Factor Structure and Measurement Invariance of the Wisconsin Schizotypy Scales across Gender and Age

Environmental and psychopathological predictors of clinical high-risk of psychosis in adolescence

OBJECTIVES

Clinical high-risk of psychosis (CHRp) samples can be heterogeneous, consisting essentially of people with not only psychotic-like experiences but also nonspecific symptoms that may reflect common mental disorders such as depression, anxiety, or substance abuse pathologies. Few studies have attempted to analyze and understand psychosis risk in relation to both environmental (ER) and psychopathological risk (PsR) factors. This study aimed to determine the clinical risk of psychosis in adolescents.

METHODS

A representative sample of 1824 Spanish adolescents from the general population was evaluated using different scales to thoroughly examine the possible interaction of CHRp with various ER and PsR factors. Partial correlations were calculated to assess the relationships between the variables. A series of hierarchical linear regression models were then used to obtain a CHRp predictor model.

RESULTS

The CHRp predictor model indicated that PsR was the most significant determining factor, explaining 22% of the total associated variance of CHRp. However, the ER factor also emerged as a significant predictor of high-risk psychosis (accounting for 9% of the variance).

CONCLUSIONS

A predictive model for CHRp in adolescents was found, in which common psychological problems were presented as more determinant risk factors than ER disruptors. Furthermore, certain transdiagnostic processes, such as psychological inflexibility, may play a central role in the development of mental health problems, including psychosis. Specifying the mechanisms underlying the emergence of CHRp in adolescence is the key to optimizing the focus of preventive therapeutic interventions in these early stages.

Does childhood trauma predict schizotypal traits? A path modelling approach in a cohort of help-seeking subjects

Schizotypy constitutes a susceptibility to beneficial and deleterious schizotypal traits, ranging from coping mechanisms to schizotypal personality disorder on a psychosis continuum. Growing evidence indicates a relationship between childhood adversity and trauma and schizotypy. However, the exact influence of childhood adversity and trauma on schizotypy and its relation to sex is not sufficiently understood. Therefore, we investigated sex-adjusted connections between childhood adversity and trauma subdomains (emotional/physical/sexual abuse, emotional/physical neglect) and positive (magical ideation, perceptual aberration) as well as negative schizotypy (physical/social anhedonia). In total, 240 outpatients of the Early Detection and Intervention Centre of the University Hospital Cologne were assessed with the Trauma and Distress Scale for childhood adversity and trauma and the Wisconsin Schizotypy Scales for schizotypy. Path analyses were performed to investigate sex-adjusted correlations. The well-fitting path model of the total sample linked emotional abuse to magical ideation (p = 0.03; SE = 0.20) and emotional neglect to social anhedonia (p = 0.01; SE = 0.26). In females, physical abuse predicted magical ideation (p = 0.01; SE = 0.33), while emotional neglect forecasted physical anhedonia (p = 0.03; SE = 0.34) and social anhedonia (p = 0.03; SE = 0.32). In males, sexual abuse predicted perceptive aberration (p = 0.04; SE = 0.19) and emotional abuse forecasted magical ideation (p = 0.03; SE = 0.27). Overall, the significance of sex-specific interrelations between trauma and schizotypy were highlighted. Magical ideation and perceptive aberration occurred prominently in the absence of negative and disorganized schizotypy, thus positive schizotypy could be discussed as a beneficial expression of coping with emotional, physical and sexual abuse. Furthermore, emotional neglect should be addressed particularly to prevent deleterious negative schizotypy in females.Trial registration number (20-1243), date of registration (May 19th 2020), retrospectively registered.

A novel construct of anhedonia revealed in a Chinese sample via the Revised Physical and Social Anhedonia Scales

BACKGROUND

Anhedonia is a core clinical symptom of mental disorders. The Revised Physical Anhedonia Scale (RPAS) and the Revised Social Anhedonia Scale (RSAS) have been applied in clinical and non-clinical samples since 1980s. However, the construct of a unified RPAS&RSAS for comprehensive measurement of anhedonia has never been explored. Therefore, the purpose of our study was to examine the factor structure of the unified RPAS&RSAS among undergraduates and clinical patients.

METHODS

A total of 3435 undergraduates from two universities and 294 clinical patients with mental disorders had completed the Chinese version of the RPAS and the RSAS. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were each conducted to reveal the constructs of the RPAS and the RSAS. CFA was used to evaluate first- and second-order models for the unified RPAS&RSAS in undergraduates and clinical patients. The internal consistency and test-retest reliability of the RPAS and the RSAS were also evaluated.

