Schizotypal Personality Questionnaire (SPQ)
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KeywordsProspective Memory Gray Matter Volume Negative Priming Schizophrenia Spectrum Disorder Paranoid Ideation
The Schizotypal Personality Questionnaire (SPQ) (Raine 1991) is a commonly used self-report measure of schizotypy in healthy community samples. In recent years, the risk for schizophrenia spectrum disorders predisposed by schizotypy has received increasing attention in the literature. What is schizotypy? Is it a continuum or a categorical construct? How is it measured by the SPQ? Why is it important to measure schizotypy? This entry addresses these questions and reviews the major correlates of schizotypy assessed by the SPQ.
The SPQ Three-Factor Structure
The Schizotypal Personality Questionnaire (SPQ) is a 74-item self-report questionnaire originally designed for screening schizotypal personality disorder in the general community and also researching the correlates of schizotypy (Raine 1991). Modeled after DSM-III-R schizotypal personality disorder diagnostic criteria, the SPQ measures three well-replicated factors of schizotypy: cognitive-perceptual deficits, interpersonal deficits, and disorganization (Raine 1991; Venables and Raine 2015). This factor structure of the SPQ parallels that reported in people with schizophrenia. Raine and Benishay (1995) developed a shorter version, the Schizotypal Personality Questionnaire-Brief (SPQ-B), with 22 items tapping the same three-factor schizotypy construct. Given that the SPQ is initially designed for adults, a downward extension, the SPQ-Child (SPQ-C) modeled on the SPQ-B has been developed specifically for children and adolescents (Raine et al. 2011).
Comprised of yes-no statements, the SPQ measures the three-factor schizotypy construct that is based on all nine DSM-IV criteria for schizotypal personality disorder (American Psychiatric Association 1994). According to Raine (1991, 2006), the “cognitive-perceptual” dimension (positive schizotypy) refers to ideas of reference, magical thinking, unusual perceptual experiences, and paranoid ideation; the “interpersonal” dimension (negative schizotypy) describes social anxiety, lack of close friends, blunted affect, and paranoid ideation, while the “disorganized features” dimension is characterized by odd behavior and speech. Fifty-five percent of those scoring in the top 10% on the SPQ have schizotypal personality disorder (Raine 1991). In terms of the psychometric properties, the validity and internal reliability of the three-factor construct has been established (e.g., Raine and Benishay 1995). The SPQ was found to correlate at a relatively high level (r = 0.68) with independent clinical ratings of DSM-III-R schizotypal traits (Raine 1991). While the three-factor model has been widely accepted in the general population, Stefanis et al. (2004) have also provided an alternative four-factor model that includes a paranoid factor.
There are a number of advantages for studying schizotypy in ostensibly healthy samples. Firstly, it is more cost-effective to prevent than to intervene. Secondly, examining schizotypy instead of schizophrenia which is complicated by medications can help us better understand the development and etiology of schizophrenia spectrum disorders. Thirdly, the prevalence of having psychotic experiences is much higher than being diagnosed with non-affective psychotic disorder.
Cross-Cultural Validity of the SPQ
The three-factor SPQ has established construct validity in various samples with a diverse demographic background. For instance, Reynolds et al. (2000) examined Mauritians comprised of Chinese, French, and individuals with Indian decent and African origin. It was found that the SPQ construct is independent of culture, gender, religious affiliation, psychopathology, and family adversity.
Despite the fact that gender differences have been found in terms of the SPQ scores (Raine 1992), the three-factor construct applies to both male and female participants (Raine et al. 2011). Moreover, the SPQ has also been administered to various age groups including children and adolescents (Raine et al. 2011), university students (Lam et al. 2016), and adults (Koychev et al. 2016; Raine 1991). These studies involved individuals from various countries including China (Raine et al. 2011) and the United States (Raine 1991). In sum, the three-factor schizotypy construct is applicable to both adolescent and adult community samples. Among the few studies that administered the SPQ to a clinical sample, Axelrod et al. (2001) examined adolescent psychiatric inpatients with the SPQ-B and documented satisfactory internal consistency, factor structure, and convergent validity.
