Schizotypal traits in adolescents: Links to family history of psychosis and psychological distress

Childhood Schizotypy and Adolescent Mental Disorder

BACKGROUND AND HYPOTHESIS

Schizotypy provides a framework for understanding the developmental nature of psychotic disorders and a means of identifying "at-risk" individuals early in the lifespan. However, there is a lack of prospective longitudinal research examining the relationship between schizotypy in childhood and later psychotic and other mental disorders. We hypothesized that distinct profiles of schizotypy in childhood would be differentially associated with psychotic and other mental disorders emerging later in adolescence.

STUDY DESIGN

In a large population cohort of Australian young people (n = 26 837), we prospectively examined the relationship between person-centered profiles of schizotypy identified in middle childhood (age ~11 years) and adolescent diagnoses (age ~13-18 years) across 7 types of mental disorders using multinomial logistic regression.

RESULTS

Membership in any of 3 childhood schizotypy profiles (true schizotypy, affective schizotypy, or introverted schizotypy) was associated with an increased likelihood of being diagnosed with any type of mental disorder in adolescence; effects were strongest for the true schizotypy group (aOR = 3.07, 95% CI = 2.64, 3.57), followed by the introverted (aOR = 1.94, 95% CI = 1.75, 2.15) and affective (aOR = 1.29, 95% CI = 1.13, 1.47) schizotypy groups. Six of the 7 types of mental disorders measured (including psychotic disorders) were associated with at least 1 schizotypy group.

CONCLUSIONS

Schizotypy in middle childhood is an important correlate of mental disorders in adolescence; however, it does not appear to be specifically associated with psychotic disorders in this age group.

Schizotypal traits in a large sample of high-school and university students from Tunisia: correlates and measurement invariance of the arabic schizotypal personality questionnaire across age and sex

BACKGROUND

The main goal of the present study was to examine the characteristics of schizotypal traits and their correlations with genetic (i.e., family history of mental illness), demographic (i.e., age, sex), environmental (e.g., income, urbanicity, tobacco/alcohol/cannabis use), and psychological (i.e., personal history of mental illness other than psychosis) factors in Tunisian high-school and university students. Our secondary goal was to contribute the literature by examining the factor structure and factorial invariance of the Arabic Schizotypal Personality Questionnaire (SPQ) across sex and age (adolescents [12-18 years] vs. young adults [18-35 years]) groups.

METHOD

This was a cross-sectional study involving 3166 students: 1160 (36.6%) high-school students (53.0% females, aged 14.9 ± 1.8); and 2006 (63.4%) university students (63.9% females, aged 21.8 ± 2.3). All students were asked to complete a paper-and-pencil self-administered questionnaire containing sociodemographic characteristics as well as the Arabic version of the SPQ.

RESULTS

The total sample yielded total SPQ scores of 24.1 ± 16.6 out of 74. The SPQ yielded good composite reliability as attested by McDonald's omega values ranging from .68 to .80 for all nine subscales. Confirmatory Factor Analysis indicated that fit of the 9-factor model of SPQ scores was acceptable. This model is invariant (at the configural, metric and structural levels) across sex and age. Except for "Odd or eccentric behavior", all schizotypy features were significantly higher among female students compared to males. Multivariable analyses showed that female sex, being a university student, lowest family incomes, tobacco use, and having a personal history of psychiatric illness were significantly associated with higher positive, negative and disorganized schizotypy subscales scores.

CONCLUSION

Future research still needs to confirm our findings and investigate the contribution of the identified factors in the development of clinical psychosis. We can also conclude that the Arabic SPQ is appropriate for measuring and comparing schizotypy across age and sex in clinical and research settings. These findings are highly relevant and essential for ensuring the clinical utility and applicability of the SPQ in cross-cultural research.

Developmental profiles of schizotypy in the general population: A record linkage study of Australian children aged 11-12 years

Objectives

The detection of young people at high risk for psychotic disorders has been somewhat narrowly focused on overt symptom‐based markers that reflect mild reality distortion (e.g., psychotic‐like experiences), or prodromal syndromes that are proximal to psychosis onset. The concept of schizotypy represents a broader framework for investigating risk for schizophrenia (and other disorders) in childhood, before the onset of prodromal or overt symptoms. We sought to detect profiles of risk for psychosis (schizotypy) in a general population sample of 22,137 Australian children aged 11–12 years, and to determine early life risk factors associated with these profiles from data available in linked records (registers).