RESULTS

EFA and CFA indicated 2-factor structures for RPAS and RSAS, with the factors being defined as anticipatory anhedonia and consummatory anhedonia. The second-order model of the unified RPAS&RSAS in the undergraduates and clinical patients both had satisfactory fit index values (Undergraduate sample: CFI = 0.901, TLI = 0.899, RMSEA = 0.055, SRMR = 0.086; Clinical sample: CFI = 0.922, TLI = 0.911, RMSEA = 0.052, SRMR = 0.078). The psychometric robustness of the RPAS&RSAS were confirmed by high internal consistency and test-retest reliability values.

CONCLUSIONS

The unified RPAS&RSAS with a second-order structure was confirmed in both undergraduates and clinical samples in Chinese. The construct of anhedonia was refreshed as covering physical and social domains, and each of them includes both anticipatory and consummatory components.

The interrelationship between schizotypy, clinical high risk for psychosis and related symptoms: Cognitive disturbances matter

Schizotypy and clinical high risk (CHR) criteria can identify individuals who are at increased risk for developing psychosis in community and patient samples. However, both approaches have rarely been combined, and very little is known about their associations. Therefore, we examined the factorial structure of CHR and related symptoms and schizotypy features as well as their interrelationship for the first time in a comprehensive approach. In a sample of 277 patients (22 ± 6 years) from two early detection services, structural equation modeling including confirmatory factor analysis was performed to test a theory-driven model using four Wisconsin Schizotypy Scales, 14 predictive basic symptoms (BS) of the Schizophrenia Proneness Instrument, and positive, negative, and disorganized symptoms from the Structured Interview for Psychosis-Risk Syndromes. The data fitted well to the six hypothesized latent factors consisting of negative schizotypy, positive schizotypy including perceptual BS, negative symptoms, positive symptoms, disorganized symptoms and cognitive disturbances. As postulated, schizotypy features were significantly associated with positive, negative and disorganized symptoms through cognitive disturbances. Additionally, positive and negative schizotypy also had a direct association with the respective symptom-domain. While the identified factorial structure corresponds well to dimensional models of schizotypy and psychoses, our model extends earlier models by indicating that schizotypy features are associated with positive, negative and disorganized symptoms directly or indirectly via subjective cognitive disturbances. This calls for more attention to subjective cognitive deficits in combination with heightened schizotypy in the early detection and intervention of psychoses - or even of an Attenuated Psychosis Syndrome.

The factor structure of the short form of the Wisconsin schizotypy scales

The Chapman psychosis-proneness scales-also known as Wisconsin schizotypy scales (WSS)-are among the most used tools to measure schizotypy. The factor structure of the short-form WSS was investigated in a mixed sample of patients with chronic mental disorders and of healthy subjects from the general population. One hundred patients with a chronic mental disorder were enrolled over a 6-month period. For each patient, two controls of same sex and similar age (±5 years) were enrolled; 131 accepted to take part in the study. The unidimensional, the correlated four-factor, the second-order two-factor models, and the bifactor model with two or four orthogonally independent factors of the short-form WSS were tested with confirmatory factor analysis. Good reliability of the short-form WSS was confirmed, as its capacity of differentiating people with and without schizotypy. The bifactor models were superior to other models. However, in both bifactor models the explained common variance (ECV) attributable to the general factor and the percentage of uncontaminated correlations (PUC) were too low to use a general summary score as a measure of a single latent schizotypy variable. Symptoms scores derived from the short-form WSS can be better appreciated within a multidimensional model of schizotypy.

Normative data of the Magical Ideation Scale from childhood to adulthood in an Italian cohort

The assessment of schizotypy allows to identify people at risk to develop psychosis. For this purpose, psychometric tools have been developed, such as the Magical Ideation Scale (MIS). This scale investigates attenuated forms of thought transmission experiences, thought withdrawal and aberrant beliefs, related to positive schizotypy. This study aims at providing an Italian version of the MIS and its normative data in the general population from childhood to adulthood, being the first study evaluating subjects under 17year-old. The Italian MIS version was translated by three independent operators and administered to 1378 non-clinical participants, stratified into four age groups (i.e., 8-13, 14-17, 18-24 and 25-34). The unidimensionality of the scale was supported, and its internal consistency was satisfactory (i.e., ordinal Cronbach's αs ranging from 0.86 to 0.90 in different age groups), as well as test-retest reliability (i.e., 1-month ICC of 0.82 in a retested sub-sample). Normative data for the age groups were provided. Specific gender and age-related differences in MIS score were found, i.e. females scored higher than males in the 25-34 age group, which in general, as a group, scored lower than all the other age groups. This study provided evidence of reliability for the Italian version of the MIS in childhood and adolescence, for the first time, as well as in adulthood, showing specific gender and age effects in the early adult cohort.

