Toward a more psychometrically sound brief measure of schizotypal traits: introducing the SPQ-Brief Revised.

Psychometric case identification of individuals at risk for developing schizophrenia-spectrum disorders is an important enterprise. Unfortunately, current instruments for this purpose are limited. The present studies sought to improve the Schizotypal Personality Questionnaire-Brief (SPQ-Brief), a measure of schizotypal traits that has come under recent criticism. In the first study, we conducted exploratory factor analysis on the SPQ-Brief using a Likert-style scoring format in a large sample of nonclinical adults. Although acceptable internal consistency was found, the original factor structure was not supported. In the second study, we administered the full version of the SPQ to a separate large nonclinical adult sample and employed exploratory and confirmatory factor analysis to identify critical items that could be used to revise the SPQ-Brief. The end product of these studies is the SPQ-Brief Revised, which offers a subordinate seven-factor and super-ordinate three or four factor solution, employs a Likert-scale format to improve sensitivity, and is brief (34 items).