Methods

Fifty‐nine self‐reported items were used as indicators of schizotypy across six broad domains; z‐scores for each domain were subjected to latent profile analyses (LPA). A series of multinomial logistic regressions was used to examine the association between resulting profile (class) membership and several childhood and parental risk factors, and the proportion of children with mental disorders among each schizotypy profile was examined.

Results

The LPA revealed three person‐centred profiles referred to as True Schizotypy (n = 1,323; 6.0%), Introverted Schizotypy (n = 4,473; 20.2%), and Affective Schizotypy (n = 4,261; 19.2%), as well as a group of children showing no risk (n = 12,080; 54.6%). Prior exposure to perinatal and familial adversities including childhood maltreatment, as well as poor early childhood development and academic functioning, was variously associated with all risk groups. There was a higher proportion of childhood mental disorder diagnoses among children in the True Schizotypy group, relative to other profiles.

Conclusion

Subtle differences in the pattern of exposures and antecedents among schizophrenia liability profiles in childhood may reflect distinct pathogenic pathways to psychotic or other mental illness.

Practitioner points

Children aged 11–12 years report characteristics of schizotypy which can be classified into three distinct profiles that may represent different pathological processes towards later mental ill‐health.

Early life exposure to perinatal and familial adversities including childhood maltreatment, early childhood developmental vulnerability, and poor academic functioning predict membership in all three childhood schizotypy profiles.

Latent liability for schizophrenia (and potentially other mental disorders) may be represented by different profiles of functioning observable in childhood.

Early life factors of schizotypal personality disorder in adolescents: A systematic review

WHAT IS KNOWN ON THE SUBJECT?: The complexity and high prevalence of schizotypal personality disorders (SPD) pose serious challenges for mental health practice in its management, and also bring severe consequences for the patients. The identification of the specific early life factors (ELFs) that confer risk to SPD has become a major focus of clinical research on schizophrenia-spectrum disorders which aligns well with the mental health nursing's responsibility in health promotion, prevention and treatment. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: Adolescents may experience certain ELFs, which contribute to the occurrence of SPD, but no systematic review has been conducted to identify ELF among them. And nursing literature addressing modifiable ELF is very limited. Two clusters of ELF and SPD in adolescents were identified: prenatal and early postnatal factors; childhood trauma and parental factors. The findings also show that more research is needed to determine the specificity and cumulative effects of ELF on the development of SPD by using rigorous and comprehensive measurements and a longitudinal design. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Mental health nurses, especially nurses in the primary care, should be aware of potentially modifiable ELFs and incorporate more comprehensive and valid instrument for assessing cumulative ELF and SPD. These findings may serve to inform possible future interventions for SPD, such as parent education and support to mitigate these risk factors.

ABSTRACT

INTRODUCTION: Schizotypal personality disorder (SPD) affects 4% of the general population in the United States. The identification of early life factors (ELFs) that confer risk to SPD in adolescents (ages 10-24 years old) has become a major focus of clinical research on schizophrenia-spectrum disorders.

AIM

This systematic review aims to determine what ELFs contribute to the onset of SPD in the adolescent population.

METHODS

A systematic search of PubMed, PsycINFO, Psychiatry online, Scopus, Web of Science, EMBASE and CINAHL databases was conducted using relevant keywords. Data were extracted using a standardized form following PRISMA guidelines.

RESULTS

Twenty-four studies met the criteria for inclusion. ELFs in the development of SPD were grouped into two important clusters: (a) prenatal and early postnatal factors; (b) childhood trauma and parental factors.

CONCLUSION

Mental health nurses, especially nurses in primary care, should be aware of potentially modifiable ELF. Longitudinal research is needed to determine the causative roles of these ELF play in the occurrence of SPD by using rigorous measurements.

IMPLICATIONS FOR PRACTICE

These findings call for awareness of the modifiable ELF for SPD and also inform possible future interventions to reduce these risks, such as parent-training or environmental enrichment programmes.