Schizotypal personality questionnaire--brief revised (updated): An update of norms, factor structure, and item content in a large non-clinical young adult sample

This study updates and provides evidence for the dimensionality, reliability, and validity of a standard instrument for detection and measurement of schizotypy in non-clinical young adults. Schizotypy represents a set of traits on which both nonclinical and schizophrenia-spectrum populations vary meaningfully. These traits are linked to biological, cognitive, and social dimensions of serious mental illness (SMI), to clinical and subclinical variation in personal and social functioning, and to risk for SMI. Reliable and valid identification of schizotypal traits has important implications for clinical practice and research. Four consecutive independent samples of undergraduates were administered the SPQ-BR (N=2552). Confirmatory factor analyses suggested a minor item wording change improved reliability, and this Updated questionnaire was implemented for three-quarters of the sample (SPQ-BRU). A, single-order, nine-factor structure had acceptable psychometric properties. The best fitting second-order structure included four higher-order factors that distinguished Social Anxiety and Interpersonal factors. This differentiation was supported by differential relationships with treatment history. The Disorganized factor had the greatest unique relationship with personal and family treatment history. With few exceptions, factor loadings showed stability across samples. Overall, the higher-order and lower-order factors of schizotypy demonstrated reliability and convergent and discriminant validity; detailed psychometric data are presented in a supplement.

Reliability and normative data of the Perceptual Aberration Scale in an Italian juvenile general population sample

Psychometric tools, such as the Perceptual Aberration Scale (PAS), have been developed to identify people at risk to develop psychosis. This paper aims at providing an Italian version of the Perceptual Aberration Scale and its normative data for the general juvenile Italian population. The Italian version of the PAS was produced using three independent translators. It was administered to 1089 non-clinical participants, stratified into three age-groups, i.e., 8-13, 14-17 and 18-24. The Italian version of the PAS displayed good internal consistency in each age-group evaluated (i.e. Alpha Coefficients: 0.90 for the 8-13 age-group, 0.84 for the 14-17 age-group, and 0.87 for the 18-24 age-group) and the assumption of unidimensionality was corraborate. Furthermore, normative data for the three groups were collected (i.e. cut-offs: 25 for the 8-13 age-group, 21 for the 14-17 age-group and 20 for the 18-24 age-group) and an age-related difference, as the 18-24 group scored lower than the younger groups, was found. The Italian version of the PAS proved to be a reliable psychometric tool to investigate perceptual aberration during childhood, adolescence and young adulthood.

Cross-cultural invariance of the factor structure of the Schizotypal Personality Questionnaire across Spanish and American college students

The main goal of this study was to examine the cross-cultural invariance of the factor structure of the Schizotypal Personality Questionnaire (SPQ) (Raine, 1991) in two large samples of Spanish and American young adults. The final sample was made up of 2313 college students (508 men, 22%). Their mean age was 20.5 years (S.D.=3.2). The results indicated that the Stefanis et al. (2004) four-factor model yielded the best goodness-of-fit indices compared to alternative models. Moreover, the results support configural, metric, and partial measurement invariance of the covariances of the SPQ across the two samples. The finding of measurement equivalence across cultures provides essential evidence of construct validity for the schizotypy dimensions and of the cross-cultural validity of SPQ scores. The finding of comparable dimensional structures in cross-cultural samples lends further support to the continuum model of schizotypy and schizophrenia spectrum disorders. Future studies should continue to examine the validity of scores on the SPQ and other schizotypy measures and their variation or consistency across cultures.

Relationship between anticipatory, consummatory anhedonia and disorganization in schizotypy

BACKGROUND

The disorganized and negative dimensions of schizotypy are characterized by cognitive disorganization and anhedonia, respectively. The aim of the study was to investigate the relationships between these two dimensions of schizotypy by taking into account ambivalence and the distinction between consummatory and anticipatory anhedonia.