There is moderate heritability of schizotypy as measured by the SPQ in adolescents (Ericson et al. 2011). Specifically, as measured by the SPQ-C, Ericson et al. (2011) showed the heritabilities of 42–53% at age 11–13 years and 38–57% at age 14–16 years for all three SPQ factors. Moreover, the developmental stability across these two age groups was 0.56, and 70.5% of this stability could be explained genetically. Along the same line, the relatives of schizophrenics were shown to have elevated ratings on the cognitive-perceptual factor of the SPQ (Yaralian et al. 2000). Taken altogether, schizotypy as assessed by the SPQ is moderately heritable.
Regarding the genetic basis of schizotypy, it has been suggested to be an endophenotype for schizophrenia which has a high heritability (66–83%) (Cardno et al. 1999) and a prevalence rate of 2% (Raine 2006). According to Barrantes-Vidal et al. (2013), positive schizotypy is associated with psychotic-like, paranoid, schizotypal, and mood symptoms, while negative schizotypy, on the other hand, is associated with negative and schizoid symptoms. Moreover, various studies found that schizotypy and schizophrenia spectrum disorders share multiple genetic, behavioral, and neurobiological correlates which give rise to the development of these disorders. For instance, Fanous et al. (2007) found that at least a subset of schizophrenia susceptibility genes overlap those of schizotypy in nonpsychotic relatives.
As measured specifically by the SPQ, schizotypy is associated with cognitive deficits including impaired verbal fluency and negative priming (Cochrane et al. 2012), impairments in working memory (Schmechtig et al. 2013), poor recognition and naming of facial emotion expressions (Germine and Hooker 2011), deficits in attention (Chen et al. 1997), and impaired theory of mind (Deptula and Bedwell 2015). On contrast, it was suggested that general intelligence is not impaired in schizotypy (Raine 2006).
Recent research has shed more light on both the structural and functional neuroimaging domains of schizotypy. As measured by the SPQ, schizotypy is positively related to cortical thickness in the frontal lobe and negatively related to the volume of frontal and temporal lobes as well as the thalamus (DeRosse et al. 2015; Kühn et al. 2012). Gray matter volume (GMV) of the right dorsolateral prefrontal cortex (Kühn et al. 2012) is related to positive schizotypy, while right temporal-parietal junction (Kühn et al. 2012) and right precuneus GMV (Nenadic et al. 2015) are related to negative schizotypy. These findings suggest that schizotypy is associated with volumetric changes in the brain. However, numerous neuroimaging studies have been conducted in schizophrenia and schizotypal personality disorder, while those pertaining to individual differences in schizotypal personality are more limited.
As to functional neuroimaging studies, neural processing patterns have been found to underlie a number of cognitive-related paradigms in schizotypy as assessed by the SPQ. For example, a high level of schizotypy was associated with reduced activation in the prefrontal cortex while performing a task regarding prospective memory which refers to the ability to remember to perform actions (Wang et al. 2014). Besides these activation paradigms, some recent studies have also examined the schizotypal brain at rest. For instance, one resting-state functional MRI study in young people aged 12–20 years reported positive correlations between SPQ scores and a visual network (involving the occipital and bilateral temporal regions) in the low-frequency range and negative correlations between the SPQ scores and an auditory network (the superior temporal and inferior frontal gyrus) (Lagioia et al. 2010).
Besides MRI studies, the relationship between schizotypy (measured by the SPQ) and brain function has also been examined by different methods including electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) (e.g., Kim et al. 2015). For instance, an event-related potentials (ERPs) study found that the high schizotypy group related to reduced error-related negativity amplitudes performed worse than the low schizotypy group in error-monitoring (the ability to monitor one’s own behavior, such as detecting errors and correcting or adjusting one’s behavior to achieve the intended purposes) (Kim et al. 2015). Taken together, schizotypy is associated with various neurocognitive impairments as well as structural and functional brain abnormalities.
Regarding the psychopharmacology of schizotypy, studies have gone beyond behavioral changes to neural changes resulting from medication. For instance, as measured by the SPQ, dopamine transmission in both striatal and extra-striatal brain regions has been associated with schizotypy (Woodward et al. 2011). Similar to medicated schizophrenics, the D2/D3 receptor antagonist amisulpride (Koychev et al. 2012) and antipsychotic compounds (Schmechtig et al. 2013) have been found to be effective in improving neurocognitive functions in schizotypy. These findings suggest that the psychopharmacology reducing schizotypy is similar to that used in treating schizophrenia.