Identifying extended psychosis phenotypes at school: Associations with socio-emotional adjustment, academic, and neurocognitive outcomes

The main goal of the present study was to explore the latent structure of extended psychosis phenotypes in a representative sample of adolescents. Moreover, associations with socio-emotional adjustment, academic achievement, and neurocognition performance across the latent profiles were compared. Participants were 1506 students, 667 males (44.3%), derived from random cluster sampling. Various tools were used to measure psychosis risk, subjective well-being, academic performance, and neurocognition. Based on three psychometric indicators of psychosis risk (schizotypal traits, psychotic-like experiences, and bipolar-like experiences), four latent classes were found: non-risk, low-risk, high reality distortion experiences, and high psychosis liability. The high-risk latent groups scored significantly higher on mental health difficulties, and negative affect, and lower on positive affect and well-being, compared to the two non-risk groups. Moreover, these high-risk groups had a significantly higher number of failed academic subjects compared to the non-risk groups. In addition, no statistically significant differences in efficiency performance were found in the neurocognitive domains across the four latent profiles. This study allows us to improve the early identification of adolescents at risk of serious mental disorder in school settings in order to prevent the incidence and burden associated with these kinds of mental health problems.

Anhedonia in young people with first episode psychosis: a longitudinal study

Aim: Previous research observed deficits in pleasure experience in chronic schizophrenia, but little is known about anhedonia in early psychosis. Aim of this study is: (1) to examine anhedonia in distinct help-seeking subgroups of young people identified through the First Episode Psychosis (FEP) criteria, (2) to investigate its correlations with psychopathology in the FEP sample, and (3) to monitor longitudinally its stability in the FEP group along 1-year follow-up period.Materials and methods: All participants (137 FEP and 95 nonpsychotic psychiatric controls [i.e. non-FEP]), aged 13-35 years, completed the Comprehensive Assessment of At-Risk Mental States (CAARMS), the Schizotypal Personality Questionnaire - Brief version (SPQ-B), the Brief O-LIFE questionnaire (BOL), and the World Health Organization Quality of Life - Brief version (WHOQOL-BREF). We used two different indexes of anhedonia: CAARMS 'Anhedonia' item 4.3 and BOL 'Introvertive Anhedonia' subscale scores.Results: In comparison with non-FEP, FEP patients showed higher baseline anhedonia scores. After 1-year follow-up period, FEP individuals had a significant decrease in severity of anhedonia scores. In the FEP group, anhedonia showed significant, enduring (over time) correlations with impaired role functioning, negative symptoms, comorbid depression, poorer self-perceived quality of life and specific schizotypal personality traits (i.e. interpersonal deficits).Conclusions: Anhedonia is relevant in the early phase of psychosis and its severity is associated with functioning deterioration and a bad quality of life.

Anhedonia in adolescents at ultra-high risk (UHR) of psychosis: findings from a 1-year longitudinal study

Previous findings suggested deficits in pleasure experience in schizophrenia, but little is known in psychosis risk prodrome, especially in adolescence. Aim of this study was (1) to assess anhedonia in distinct help-seeking subgroups of adolescents identified through the ultra-high risk (UHR) criteria, (2) to explore any association of anhedonia with other psychopathological aspects in the UHR group, and (3) to monitor longitudinally the stability of anhedonia in UHR individuals across 1-year follow-up period. 123 participants (13-18 years) completed the Comprehensive Assessment of At-Risk Mental States (CAARMS), the Beck Depression Inventory-II, the Schizotypal Personality Questionnaire-Brief version, the Brief-O-LIFE questionnaire (BOL), and the Brief version of the World Health Organization Quality of Life scale (WHOQOL-BREF). Two different indexes of anhedonia were used: CAARMS "Anhedonia" item 4.3 and BOL "Introvertive Anhedonia" subscale scores. No difference in anhedonia levels between UHR and First Episode Psychosis (FEP) groups was found. UHR adolescents showed higher CAARMS and BOL anhedonia scores than non-UHR/FEP. After 1-year follow-up period, UHR adolescents had a significant decrease in severity only in CAARMS anhedonia subscores. In UHR subgroup, CAARMS anhedonia measures showed significant correlations with impaired role functioning and negative symptoms, while BOL anhedonia was significantly correlated with specific schizotypal personality traits concerning interpersonal deficits. Anhedonia is prominent in the psychosis prodrome, also in adolescence. Its severity is not statistically different from that of FEP adolescents and is related to more severe functioning impairment and a worse quality of life.