METHODS

Dimensional analysis and categorical analysis were performed on two different samples (N = 400 and 399) of university students. Self-reported scales were used to measure cognitive disorganization, anticipatory and consummatory anhedonia, and ambivalence. Dimensional analysis using confirmatory factorial analysis examined various models of disorganized and negative schizotypy and categorical analysis compared the scores on anticipatory, consummatory anhedonia and ambivalence scales between various groups of subjects presenting either disorganized schizotypy or negative schizotypy or free of schizotypy.

RESULTS

The disorganized dimension of schizotypy was characterized by schizotypal ambivalence and anticipatory anhedonia, while the negative dimension of schizotypy was characterized by anticipatory and consummatory anhedonia.

CONCLUSION

The results suggested firstly that ambivalence was not specific of disorganized schizotypy and secondly that anticipatory anhedonia was not specific of negative schizotypy.

The assessment of positive dimension of the psychosis phenotype in college students

The Wisconsin Schizotypy Scales are one of the most used measuring instruments for the assessment of psychometric risk for psychosis. The main goal of the present study was to analyze the reliability of the scores and to provide new sources of validity evidence for the brief version of the Magical Ideation Scale (MIS-B) and the Perceptual Aberration Scale (PAS-B). The final sample was comprised of a total of 1349 university students divided into two subsamples (n1=710; M=19.8 years; n2=639; M=21.2 years). Results show that both measurement instruments have adequate psychometric properties under Classical Test Theory and Item Response Theory. Internal structure analysis of MIS-B and PAS-B, through exploratory and confirmatory factor analysis, yielded an essentially one-dimensional solution. Cronbach's alpha coefficient for the total score of MIS-B ranged between 0.86 and 0.87, whereas for the PAS-B it ranged between 0.78 and 0.89. A total of 5 items showed a differential functioning for sex. The results indicate that the MIS-B and PAS-B are brief measurement instruments with adequate psychometric properties for the assessment of the positive dimension of the psychosis phenotype and could be used as screening tools in the detection of individuals at risk for psychosis in the general population.

Sex differences in magical ideation: a community-based twin study

Two questions regarding sex differences in magical ideation were investigated in this study: (1) whether there are mean-level sex differences on the Magical Ideation Scale (MIS), and (2) whether there are quantitative and/or qualitative sex differences in the genetic contributions to variation on this scale. These questions were evaluated using data obtained from a large community sample of adult Australian twins (N = 4,355) that included opposite-sex pairs. Participants completed a modified 15-item version of the MIS within a larger assessment battery. Women reported both higher means and variability on the MIS than men; this was also observed within families (in opposite-sex twin pairs). Biometric modeling indicated that the proportion of variation in MIS scores due to genetic influences (indicating quantitative sex differences) and the specific latent genetic contributions to this variation (indicating qualitative sex differences) were the same in men and women. These findings clarify the nature of sex differences in magical ideation and point to avenues for future research.

Dimensionality of the Wisconsin Schizotypy Scales--brief forms in college students

Wisconsin Schizotypy Scales are one of the most used measuring instruments for the assessment of psychometric risk for psychosis. The main goal of the present study was to analyze the internal structure of the Wisconsin Schizotypy Scales-Brief (WSS-B) forms and the reliability of the scores in a large sample of college students. The final sample was comprised by a total of 1349 students, 288 males, with a mean age of 20.48 years (SD = 2.58). The results indicated that the WSS-B scores presented adequate psychometric properties. Cronbach's alfa coefficient for total scores in WSS-B ranged from 0.86 to 0.93. Analysis of the internal structure of the WSS-B, through confirmatory factor analysis and exploratory structural equation modeling, yielded a four factor solution (Magical Ideation, Perceptual Aberration, Social Anhedonia, and Physical Anhedonia) as the most adequate. Statistically significant differences in mean scores of WSS-B by sex were found. These results provided new validity evidence of the WSS-B scores in an independent sample of nonclinical young adults. The WSS-B seems to be useful, brief, and easy to administrate for the screening of extended psychosis phenotype in the general population.

