Validation of a Spanish version of the Schizotypal Personality Questionnaire (SPQ): Psychometric characteristics and underlying factor structure derived from a healthy university student sample

Abstract

Objective. The need for early detection, prevention and intervention in psychosis has prompted the study of prodromal and threshold syndromes. One strategy involves the assessment of schizotypy, a personality construct involving unusual perceptual experiences, magical thinking or bizarre behavior. Sensitive measurement instruments could potentially allow detection of signs heralding transition to psychosis in high-risk individuals, or risk of relapse in patients after a first psychotic episode. The Schizotypal Personality Questionnaire (SPQ) is a self-report scale, originally developed for English speakers, that covers the nine DSM-IV criteria for schizotypal personality disorder (SPD). Our aim was to validate a Spanish version of the SPQ and assess its psychometric properties.

Methods. The original SPQ was back-translated and administered to university students (n=250). We assessed the internal consistency, the convergent, discriminant and criterion validity of the instrument, and analyzed its factor structure.

Results. Our version of the SPQ showed good internal consistency, and convergent (O-LIFE), discriminant (P-scale of EPQ) and criterion validity (SCID-II). Factor analyses supported a four-factor structure in fitting SPQ data.

Conclusions. Our Spanish version of the SPQ questionnaire preserved the psychometric properties of the original questionnaire. This adaptation will provide a useful tool for the early detection of prodromal schizophrenia symptoms and clinical relapse in Spanish-speaking populations.