Introducing the Eppendorf Schizophrenia Inventory (ESI) as a psychometric method for schizotypy research

The Eppendorf Schizophrenia Inventory (ESI) is a new clinical questionnaire designed to measure schizophrenia-specific subjective experiences. Our study evaluated the suitability of the ESI for schizotypy research by comparison with several well-established schizotypy scales. A factor analysis with the data of N = 159 healthy adults including ESI, Schizotypal Personality Scale (STA), Perceptual Aberration Scale (PAS), Schizotypal Personality Questionnaire (SPQ), and Schizotypal Personality Inventory yielded six factors which could be interpreted as positve, negative, and disorganized schizotypy, magical thinking, social anxiety, and psychotic experiences (PSY). PSY consisted of ESI, PAS, STA, and the SPQ subscale of Unusual Perceptual Experiences. Only PSY correlated with cognitive inhibition; only PSY and disorganized schizotypy correlated with mixed-handedness. The results suggest the ESI to be a promising additional method for schizotypy studies.