mind wandering in subclinical individuals.

Atypical semantic cognition in schizotypal personality disorder and borderline personality disorder.

Increased schizotypal traits have previously been associated with atypical semantic cognition in community samples. However, no study has yet examined whether adults diagnosed with schizotypal personality disorder (SPD) display atypical semantic fluency and memory. We hypothesized that 24 adults diagnosed with SPD would name more idiosyncratic words on the semantic fluency task and show decreased semantic recall for animal and fruit category words compared with 29 participants with borderline personality disorder (BPD) and a community sample of 96 age-matched controls. We examined whether atypical semantic cognition was specifically associated with disorganized and eccentric speech and thinking, or more broadly with pathological personality traits and personality functioning. Our main hypothesis was confirmed, as the SPD participants named more idiosyncratic words and recalled fewer semantically related words compared with controls. Surprisingly, participants with BPD likewise named more atypical words compared with controls. More idiosyncratic semantic fluency was associated with more eccentric speech and thinking. Increased idiosyncratic semantic fluency and reduced semantic recall were both coupled to increased detachment and lowered personality functioning, while reduced semantic recall further was related to increased interpersonal problems. Our findings suggest that persons with SPD, and to a lesser degree BPD, show atypical semantic cognition, which is associated with eccentric speech and thinking, and more broadly with impaired personality function, social withdrawal, and emotional flatness. The idiosyncratic semantic cognition may worsen difficulties with social reciprocity seen in SPD and BPD.

The Future-oriented Repetitive Thought (FoRT) scale: Validation in Chinese samples and application in the schizophrenia spectrum.

BACKGROUND: Repetitive thoughts are usually associated with psychopathology. The Future-oriented Repetitive Thought (FoRT) Scale is a measure designed to capture frequency of repetitive thought about positive and negative future events. However, the validity of the scale in Chinese population and its application in the schizophrenia spectrum have not been examined. METHODS: The current study aimed to examine the psychometric properties of the Chinese version of the FoRT scale and to apply it to the schizophrenia spectrum. In Study 1, three samples (total N = 1875) of university students were recruited for exploratory factor analysis, confirmatory factor analysis, and validity test, respectively. In Study 2, we identified subsamples with high schizotypal traits (N = 89) and low schizotypal traits (N = 89), and recruited 36 inpatients with schizophrenia and 41 matched healthy controls. RESULTS: The three-factor (pessimistic repetitive future thinking, repetitive thinking about future goals, and positive indulging about the future) structure of the FoRT scale with one item deleted, fitted the Chinese samples. And the scale could distinguish patients with schizophrenia and individuals with high schizotypal traits from controls. CONCLUSION: These findings support that the Chinese version of the FoRT scale is a valid tool and provide evidence for the potential applications in the schizophrenia spectrum.

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.

The MATRICS consensus cognitive battery for the assessment of cognitive impairment in schizotypal personality disorder.

Cognitive deficits are a core impairment across the range of schizophrenia (SZ) spectrum disorders, including schizotypal personality disorder (SPD). The MATRICS Consensus Cognitive Battery (MCCB) was developed to be a robust, specific, and valid cognitive assessment battery to assess cognition in clinical trials for treating cognitive impairments in SZ. Despite the similarity of cognitive impairments shown in SPD and SZ and the clear relevance of uniform assessment across a diagnostic spectrum, the MCCB has yet to be validated in SPD. As such, this is the first study to evaluate the sensitivity of the MCCB for the assessment of cognitive function in individuals with SPD. Participants were 30 individuals with SPD and 54 healthy controls (HC) assessed with the MCCB and supplemental neurocognitive assessments (Trails B, DOT test, Paced Auditory Serial Addition Test (PASAT), AX Continuous Performance Task (AX-CPT), and N-back). Individuals with SPD performed worse than HC participants on all MCCB subtests, as well as on converging supplemental tasks including Trails B, DOT test, PASAT, AX-CPT, and N-back. These results indicate that the MCCB was sensitive to cognitive impairment in SPD compared to controls. SPD participants demonstrate impairments similar to data of SZ participants within the literature, although to a slightly lesser degree of severity. Taken together, these results highlight the generalizability of using the MCCB across SZ spectrum diagnostic groups to assess cognition. Such findings allow for further comparison across disorders, greater understanding of the cognitive characteristics in the spectrum, and use of uniform assessment within cognitive intervention research.