Associations between schizotypal traits and antisocial behaviours in a sub-Saharan sample

Schizophrenic symptoms have often been associated with antisocial behaviours (ASBs). Most studies have focused on violence. The association between schizophrenia and violence is often confounded by socio demographic characteristics of patients. Overemphasis on diagnosis, rather than traits, and the traditional focus on violence may have obscured associations between psychotic features and antisocial behaviour. In this study, an analogue sample (n = 604, females = 54.4%, mean age = 21.46, SD = 5.89) completed self-report measures of schizotypy and antisocial behaviours. The aim was to identify the strength of associations between different schizotypal traits/symptoms (unusual experiences, cognitive disorganisation, impulsivity & introvertive anhedonia) and different forms of antisocial behaviour (rule breaking, physical aggression & social aggression). Differential patterns of association between genders were also considered. Traits akin to positive symptoms were more strongly associated with antisocial behaviours. Impulsive non-conformity was associated with rule breaking, physical aggression and social aggression for both males and females whilst unusual experiences traits were associated with physical and social aggression in both males and females but had only a weak (gender-nonspecific) association with rule breaking. Finally, cognitive disorganisation was not associated with any class of ASB for males but was associated with physical and social aggression in females. These specific associations could inform the development of more targeted treatment approaches for specific types of ASBs in males and females.

Latent profile analysis of psychosis liability in a community-derived sample of adolescents: Links with mental health difficulties, suicidal ideation, bipolar-like experiences and psychotic-like experiences

AIM

The main goal of the present study was to explore the latent structure of schizotypy as an indicator of psychosis liability, in a community-derived sample of adolescents. Links to mental health difficulties, prosocial behaviour, suicidal ideation, bipolar-like experiences and psychotic-like experiences (PLEs) (severity and distress) were compared across schizotypy latent profiles.

METHOD

The present research included 1588 adolescents selected by a stratified random cluster sampling. The Oviedo Schizotypy Assessment Questionnaire (ESQUIZO-Q), The Paykel Suicide Scale (PSS), The Strengths and Difficulties Questionnaire (SDQ), The Prodromal Questionnaire-Brief (PQ-B), The Mood Disorder Questionnaire (MDQ), The Penn Matrix Reasoning Test (PMRT), The Family Affluence Scale-II (FAS-II), and The Oviedo Infrequency Scale (INF-OV) were used.

RESULTS

Using latent profile analysis four latent classes (LC) were identified: "Positive schizotypy" (14.1%, n = 224), "Low schizotypy" (51.9%, n = 825), "Social Disorganization schizotypy" (27.2%, n = 432), and "High schizotypy" (6.7%, n = 107). The "High schizotypy" class scored higher on several psychometric indicators of psychopathology (ie, mental health difficulties, suicide ideation, bipolar-like experiences and PLEs) relative to the other three LC.

CONCLUSION

Four groups of adolescents with different patterns of schizotypal traits and different clinical-pathological meaning were found. Deficits found across schizotypy latent profiles, resembling those found in patients with psychosis and ultra-high risk samples. The identification of homogeneous subgroups of adolescents potentially at risk for psychosis may help us in the prevention of psychotic-spectrum disorders and mental health problems.

Latent profile analysis of anxiety disorder among left-behind children in rural Southern China: a cross-sectional study

OBJECTIVES

Previous studies have used latent profile analysis (LPA) to examine rural left-behind children's anxiety. Further study is needed to identify the heterogeneous characteristics of rural left-behind children's anxiety and explore the related factors.

SETTING

A cross-sectional survey using a school-based sample was conducted in January 2018 in Qingxin district, Qingyuan city, Guangdong province.

PARTICIPANTS

1026 left-behind children (effective response rate of the questionnaire: 95.39%).

MAIN OUTCOME MEASURES

Profile latent classes (LC) and anxiety disorder.

RESULTS

The LPA identified three anxiety LC: 'low anxiety' (56.6%), 'medium anxiety' (34.8%) and 'severe anxiety' (8.6%). The multinomial logistic regression model was used to predict the relationship between personal, family, school factors and anxiety. We found that the variables directly related to lower anxiety classes included age (12-14 years), harmonious or fair relationship with classmates, no neglect, harmonious parental relationship and the duration of mother migration <6 months.

