Towards a Schizotypy Core: Convergence and Divergence of Two Empirically-Derived Self-Report Measures from a Nonclinical Sample

Abstract

Schizotypal personality traits are important for understanding the various manifestations of schizophrenia-spectrum liability. Data from a recent study suggests that the Wisconsin Schizotypy Scales and the Schizotypal Personality Questionnaire converge into positive and negative factors, though it is unclear whether these measures are redundant or whether they tap distinct facets of these latent constructs. The present study used item-level Exploratory Structural Equation Modeling (ESEM) of two empirically derived revisions of these scales, the WSS – Short Form (WSS-SF) and the SPQ – Brief Revised (SPQ-BR). ESEM analysis of the SPQ-BR supported a seven-factor subordinate and three-factor superordinate solution, whereas that of the WSS-SF revealed a three factor solution. Concurrent item-level ESEM of the SPQ-BR and WSS-SF revealed a four factor solution: positive, negative, disorganized and physical anhedonia. Nearly all of the factors identified from these ESEMs explained unique variance in clinical symptoms and, in the case of the negative factors, treatment history. These data provide further evidence that schizotypy is heterogeneous with a similar structure as seen in schizophrenia and that it may not be adequately captured by an individual measure.