Exploring phenotypic overlap across schizotypy and autism spectrum conditions in American and Chinese young adults.

Competing theories have been proposed to explain the considerable overlap in social-cognitive features and risk factors across schizotypy and autism spectrum conditions (ASCs). Six previous factor analyses have been reported in the literature, yet all have major limitations; evidence for the clear superiority of any of the competing theories is insufficient and warrants further investigation. The primary aim of the present research was to identify dimensions that cut across schizotypy and ASCs while addressing limitations of past research. Data were collected from three independent samples (n = 1006, 544, and 2469) in the U.S. and China using the Autism-Spectrum Quotient, the Schizotypal Personality Questionnaire, and the Wisconsin Schizotypy Scales. Exploratory factor analyses in Sample 1 identified an interpretable three-factor structure, which was replicated in Samples 2 and 3 using confirmatory factor analyses. We found consistent evidence for three dimensions (Aberrant Salience, Asociality, and Concrete Thinking) underlying schizotypy and ASCs. This three-dimension model is consistent with a common vulnerability model of schizotypy and ASCs. Implications of these findings for the schizotypy and ASCs literature are discussed.

Is P3 amplitude associated with greater gaze distraction effect in schizotypy?

A recently proposed "Hyperfocusing hypothesis" suggests that schizotypy is associated with a more narrow but more intense way of allocating attention. The current study aims to test a vital prediction of this hypothesis in a social context, that schizotypy may be related to greater difficulty overcoming the distracting effects of gaze. This could cause a longer time to respond to targets that are invalidly cued by gaze. The current study tested this prediction in a modified Posner cueing paradigm by using P3 as an indicator for attentional resources. Seventy-four young healthy individuals with different levels of schizotypy were included, they were asked to detect the location of a target that was cued validly or invalidly by the gaze and head orientation. The results revealed that (a) schizotypy is associated with hyperfocusing on gaze direction, leading to greater difficulty overcoming the distracting effect of gaze. The higher the trait-schizotypy score, the more time needed to respond to targets that were invalidly cued by gaze (b) schizotypy is associated with reduced P3 which is directed by social communicative stimuli. The higher the trait-schizotypy score, the smaller the amplitude of P3 (c) the relationship between schizotypal traits and response times of the gaze-invalid condition is fully intermediated by P3. The findings of the current study suggest the P3 component may be a crucial neural mechanism underlying joint attention deficits in schizophrenia.

The positive dimension of schizotypy is associated with self-report measures of autobiographical memory and future thinking but not experimenter-scored indices.

ABSTRACTThe ability to remember our past and to imagine the future are critical to our sense of self. Previous research has indicated that they are disrupted in schizophrenia. However, it is unclear (i) whether this is found when examining experimenter-scored indices of content and/or participants' self-report of phenomenological characteristics, and (ii) how these abilities might be related to symptoms. This study sought to address these questions by taking a dimensional approach and measuring positive and negative schizotypal experiences in healthy people (n = 90). Participants were given cue words. For some, they remembered an event from the past and for others they generated an event in the future. No significant relationships were found with any aspect of schizotypy when participants' descriptions were scored by the experimenter according to a standardised episodic content measure. In contrast, several significant positive correlations were observed for past memory and future thinking when examining the positive dimension of schizotypy and participants' ratings, particularly to sensory characteristics of the experience and mental pre- or reliving. These results indicate enhanced subjective experiences of autobiographical memory and future thinking in those who report delusional and hallucinatory-like occurrences, which might be linked to mental imagery or metacognitive alterations.

Towards a scalable approach to assess speech organization across the psychosis-spectrum -online assessment in conjunction with automated transcription and extraction of speech measures.