CONCLUSIONS

These findings suggested the need for careful consideration of differences in anxieties among rural left-behind children. Identifying latent subgroups may provide an empirical basis for teachers and public health practitioners to implement anxiety intervention efforts.

Differential emotional abnormalities among schizotypy clusters

Schizotypy, a multidimensional personality organization that reflects liability to develop schizophrenia-spectrum disorders, has been associated with a number of emotional abnormalities. Yet, the exact nature of any emotional abnormalities in schizotypy is relatively unclear. Using an ethnically diverse nonclinical sample (N = 2637), the present study identified homogenous clusters of individuals based on positive and negative schizotypy dimensions and explored three interrelated domains of emotion traits closely tied to functional outcomes and quality of life: affective experience, emotional awareness, and meta-level emotions. Consistent with prior research, four schizotypy clusters were obtained: low ("nonschizotypic"), high positive, high negative, and mixed (high positive and high negative). Regarding emotion correlates of schizotypy clusters, the mixed cluster was found to be the most deviant on almost all emotion traits (e.g., heightened trait negative affect, diminished emotional clarity), suggesting that the effects of positive and negative schizotypy are additive. In addition, positive and negative schizotypy clusters were associated with differential abnormalities, with the negative cluster presenting a wider range of, and more severe, impairments compared to the low cluster (e.g., reduced trait positive affect and reduced attention to positive emotion). The current study highlights the heterogeneity in emotional traits among schizotypy dimensions and the importance of studying the mixed schizotypy in terms of emotional dysfunction.

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.

A latent profile analysis of schizotypal dimensions: Associations with psychopathology and personality

The main goal of the present study was to explore the latent structure of schizotypal traits in non-clinical young adults, and compare the latent profiles in clinical and personality characteristics: mental distress, psychosis-proneness, hypomanic experiences, and anticipatory and consummatory pleasure. A large sample of college students (N =1002; mean age =21.11 years; SD =3.92) were administered the Schizotypal Personality Questionnaire-Brief Revised, the Mood Disorder Questionnaire, the short version of the Oxford-Liverpool Inventory of Feelings and Experiences, the General Health Questionnaire-12, and the Temporal Experience of Pleasure Scale. Using latent profile analysis, four latent classes (LC) were identified: "low schizotypy" (62.4%), "average schizotypy" (17.6%), "interpersonal schizotypy" (17.1%), and "high schizotypy" (2.9%). The "high schizotypy" class scored higher on most psychometric indicators of psychopathology and personality (i.e., mental distress, schizotypy, hypomanic experiences, and anticipatory and consummatory pleasure) relative to other three latent classes. The other three schizotypal latent profiles also varied in terms of these psychopathology and personality factors. The identification of homogeneous subgroups of individuals potentially at-risk for psychosis based on schizotypal latent profiles may improve early identification and prevention efforts aimed at reducing the burden associated with psychotic-spectrum disorders and mental health problems.

Classifying risk status of non-clinical adolescents using psychometric indicators for psychosis spectrum disorders

This study is an attempt to evaluate extant psychometric indicators using latent profile analysis for classifying community-derived individuals based on a set of clinical, behavioural, and personality traits considered risk markers for psychosis spectrum disorders. The present investigation included four hundred and forty-nine high-school students between the ages of 12 and 19. We used the following to assess risk: the Prodromal Questionnaire-Brief (PQ-B), Oviedo Schizotypy Assessment Questionnaire (ESQUIZO-Q), Anticipatory and Consummatory Interpersonal Pleasure Scale-Adolescent version (ACIPS-A), and General Health Questionnaire 12 (GHQ-12). Using Latent profile analysis six latent classes (LC) were identified: participants in class 1 (LC1) displayed little or no symptoms and accounted for 38.53% of the sample; class 2 (LC2), who accounted for 28.06%, also produced low mean scores across most measures though they expressed somewhat higher levels of subjective distress; LC3, a positive schizotypy group (10.24%); LC4 (13.36%), a psychosis high-risk group; LC5, a high positive and negative schizotypy group (4.45%); and LC6, a very high distress, severe clinical high-risk group, comprised 5.34% of the sample. The current research indicates that different latent classes of early individuals at risk can be empirically defined in adolescent community samples using psychometric indicators for psychosis spectrum disorders. These findings may have implications for early detection and prevention strategies in psychosis spectrum disorders.