Early Environmental Enrichment and Skills Training
Besides medications, there are various types of interventions targeting schizotypy. For example, an early nutritional, education, and physical exercise enrichment program for children at ages 3–5 years was effective in reducing their schizotypy level and antisocial behavior at age 17 years (Raine et al. 2003). Furthermore, a psychosocial skill training intervention developed by Liberman and Robertson (2005) was also effective in reducing schizotypal traits and enhancing social competence in high school students at 12-month follow-up.
The SPQ is a well-validated assessment tool for measuring a three-factor schizotypy construct in healthy individuals across various demographic backgrounds. Nevertheless, a four-factor model (cognitive/perceptual, paranoid, negative, and disorganization schizotypal dimensions) is worthy of future consideration (Stefanis et al. 2004). Venables and Raine (2015) found a modest stability of the three-factor schizotypy construct (r = 0.58) by following up individuals from adolescence into adulthood.
Prior findings have illustrated the importance of identifying those with raised levels of schizotypy as the risk of the development of schizophrenia spectrum disorders is posed, especially during childhood and adolescence. Not only will such identification benefit the community financially, but it also helps prevent abnormal behavior and related social dysfunction including schizotypal symptomatology and aggression which might potentially lead to future crime in society. Moreover, since schizotypy is moderately heritable and is associated with various clinical disorders (e.g., schizophrenia), neurocognitive deficits (e.g., working memory and theory of mind), as well as structural and functional brain abnormalities, future brain imaging studies could be conducted utilizing various methodologies ranging from EEG to MRI to delineate and confirm the neuropsychological and genetic underpinnings of schizotypy. More importantly, the development and evaluation of interventions targeting schizotypy is warranted in future studies.
- American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.Google Scholar
- Cardno, A. G., Marshall, E. J., Coid, B., Macdonald, A. M., Ribchester, T. R., Davies, N. J., …, & Gottesman, I. I. (1999). Heritability estimates for psychotic disorders: The Maudsley twin psychosis series. Archives of General Psychiatry, 56(2), 162–168.Google Scholar
- Fanous, A. H., Neale, M. C., Gardner, C. O., Webb, B. T., Straub, R. E., O’Neill, F. A., …, & Kendler, K. S. (2007). Significant correlation in linkage signals from genome-wide scans of schizophrenia and schizotypy. Molecular Psychiatry, 12(10), 958–965.Google Scholar
- Koychev, I., Joyce, D., Barkus, E., Ettinger, U., Schmechtig, A., Dourish, C. T., …, & Deakin, J. F. W. (2016). Cognitive and oculomotor performance in subjects with low and high schizotypy: Implications for translational drug development studies. Translational Psychiatry, 6(5), e811.Google Scholar
- Koychev, I., McMullen, K., Lees, J., Dadhiwala, R., Grayson, L., Perry, C., …, & Dourish, C. T. (2012). A validation of cognitive biomarkers for the early identification of cognitive enhancing agents in schizotypy: A three-center double-blind placebo-controlled study. European Neuropsychopharmacology, 22(7), 469–481.Google Scholar
- Lagioia, A., Van De Ville, D., Debbané, M., Lazeyras, F., & Eliez, S. (2010). Adolescent resting state networks and their associations with schizotypal trait expression. Frontiers of Systems Neuroscience, 4(35), 66–77.Google Scholar
- Nenadic, I., Lorenz, C., Langbein, K., Dietzek, M., Smesny, S., Schönfeld, N., …, & Gaser, C. (2015). Brain structural correlates of schizotypy and psychosis proneness in a non-clinical healthy volunteer sample. Schizophrenia Research, 168(1–2), 37–43.Google Scholar
- Schmechtig, A., Lees, J., Grayson, L., Craig, K. J., Dadhiwala, R., Dawson, G. R., …, & Migo, E. M. (2013). Effects of risperidone, amisulpride and nicotine on eye movement control and their modulation by schizotypy. Psychopharmacology, 227(2), 331–345.Google Scholar
- Wang, Y., Yang, T., Su, L., Yan, C., Wang, Y., Huang, J., …, & Chan, R. C. K. (2014). Neural correlates of prospective memory in individuals with schizotypal personality features. Neuropsychology, 28(3), 373–381.Google Scholar
- Woodward, N. D., Cowan, R. L., Park, S., Ansari, M. S., Baldwin, R. M., Li, R., …, & Zald, D. H. (2011). Correlation of individual differences in schizotypal personality traits with amphetamine-induced dopamine release in striatal and extrastriatal brain regions. American Journal of Psychiatry, 168, 418–426.Google Scholar