Automatically extracted measures of speech constitute a promising marker of psychosis as disorganized speech is associated with psychotic symptoms and predictive of psychosis-onset. The potential of speech markers is, however, hampered by (i) lengthy assessments in laboratory settings and (ii) manual transcriptions. We investigated whether a short, scalable data collection (online) and processing (automated transcription) procedure would provide data of sufficient quality to extract previously validated speech measures. To evaluate the fit of our approach for purpose, we assessed speech in relation to psychotic-like experiences in the general population. Participants completed an 8-minute-long speech task online. Sample 1 included measures of psychometric schizotypy and delusional ideation (N = 446). Sample 2 included a low and high psychometric schizotypy group (N = 144). Recordings were transcribed both automatically and manually, and connectivity, semantic, and syntactic speech measures were extracted for both types of transcripts. 73%/86% participants in sample 1/2 completed the experiment. Nineteen out of 25 speech measures were strongly (r > 0.7) and significantly correlated between automated and manual transcripts in both samples. Amongst the 14 connectivity measures, 11 showed a significant relationship with delusional ideation. For the semantic and syntactic measures, On Topic score and the Frequency of personal pronouns were negatively correlated with both schizotypy and delusional ideation. Combined with demographic information, the speech markers could explain 11-14% of the variation of delusional ideation and schizotypy in Sample 1 and could discriminate between high-low schizotypy with high accuracy (0.72-0.70, AUC = 0.78-0.79) in Sample 2. The moderate to high retention rate, strong correlation of speech measures across manual and automated transcripts and sensitivity to psychotic-like experiences provides initial evidence that online collected speech in combination with automatic transcription is a feasible approach to increase accessibility and scalability of speech-based assessment of psychosis.

Quantifying the effects of practicing a semantic task according to subclinical schizotypy.

The learning ability of individuals within the schizophrenia spectrum is crucial for their psychosocial rehabilitation. When selecting a treatment, it is thus essential to consider the impact of medications on practice effects, an important type of learning ability. To achieve this end goal, a pre-treatment test has to be developed and tested in healthy participants first. This is the aim of the current work, which takes advantage of the schizotypal traits present in these participants to preliminary assess the test's validity for use among patients. In this study, 47 healthy participants completed the Schizotypal Personality Questionnaire (SPQ) and performed a semantic categorization task twice, with a 1.5-hour gap between sessions. Practice was found to reduce reaction times (RTs) in both low- and high-SPQ scorers. Additionally, practice decreased the amplitudes of the N400 event-related brain potentials elicited by semantically matching words in low SPQ scorers only, which shows the sensitivity of the task to schizotypy. Across the two sessions, both RTs and N400 amplitudes had good test-retest reliability. This task could thus be a valuable tool. Ongoing studies are currently evaluating the impact of fully deceptive placebos and of real antipsychotic medications on these practice effects. This round of research should subsequently assist psychiatrists in making informed decisions about selecting the most suitable medication for the psychosocial rehabilitation of a patient.

Moral learning and positive schizotypy: Social cognitive mechanisms in psychosis- proneness.

BACKGROUND: Delusional thoughts such as paranoia and conspiratorial thinking reflect beliefs in others' intentions to do harm. Given the integral role of harm evaluation in moral cognition, a better understanding of how psychosis-prone individuals process others' moral characters may provide insights into social cognitive mechanisms of these types of delusions. METHODS: An online sample of 293 participants was drawn from the general population, using Amazon Mechanical Turk. Participants performed a moral inference task, where they predicted and judged the binary choices of two fictitious agents ("good" or "bad") to impose harm under different levels of financial incentives. An investment game involving the same agents then examined participants' trust behavior. Psychosis-proneness was measured with the Multidimensional Schizotypy Scale Brief Edition. RESULTS: A set of multiple regressions showed that positive schizotypy was associated with a lower yet more confident pre-experimental expectation of the agent's moral character, lower prediction accuracy of the agent's harm preferences, less belief revision, and undifferentiated perception of the good and bad agents' characters. Positive schizotypy was also related to higher expectations for reciprocity in the investment game, regardless of agent characters. CONCLUSION: Our findings suggest that inflexible beliefs associated with psychosis-proneness extend beyond negative prior expectations, also reflecting difficulties in moral learning. The resulting undifferentiated moral impressions might contribute to undue suspicion of benevolent individuals and increased gullibility to malicious ones, potentially further strengthening conspiratorial beliefs.

Schizotypy and perceptual span in a non-clinical sample: a virtual reality study.

INTRODUCTION: Individuals with high schizotypy or schizophrenia exhibit difficulties in distributing their attention across space, leading to a reduction in their "perceptual span" - the extent of visual space that can be attended to at once. In this study, we aim to explore the correlation between schizotypy and perceptual span in a non-clinical sample to investigate whether perceptual span correlates with schizotypy across its range. METHODS: Schizotypy was assessed in fifty-five participants using the Schizotypy Personality Questionnaire (SPQ; Raine, 1991). Participants were required to attend to two dynamic targets displayed in a head-mounted virtual reality display. Perceptual span was estimated as the lateral angle of separation between the two targets beyond which performance in the task dropped to threshold. RESULTS: Participants with higher schizotypy scores performed significantly worse on the task. Of all the factors associated with schizotypy, the shared variance between Disorganisation and Cognitive/Perceptual Factors was most predictive of task performance. CONCLUSION: The results support the hypothesis that schizotypy predicts perceptual span in non-clinical samples. Furthermore, the demonstration of a reduced perceptual span in individuals with higher trait schizotypy shows that variations in an individual's capacity to divide attention across space can be accurately captured using a virtual reality head-mounted display.

