Schizotypal Personality Questionnaire (SPQ)
Also known as: SPQ, Raine Schizotypal Scale
The SPQ is a 74-item self-report measure of schizotypal personality traits across cognitive-perceptual, interpersonal, and disorganized domains. Developed by Adrian Raine in 1991 based on DSM-III-R schizotypal personality disorder criteria, it is the most widely used dimensional measure of schizotypy on the psychosis spectrum. The SPQ is valuable for identifying psychotic-like experiences and personality features that may increase psychosis vulnerability.
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When to use it
Primary use: dimensional assessment of schizotypal personality traits and psychosis vulnerability across general population and clinical samples. Screening for psychotic-like experiences and personality features in individuals presenting with social anxiety, odd thinking, or relationship difficulties. Longitudinal research examining schizotypy as risk factor for psychosis onset and associations with genetic vulnerability. Measurement in family studies where relatives of psychotic patients may show elevated schizotypy despite no psychotic episodes. Not diagnostic; elevated SPQ indicates schizotypal traits and warrant comprehensive psychotic risk assessment but do not constitute diagnosis.
Strengths & limitations
- Comprehensive schizotypy measurement: 74-item SPQ thoroughly samples cognitive-perceptual, interpersonal, and disorganized domains of schizotypy
- Psychosis spectrum framework: captures intermediate phenotype between normal personality and psychotic disorder; important for understanding psychosis vulnerability
- Three-factor structure provides detail: subscales distinguish magical thinking (cognitive-perceptual) from social dysfunction (interpersonal) from odd behavior (disorganized); enables profile interpretation
- Sensitive to psychosis risk: elevated Cognitive-Perceptual subscale particularly predictive of conversion to psychosis in at-risk samples
- Brief alternative available: SPQ-B (22 items) provides rapid screening while retaining factor structure; efficient for epidemiological studies
- Scale length and complexity: 74-item SPQ requires 15–20 minutes; dichotomous yes/no scoring less granular than Likert-scale alternatives
- Binary response format: yes/no responses lose information about frequency or intensity of symptoms; some items may not capture nuance of experience
- Overlap with other constructs: schizotypy overlaps with obsessive-compulsive traits, social anxiety, neuroticism; discriminant validity with these constructs incomplete
- Limited predictive specificity: elevated schizotypy increases psychosis risk but vast majority with elevated SPQ never develop psychosis; positive predictive value modest
- Cultural variation: schizotypal symptoms and social acceptability vary across cultures; cutoff scores derived from Western samples may not generalize
Frequently asked
Does a high SPQ score mean someone will develop psychosis?
No. Elevated SPQ increases psychosis risk but vast majority with high schizotypy never develop psychotic disorder. Psychosis risk involves multiple factors: elevated schizotypy, functional decline, family history, cannabis use, early stressors. SPQ identifies vulnerability; comprehensive psychotic risk assessment examining these other factors determines actual risk.
What is the difference between schizotypal personality disorder and elevated schizotypy on the SPQ?
Schizotypal personality disorder is a clinical diagnosis requiring schizotypal traits, significant functional impairment, pervasive pattern across contexts, and onset in adolescence/early adulthood. Elevated SPQ indicates presence of schizotypal traits but does not constitute diagnosis. Some individuals have high schizotypy but good functioning and no disorder diagnosis.
What is a typical SPQ score?
Community samples average M≈16–18 SD≈11. Schizotypal personality disorder patients average M≈35–42 SD≈15. First-episode psychosis patients average M≈28–32 SD≈12. Scores ≥31–35 indicate clinically elevated schizotypy; scores <10 indicate minimal schizotypal traits. However, no absolute cutoff for diagnosis; clinical judgment required.
Is the SPQ affected by current psychotic symptoms?
Yes. SPQ may be elevated during acute psychotic episodes due to current perceptual distortions and paranoia. For personality assessment, SPQ ideally administered after psychotic symptoms remit (when assessing stable traits rather than state-dependent acute symptoms). Trait schizotypy often persists even after psychotic symptoms improve.
Is the SPQ available free for research and clinical use?
Yes. The SPQ is in the public domain and freely available for research and clinical use without licensing fees. Reproducible for non-commercial purposes. Cite Raine (1991) original publication.
Sources
- Raine, A. (1991). The SPQ: A scale for the assessment of schizotypal personality based on DSM-III-R criteria. Schizophrenia Bulletin, 17(4), 555–564. DOI: 10.1093/schbul/17.4.555 ↗
How to cite this page
ScholarGate. (2026, June 3). Schizotypal Personality Questionnaire (SPQ). ScholarGate. https://scholargate.app/en/clinical-psychology/schizotypal-personality-scale
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