The Schizotypal Personality Questionnaire – Child (SPQ-C): Psychometric properties and relations to behavioral problems with multi-informant ratings

Highlights

• Schizotypal personality disorder is a mental health disorder which has increasingly gained attention, particularly in children and adolescents, yet the screening tool is limited.

• Schizotypal Personality Questionnaire – Child (SPQ-C) was developed to screen for schizotypy in young children and adolescents.

• The Chinese version of the SPQ-C replicated a three factor structure with adequate psychometric properties.

• Partial measurement invariance was achieved across gender and residence.

• Good convergent validity was established between the SPQ-C and other standardized parent- and teacher-rated measures of children's behavioral problems.

Abstract

The Schizotypal Personality Questionnaire (SPQ) is one of the most widely used screening tools for schizotypy in adults. The Schizotypal Personality Questionnaire-Child version (SPQ-C) was recently developed to assess schizotypy in children and has a similar three-factor structure to the adult SPQ (i.e., Cognitive-Perceptual, Interpersonal-Affective, and Disorganization). However, few studies to date have reported on the psychometric properties and the usefulness of the SPQ-C in Eastern populations, including Mainland China. This study presents the first psychometric assessment of the Chinese SPQ-C in Mainland China. Exploratory factor analysis and confirmatory factor analysis were used to assess the factor structure of the SPQ-C in 1668 children (M = 12.10, SD = 0.60 years) from the China Jintan Child Cohort Study. Our findings document a three-factor structure and partial measurement invariance across residential location and gender, replicating the psychometric properties of the SPQ-C in English. The Chinese SPQ-C further correlates with standard behavioral problems (i.e., Child Behavior Checklist, Youth Self-Report and Teacher Report Form), demonstrating construct validity and utility as a child psychopathology assessment tool. Our findings provide the first robust psychometric evidence for a three-factor structure of the Chinese SPQ-C in a large Mainland Chinese sample, and suggest that the SPQ-C is suitable as a screening tool for schizotypy in community children who may be at risk for behavioral problems and later psychosis.

Introduction

Schizotypal personality disorder (SPD) or schizotypy is thought to be a premorbid condition for psychosis (Lenzenweger, 2018, Meehl, 1962, Meehl, 1990) that exists on a continuum between schizotypal traits (phenotypic expression) and schizophrenia-spectrum disorder (latent liability) (Debbané and Barrantes-Vidal, 2014, Fonseca Pedrero and Debbané, 2017, Raine, 2006). For these reasons, research interest in schizotypy has grown over the years in the hope of better understanding the etiology of schizophrenia (Bedwell and Donnelly, 2005, Kline and Schiffman, 2014, Mason, 2015, Raine, 2006).

Schizotypy is characterized by three-factors and nine underlying symptoms: Cognitive-Perceptual (Factor 1: magical thinking or odd beliefs, unusual perceptual experiences, ideas of reference, paranoid ideation or suspiciousness); Interpersonal (Factor 2: lack of close friends or confidants, detached or flattened affect, undue social paranoid ideation); and Disorganized features (Factor 3: odd or eccentric behavior, and odd speech) (Association, 2013, Ettinger et al., 2014). All three inter-correlate but distinct factors have utility in identifying unique neurocognitive and behavioral profiles that may inform the etiology of schizophrenia (Barrantes-Vidal et al., 2015, Chen et al., 1997, Cohen et al., 2015, Fonseca-Pedrero et al., 2018, Kline and Schiffman, 2014, Raine, 2006, Stotesbury et al., 2018). Thus, it is important to develop an assessment tool in the general community population to identify early signs of schizotypal personality disorder.

To date, for adults the 74-item self-report Schizotypal Personality Questionnaire (SPQ) (Raine, 1991) and its subsequent 22-item brief version (Schizotypal Personality Questionnaire-Brief: SPQ-B) (Raine and Benishay, 1995) have been the most widely used screening tools for schizotypy and its three-factor structure (Fonseca-Pedrero et al., 2017b, Mason, 2015). Numerous studies have repeatedly demonstrated excellent psychometric properties for the three-factor structure of the SPQ across cultures (Compton et al., 2007, Ma et al., 2015, Moreno-Izco et al., 2015, Ortuño-Sierra et al., 2013, Reynolds et al., 2000, Venables and Raine, 2015) and more recently, the three factor structure of the SPQ-B across 14 countries, omega coefficient = 0.86–0.92 (Fonseca-Pedrero et al., 2017a). The full-length adult version has also been administered to Dutch children (van Rijn and Swaab, 2011). An important advantage of the SPQ over other scales which led to its selection in this study is that it represents all nine DSM features of schizotypal personality, and as such has higher content validity than other scales. The SPQ and SPQ-B have high internal consistency (SPQ_alpha = 0.91; SPQ-B_alpha = 0.72–0.80), test-retest reliability (SPQ_r = 0.82; SPQ-B_r = 0.86–0.095), convergent validity (SPQ_r = 0.59–0.81), discriminant validity and criterion validity with the SCID-II (SPQ_r = 0.63 and 0.68) (Bedwell et al., 2006, Compton et al., 2007, Fonseca-Pedrero et al., 2009, Mason, 2015, Mata et al., 2005). Although the adult 74-item SPQ has already been demonstrated to be reliable in Chinese populations (N = 538) (Guo et al., 2011), the availability of a reliable and easily-administered screening instrument for children is lacking. While there are issues regarding early detection and prevention of mental health in the general population (Costello, 2016), a schizotypy measure for children may still be of interest to clinicians monitoring symptom conversion to psychosis and researchers working with younger samples.