Variation of subclinical psychosis across 16 sites in Europe and Brazil: findings from the multi-national EU-GEI study.

BACKGROUND: Incidence of first-episode psychosis (FEP) varies substantially across geographic regions. Phenotypes of subclinical psychosis (SP), such as psychotic-like experiences (PLEs) and schizotypy, present several similarities with psychosis. We aimed to examine whether SP measures varied across different sites and whether this variation was comparable with FEP incidence within the same areas. We further examined contribution of environmental and genetic factors to SP. METHODS: We used data from 1497 controls recruited in 16 different sites across 6 countries. Factor scores for several psychopathological dimensions of schizotypy and PLEs were obtained using multidimensional item response theory models. Variation of these scores was assessed using multi-level regression analysis to estimate individual and between-sites variance adjusting for age, sex, education, migrant, employment and relational status, childhood adversity, and cannabis use. In the final model we added local FEP incidence as a second-level variable. Association with genetic liability was examined separately. RESULTS: Schizotypy showed a large between-sites variation with up to 15% of variance attributable to site-level characteristics. Adding local FEP incidence to the model considerably reduced the between-sites unexplained schizotypy variance. PLEs did not show as much variation. Overall, SP was associated with younger age, migrant, unmarried, unemployed and less educated individuals, cannabis use, and childhood adversity. Both phenotypes were associated with genetic liability to schizophrenia. CONCLUSIONS: Schizotypy showed substantial between-sites variation, being more represented in areas where FEP incidence is higher. This supports the hypothesis that shared contextual factors shape the between-sites variation of psychosis across the spectrum.

The role of the differential outcomes procedure and schizotypy in the recognition of dynamic facial expressions of emotions.

Emotional facial expression recognition is a key ability for adequate social functioning. The current study aims to test if the differential outcomes procedure (DOP) may improve the recognition of dynamic facial expressions of emotions and to further explore whether schizotypal personality traits may have any effect on performance. 183 undergraduate students completed a task where a face morphed from a neutral expression to one of the six basic emotions at full intensity over 10 s. Participants had to press spacebar as soon as they identified the emotion and choose which had appeared. In the first block, participants received no outcomes. In the second block, a group received specific outcomes associated to each emotion (DOP group), while another group received non-differential outcomes after correctly responding (NOP group). Employing generalized linear models (GLMs) and Bayesian inference we estimated different parameters to answer our research goals. Schizotypal personality traits did not seem to affect dynamic emotional facial expression recognition. Participants of the DOP group were less likely to respond incorrectly to faces showing Fear and Surprise at fewer intensity levels. This may suggest that the DOP could lead to better identification of the main features that differentiate each facial expression of emotion.

Can you believe your eyes? Positive schizotypy is associated with increased susceptibility to the Müller-Lyer illusion.

BACKGROUND AND HYPOTHESIS: Visual illusions provide a unique opportunity to understand cognitive and perceptual alterations in schizophrenia-spectrum conditions. Schizophrenia patients often exhibit increased susceptibility to the Müller-Lyer illusion. Here, we investigate susceptibility to the Müller-Lyer visual illusion in the general population with different levels of schizotypy. STUDY DESIGN: We assessed a population-based convenience sample (N = 263) on an online platform. In addition to basic demographics, participants completed the Müller-Lyer illusion, the Cardiff Anomalous Perceptions Scale (CAPS) to measure perceptual anomalies, and the Multidimensional Schizotypy Scale - Brief (MSS-B) for schizotypic traits. To evaluate what predicts susceptibility to the illusion, we fitted a large set of multilevel logistic regression models and performed model averaging over the coefficients. STUDY RESULTS: We found support for increased illusion susceptibility among individuals with high positive schizotypy. However, we did not find a comparable effect for anomalous perceptions alone, or for negative or disorganized schizotypy. CONCLUSIONS: The increased Müller-Lyer effect in positive schizotypy might be specific to delusion-like beliefs and magical ideation. Further research is needed to clarify how a hierarchical Bayesian formulation of brain function (e.g. imbalances between bottom-up perceptual processing and substantial reliance on prior expectations) can account for the Müller-Lyer effect in schizophrenia-spectrum conditions.