French Validation of the O-LIFE Short Questionnaire

Abstract. The original 104-item Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) questionnaire is a validated schizotypy questionnaire distinguishing three schizotypy dimensions (Unusual experiences, Introvertive anhedonia, Cognitive disorganization). It also includes items on Impulsive nonconformity assessing traits sensitive to borderline and antisocial personality. Recently, Mason et al. (2005) published a shortened 43-item version including all sub-dimensions. The aim of this study was to validate a French version of this short form and to study the relationships between its French- and English-speaking versions. O-LIFE short data was obtained from 1,048 students from two higher education institutions in the French-speaking part of Switzerland. Results were compared with those from an English normative sample (n = 439). A series of confirmatory factor analyses showed acceptable configural and metric invariances across the two language versions. Moreover, results from the French data support the use of both four- and three-dimensional models of schizotypy and show expected correlations with other relevant self-report instruments. This French version of the O-LIFE short form is an appropriate tool to use in French-speaking environments.

Bifactor structure of the schizotypal personality questionnaire (SPQ)

The schizotypal personality questionnaire (SPQ) is used to characterize schizotypy, a complex construct helpful for the investigation of schizophrenia-related psychopathology and putative endophenotypes. The SPQ factor structure at item level has been rarely replicated and no study had tested a bifactor model of the SPQ so far. The unidimensional, the correlated, the second-order and the bifactor models of the SPQ were tested to evaluate whether the items converge into a major single factor defining the schizotypy-proneness of the participants, to be used for grouping purpose. Parallel principal component analysis (PCA) and confirmatory factor analysis (CFA) were used to determine the optimal number of factors and components in a cross-sectional, survey design involving 649 college students (males: 47%). The first-order, nine-subscale model was confirmed by CFA in the whole sample. The best evidence from parallel PCA in the training set was in favor of a two-factor model; the bifactor implementation of this model showed good fit in the subsequent CFA. Two main dimensions of positive and negative symptoms underlie schizotypy in non-clinical samples, entailing specific risk of psychosis. On a measurement level, the study provided support for the use of the total scores of the SPQ to characterize schizotypy.

The measurement invariance of schizotypy in Europe

The short version of the Oxford-Liverpool Inventory of Feelings and Experiences (sO-LIFE) is a widely used measure assessing schizotypy. There is limited information, however, on how sO-LIFE scores compare across different countries. The main goal of the present study is to test the measurement invariance of the sO-LIFE scores in a large sample of non-clinical adolescents and young adults from four European countries (UK, Switzerland, Italy, and Spain). The scores were obtained from validated versions of the sO-LIFE in their respective languages. The sample comprised 4190 participants (M=20.87 years; SD=3.71 years). The study of the internal structure, using confirmatory factor analysis, revealed that both three (i.e., positive schizotypy, cognitive disorganisation, and introvertive anhedonia) and four-factor (i.e., positive schizotypy, cognitive disorganisation, introvertive anhedonia, and impulsive nonconformity) models fitted the data moderately well. Multi-group confirmatory factor analysis showed that the three-factor model had partial strong measurement invariance across countries. Eight items were non-invariant across samples. Significant statistical differences in the mean scores of the s-OLIFE were found by country. Reliability scores, estimated with Ordinal alpha ranged from 0.75 to 0.87. Using the Item Response Theory framework, the sO-LIFE provides more accuracy information at the medium and high end of the latent trait. The current results show further evidence in support of the psychometric proprieties of the sO-LIFE, provide new information about the cross-cultural equivalence of schizotypy and support the use of this measure to screen for psychotic-like features and liability to psychosis in general population samples from different European countries.