Though less well-researched, the equivalent modified child version consists of the Schizotypal Personality Questionnaire-Child (SPQ-C) (Raine and Baker, 2003). It has minor wording adjustments and has also been found to be reliable (alpha = 0.80–0.92) and suitable for use in young children and adolescents. To date, only three published studies have investigating the SPQ-C. Ericson et al. (2011) showed in a longitudinal twin study (n = 1457) in the US that each of the three factors was moderately heritable (h² = 42–53%, age 11–13 years; h² = 38–57%, age 14–16 years) and stable across a 3-year period (r = 0.26–0.48). In Hong Kong, Raine et al. (2011) administered a Chinese translated version of the SPQ-C to a large sample of 8–16 year olds (n = 3804) and found a three factor structure of schizotypy. In another study of Singaporean adolescents (mean age = 13.99 years), self-reported SPQ-C total scores were positively associated with both self-reported aggression (more strongly for reactive than proactive) and anxiety (Seah and Ang, 2008). However, all three of these studies relied on child self-report; thus, observed relationships with other child report scales may be inflated. Few studies to date have examined the SPQ's convergent validity with other behavioral assessments completed by different informants. This remains to be investigated and has important implications for clinician's decisions on informant selection to confirm the child assessment of schizotypy and the structure of the SPQ-C in a Mainland Chinese sample. Although the SPQ-C has already been applied to a Chinese youth population in Hong Kong, it is of interest to examine it within a Mainland Chinese sample because personality disorders may vary widely within the context of culture (Ronningstam et al., 2018). Furthermore, the predominant language in Hong Kong is not Mandarin Chinese but Cantonese. Other differences between mainland China and Hong Kong include individuals’ perceptions of personalities and psychopathologies, social norms, political structure, economic development and level of modernization (Lin, 1997). As such, the two regions could be expected to have varying levels of psychopathology. Developing culturally-appropriate assessment tools could help test for true differences in the presence of schizotypal traits in these regions and test for generalizability of findings to, in this case, mainland Chinese children in the community.

As evidenced by the growing benefits of early intervention and the increasing feasibility of detecting mental deterioration 5 years prior to a clinical diagnosis (Gafoor et al., 2010, McGorry et al., 2002, van der Gaag et al., 2013), both of which can improve clinical outcomes for psychosis (Singh, 2010), there is a clear advantage in developing culturally-appropriate screening tools such as the SPQ-C to assess large community samples of children at a relatively early stage of development (Barrantes-Vidal et al., 2015). Currently, higher scores on the adult SPQ have been found to reflect greater neurobiological and genetic vulnerabilities (Avramopoulos et al., 2002, Barrantes-Vidal et al., 2015, Ettinger et al., 2014, Ettinger et al., 2015, Fonseca-Pedrero et al., 2018, Vollema et al., 2002). High incidence rates have also been associated with a number of neuropsychiatric syndromes such as obsessive-compulsive disorder (Aycicegi et al., 2005, Barrantes-Vidal et al., 2015, Cohen et al., 2015, Ettinger et al., 2015, Fonseca-Pedrero et al., 2018). In children, there is initial evidence to suggest that higher scores on the SPQ-C have been related to higher levels of childhood aggressive behaviors, specifically reactive aggression, and that peer victimization mediates 56% of this relationship (Raine et al., 2011). Clearly, early detection of schizotypal traits holds important implications for our understanding of the correlates and etiology of schizophrenia and has the potential to identify children at risk for high levels of schizotypal traits as well as other behavioral problems early in development.

To our knowledge, only three studies to date have used the SPQ-C (Ericson et al., 2011, Raine et al., 2011, Seah and Ang, 2008), with none utilizing a mainland Chinese sample. The current study addresses this gap by providing the first assessment of the psychometric properties of the Chinese SPQ-C in a large community sample of 1668 children (aged 12 years). The aims of this study were three-fold: first, exploratory and confirmatory factor analyses were conducted to examine the structure of the Chinese SPQ-C; second, we tested the measurement invariance of the SPQ-C across gender and residential location in order to ensure that the construct is stable across groups; and third and finally, we tested the convergent validity of the SPQ-C with standardized measures of child behavioral problems (social, thought, attention, internalizing, and externalizing) reported by the child's parents and teachers.