Co-occurrence of borderline and schizotypal personality disorders: a scoping review.

BACKGROUND: The historical concept of borderline conditions refers to the pathology on the border between neurosis and psychosis. In DSM-III the conditions were divided into specific but also somewhat overlapping diagnostic criteria for Borderline Personality Disorder (BPD) and Schizotypal Personality Disorder (SPD). This phenomenological overlap, which results in co-occurrence of the two diagnoses, remains a clinical challenge to this day. METHODS: To address this issue we examined the co-occurrence of SPD and BPD according to the established DSM-IV/-5 diagnostic criteria. A literature search was conducted including studies that employed a structured interview with defined BPD and SPD criteria. RESULTS: Studies from 20 samples were included (i.e. 15 patients, 3 community and 2 forensic samples). For patients diagnosed primarily with BPD, 1-27% also met the criteria for SPD and for patients diagnosed primarily with SPD, 5 - 33% showed co-occurrence with BPD. In the forensic samples, co-occurrence for primary BPD was 10% and 67 - 82% for primary SPD. In the community samples, co-occurrence for primary BPD was 29% and 50% for primary SPD. The pattern of co-occurrence across community samples was particularly heterogeneous. CONCLUSION: The identified co-occurrences for BPD and SPD were considerably sample-dependent, and samples and measurements were generally too heterogeneous for a precise meta-analysis. Forensic and community samples generally showed higher co-occurrences, but these findings were characterized by potential methodological limitations.

Schizotypy Moderates the Relationship Between Sleep Quality and Social Cognition.

ABSTRACT: Poor sleep quality has been tied to worse social cognition. Social cognitive deficits have been noted in those with high schizotypy. Yet, no study has assessed whether schizotypy moderates the relationship between sleep quality and social cognition, which may be vital to our understanding of contributors to social functioning. We conducted a cross-sectional analysis of associations of sleep quality and social cognition, with potential moderation by schizotypy. Participants ( n = 906) completed self-report measures of schizotypy, sleep quality, and social cognition. Levels of schizotypy significantly moderated some of the relationships between sleep and social cognition. For participants low in total or interpersonal schizotypy, worse sleep quality was associated with worse theory of mind scores. For participants low in total, disorganized, or cognitive perceptual schizotypy, worse sleep quality was associated with worse self-reported cognitive empathy. For those high in these facets of schizotypy, worse sleep quality was associated with better self-reported cognitive empathy. These results suggest that the individual facets of schizotypy provide additional information and, therefore, are important to assess when examining social cognition and sleep.

Childhood trauma moderates schizotypy-related brain morphology: analyses of 1182 healthy individuals from the ENIGMA schizotypy working group.

BACKGROUND: Schizotypy represents an index of psychosis-proneness in the general population, often associated with childhood trauma exposure. Both schizotypy and childhood trauma are linked to structural brain alterations, and it is possible that trauma exposure moderates the extent of brain morphological differences associated with schizotypy. METHODS: We addressed this question using data from a total of 1182 healthy adults (age range: 18-65 years old, 647 females/535 males), pooled from nine sites worldwide, contributing to the Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Schizotypy working group. All participants completed both the Schizotypal Personality Questionnaire Brief version (SPQ-B), and the Childhood Trauma Questionnaire (CTQ), and underwent a 3D T1-weighted brain MRI scan from which regional indices of subcortical gray matter volume and cortical thickness were determined. RESULTS: A series of multiple linear regressions revealed that differences in cortical thickness in four regions-of-interest were significantly associated with interactions between schizotypy and trauma; subsequent moderation analyses indicated that increasing levels of schizotypy were associated with thicker left caudal anterior cingulate gyrus, right middle temporal gyrus and insula, and thinner left caudal middle frontal gyrus, in people exposed to higher (but not low or average) levels of childhood trauma. This was found in the context of morphological changes directly associated with increasing levels of schizotypy or increasing levels of childhood trauma exposure. CONCLUSIONS: These results suggest that alterations in brain regions critical for higher cognitive and integrative processes that are associated with schizotypy may be enhanced in individuals exposed to high levels of trauma.