The stability of schizotypy across time and instruments

Little is known about the stability of schizotypy across relatively long time periods and instrumentation. This study assesses the degree of stability between schizotypy and its three factor structure as assessed by the Survey of Attitudes and Experiences (SAE) at age 17, and the Schizotypal Personality Questionnaire (SPQ) at age 23. A sample of 678 at ages 17 and 23 years from a birth cohort in Mauritius were split into two random samples, with initial analyses on the first sample independently replicated on the second sample. Cognitive-perceptual, interpersonal, and disorganized factors at age 17 correlated from 0.28 to 0.32 with their respective factors at age 23. Total scores correlated 0.41 (d=0.90) across this six year time period and increased to 0.58 (d=1.42) after correcting for measurement error. Receiver operating characteristic (ROC) analyses showed an area under the curve value of 0.74, confirmed prediction over time. Findings on predictive validity were closely replicated in the second independent sample. In contrast, social anhedonia at age 17 was unrelated to interpersonal deficits at age 23. Results provide replicable support for the moderate stability of cognitive-perceptual, interpersonal, and disorganized schizotypy across time, instrumentation, and a period of rapid developmental change.

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.

The independence of schizotypy from affective temperaments--a combined confirmatory factor analysis of SPQ and the short TEMPS-A

Sparse evidence of a co-aggregation of the risk of schizophrenia and bipolar disorder provides support for a shared but nonspecific genetic etiology of bipolar disorder and schizophrenia. Temperaments are conceptualized as trait sub-syndromic conditions of major pathologies. This study set out to test the hypothesis of a continuum between schizotypy and affective temperaments versus the alternative hypothesis of their independence based on a cross-sectional, survey design involving 649 (males: 47%) college students. The short 39-item TEMPS-A and the SPQ were used as measures of the affective temperaments and of schizotypy, respectively. Confirmatory factor analyses were applied to a unidimensional model, to a standard correlate traits model, to second-order representations of a common latent structure, and to a bifactor model. Confirmatory bifactor modeling provided evidence against a complete independence of the dimensions subsumed by the affective and the schizotypal traits. The best solution distinguished between two sub-domains grouping positive symptoms and negative symptoms as measured by the SPQ subscales, and a sub-domain related to the affective temperaments as measured by the TEMPS-A. Limitations due to the use of subscales from two different tools should be taken into account.

Schizotypal personality questionnaire: new sources of validity evidence in college students

Schizotypal traits represent the behavioral expression of vulnerability to psychosis in general population. Among the most widely used measurement instruments, we could find the Schizotypal Personality Questionnaire (SPQ) (Raine, 1991). However, some aspects of its psychometric quality have yet to be analyzed. The main goal of the present study was to gather new sources of validity evidence of the SPQ scores in non-clinical young adults. The final sample was made up of 1123 college students (M=20.3 years; S.D.=2.6). The study of the internal structure using exploratory factor analysis revealed that SPQ items were grouped in a theoretical structure of seven second-order factors. Confirmatory factor analyses showed that the four-factor model (Paranoid) displayed better goodness-of-fit indices than the other hypothetical dimensional models tested. More complex measurement models, such as those tested using second-order confirmatory factor analyses and Exploratory Structural Equation Modeling, also showed adequate goodness-of-fit indices. The reliability of the SPQ scores ranged from 0.80 to 0.91. A total of 11 items showed differential functioning by gender. Advances in psychosis phenotype measurement open up new horizons to understand the structure and content of schizotypy.

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.

A latent profile analysis of schizotypy, temperament and character in a nonclinical population: association with neurocognition

Schizotypy is conceptualized as a latent personality construct that confers liability for schizophrenia, while it is also suggested that schizotypy can relate to certain favorable aspects. Investigating individual-level interactions between schizotypy and broader personality characteristics might give a clue to this question. We aimed to identify homogeneous classes of individuals based on schizotypy, temperament and character and to validate this classification using comprehensive neurocognitive data. We studied 455 nonclinical adults using the Schizotypal Personality Questionnaire, the Temperament and Character Inventory, and an array of neuropsychological tests. A latent profile analysis (LPA) of schizotypy, temperament and character was conducted, and cognitive performance was compared as a function of latent class membership. LPA provided a 3-class solution. Of the sample, 15% was classified into a "high-positive-schizotypy/adaptive" group characterized by high cognitive-perceptual but low interpersonal schizotypy, together with low harm avoidance and high self-directedness, cooperativeness and self-transcendence; 18% was classified into a "high-schizotypy/maladaptive" group characterized by overall high schizotypy, together with high harm avoidance and low self-directedness and cooperativeness; and 67% was classified into a "low-schizotypy/adaptive" group characterized by overall low schizotypy, together with intermediate-to-low harm avoidance, high self-directedness and intermediate-to-high cooperativeness. Overall cognitive performance of the high-positive-schizotypy/adaptive group was comparable to that of the low-schizotypy/adaptive group and superior to that of the high-schizotypy/maladaptive group. The present LPA clearly defines a group of individuals who have adaptive personality traits and intact neuropsychological functions despite high positive schizotypy, suggesting that there may be complex, nonlinear relationships between schizotypal traits and psychopathology.

