Characteristic subjective experiences of schizophrenia.

The purpose of the study was to identify subjective experiences that are characteristic of schizophrenia. A questionnaire for self-assessment of disturbances in several cognitive-perceptual areas (the Eppendorf Schizophrenia Inventory) was constructed and administered to first episode schizophrenia patients (SCHf; n = 45), negative-syndrome schizophrenia patients (SCHn; n = 45), remitted schizophrenia subjects (SCHr; n = 24), depressive patients (DEP; n = 43), alcoholic patients (ALC; n = 48), obsessive-compulsive patients (OCD; n = 46), and healthy controls (CON; n = 57). Comparisons between the SCHf, SCHn, DEP, ALC, and OCD groups and a subsequent factor analysis revealed four schizophrenia-specific dimensions: Attention and Speech Impairment (AS), Ideas of Reference (IR), Auditory Uncertainty (AU), and Deviant Perception (DP). Further analyses suggested that the AS syndrome represents a mediating vulnerability factor, while IR, AU, and DP probably are reversible episode indicators. The results may contribute to the refinement of the measurement of specific prepsychotic signs, thus facilitating the development of early intervention approaches.