Positive and negative schizotypy are associated with prodromal and schizophrenia-spectrum symptoms

The present study examined the validity of psychometrically assessed positive and negative schizotypy in a study of 214 Spanish young adults using interview and questionnaire measures of impairment and psychopathology. Schizotypy provides a useful construct for understanding the etiology and development of schizophrenia and related disorders. Recent interview, laboratory, and experience sampling studies have supported the validity of psychometrically assessed positive and negative symptom dimensions. The present study expands on previous findings by examining the validity of these dimensions in a Spanish sample and employing a widely used interview measure of the schizophrenia prodrome. As hypothesized, the positive schizotypy dimension predicted CAARMS ultra high-risk or psychosis threshold status, and both dimensions uniquely predicted the presence of schizophrenia-spectrum personality disorders. Furthermore, positive schizotypy was associated with psychotic-like, paranoid, schizotypal, and mood symptoms, whereas negative schizotypy was associated with interview ratings of negative and schizoid symptoms. The schizotypy dimensions were also distinguished by their associations with self and other schemas. Positive schizotypy was associated with increased negative self and other schemas, whereas negative schizotypy was associated with decreased positive self and other schemas. The findings provide further construct validation of positive and negative schizotypy and support these dimensions as universal constructs.

Relationship between Schizotypal and Borderline Traits in College Students

The main objective of the present investigation was to analyze the relationship between self-reported schizotypal and borderline personality traits in a sample of 759 college students (M = 19.63 years; SD = 2.03). For this purpose, the Schizotypal Personality Questionnaire-Brief (SPQB; Raine and Benishay, 1995) and Borderline Personality Questionnaire (BPQ; Poreh et al., 2006) were administered. The results showed that schizotypal and borderline features are partially related at subclinical level. The exploratory factor analysis conducted on the subscales revealed a three-factor solution comprised of the following factors: Identity/Interpersonal, Lack of Control and Schizotypal. The canonical correlation analysis showed that schizotypal features and borderline personality traits shared 34.8 % of the variance. The data highlight the overlap between schizotypal and borderline personality traits in nonclinical young adults. Future studies should continue to examine the relationship and the degree of overlap between these traits in community samples.

Reliability and sources of validity evidence of the Oviedo Schizotypy Assessment Questionnaire-Abbreviated (ESQUIZO-Q-A)

The main goal of this research was to examine the reliability and different sources of validity evidence of the Oviedo Schizotypy Assessment Questionnaire-Abbreviated (ESQUIZO-Q-A) in nonclinical adolescents. The final sample was made up of 1,455 participants, 705 males (48.5%), with a mean age of 15.92 years (SD = 1.18). The internal consistency of the subscales ranged from .62 to .75. The analysis of its internal structure yielded a three-dimensional solution based on the dimensions: Reality Distortion, Anhedonia, and Interpersonal Disorganization. Likewise, the goodness-of-fit indices derived from the Confirmatory Factor Analysis for the hypothesized three-factor model were adequate. The three dimensions of the ESQUIZO-Q-A were significantly correlated with the subscales of the Strengths and Difficulties Questionnaire. The ESQUIZO-Q is a brief and simple self-report with adequate psychometric properties for the assessment of schizotypal traits in nonclinical adolescent populations. Future research should continue to explore the metric quality of the ESQUIZO-Q-A (e.g., sensitivity and specificity) and incorporate the new advances in psychological and educational assessment such as Computerized Adaptive Testing.

Measurement invariance of the Schizotypal Personality Questionnaire-Brief across gender and age

The purpose of this study was to examine the dimensional structure and measurement invariance of the Schizotypal Personality Questionnaire-Brief (SPQ-B) (Raine and Benishay, 1995) across sex and age in a representative sample of nonclinical adolescents and young adults. The sample consisted of 1789 adolescents and young adults (42.1% males), with a mean age of 17.1years (S.D.=2.9). The results indicated that the Likert version of the SPQ-B showed adequate psychometric properties (α total score 0.89). The schizotypal personality models that presented the best fit indices were Raine et al.'s (1994) three-factor model and Stefanis et al.'s (2004) four-factor model. In addition, the results support the measurement invariance of the SPQ-B across sex and age. When the latent means of the schizotypal dimensions were compared across sex and age, statistically significant differences were found. Consistent with previous literature, schizotypal personality is a multidimensional construct whose structure appears invariant across sex and age. Future studies should examine the invariance of schizotypal personality across cultures, as well as using the SPQ-B as a screening method in the general population to detect individuals at risk for schizophrenia-spectrum disorders, given its rapid and easy administration.