Latent profile analysis of healthy schizotypy within the extended psychosis phenotype

Converging evidence suggests that psychosis exists on a continuum, and that even mentally "healthy" individuals may experience subclinical psychotic experiences. However, little research has examined the subjective and psychological well-being of individuals in the putatively healthy end of the continuum. This study explored the latent profile structure of schizotypy in a non-clinical sample and compared subjective and psychological well-being across schizotypy profiles. Latent profile analysis was conducted on participants' responses (N=420) to the Oxford-Liverpool Inventory of Feelings and Experiences. Six latent profiles emerged: Low Schizotypy, Average, High Schizotypy, High Unusual Experiences (UE), High Introvertive Anhedonia, and High Introvertive Anhedonia/Cognitive Disorganization. Individuals in the profile characterized by high UE without negative, disorganized or impulsive features tended to endorse similar levels of well-being as the Average and Low Schizotypy profiles. With some exceptions, all three profiles also demonstrated significantly greater subjective and psychological well-being when compared to negative/disorganized schizotypy profiles. The UE profile most closely aligns with previous conceptualizations of "healthy schizotypy." Future research should investigate how individuals in this profile make sense of unusual or ambiguous experiences that may lead to distress in clinical populations.

Testing measurement invariance of the schizotypal personality questionnaire-brief scores across Spanish and Swiss adolescents

BACKGROUND

Schizotypy is a complex construct intimately related to psychosis. Empirical evidence indicates that participants with high scores on schizotypal self-report are at a heightened risk for the later development of psychotic disorders. Schizotypal experiences represent the behavioural expression of liability for psychotic disorders. Previous factorial studies have shown that schizotypy is a multidimensional construct similar to that found in patients with schizophrenia. Specifically, using the Schizotypal Personality Questionnaire-Brief (SPQ-B), the three-dimensional model has been widely replicated. However, there has been no in-depth investigation of whether the dimensional structure underlying the SPQ-B scores is invariant across countries.

METHODS

The main goal of this study was to examine the measurement invariance of the SPQ-B scores across Spanish and Swiss adolescents. The final sample was made up of 261 Spanish participants (51.7% men; M = 16.04 years) and 241 Swiss participants (52.3% men; M = 15.94 years).

RESULTS

The results indicated that Raine et al.'s three-factor model presented adequate goodness-of-fit indices. Moreover, the results supported the measurement invariance (configural and partial strong invariance) of the SPQ-B scores across the two samples. Spanish participants scored higher on Interpersonal dimension than Swiss when latent means were compared.

DISCUSSION

The study of measurement equivalence across countries provides preliminary evidence for the Raine et al.'s three-factor model and of the cross-cultural validity of the SPQ-B scores in adolescent population. Future studies should continue to examine the measurement invariance of the schizotypy and psychosis-risk syndromes across cultures.

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.

Psychotic-like or unusual subjective experiences? The role of certainty in the appraisal of the subclinical psychotic phenotype

The multi-dimensional features of Unusual Subjective Experiences (USEs) may be more accurate indicators of psychosis-proneness than simple frequency count. We tested whether subjective certainty or uncertainty of the occurrence of USEs can influence perceived wellbeing. Five hundred and four undergraduate students completed measures of delusion- and hallucination-proneness, general health and emotional processing. Participants' responses on the delusion- and hallucination-proneness scales were dichotomized on the basis of their certainty level. Results showed that, USEs rated with certainty were associated with poor self-perceived health and difficult emotional processing, while those rated with uncertainty were not. Certainty of USEs was associated with increased distress and may be important in characterizing psychopathological significance. Specific characteristics associated with USEs may be more important than their frequency in predicting psychosis risk.