DIMENSIONS OF SCHIZOPHRENIC POSITIVE SYMPTOMS - AN EXPLORATORY FACTOR-ANALYSIS INVESTIGATION

Current psychopathology classifies schizophrenic positive symptoms int o four groups: delusions, hallucinations, formal thought disorder, and catatonic symptoms. The present study explores the factor structure o f different positive symptoms to refine this classification. The 35 po sitive symptoms of 429 psychiatric patients, consecutively admitted to any of 95 mental hospitals, with diagnosis of the ICD-10 F20 schizoph renia, were studied. After excluding those items with a base rate of 1 0% or less, factor analysis yielded six factors. The first factor was loaded by most of Schneider's first-rank symptoms and two specific aud itory hallucinations; the second by all the catatonic symptoms and inc oherence; the third by bodily delusions/hallucinations; the fourth by delusions of persecution and reference; the fifth by grandiose and rel igious delusions; and the sixth by visual and miscellaneous hallucinat ions. The finding that schizophrenic positive symptoms may have more t han four dimensions suggests the need for reclassification of schizoph renic symptoms and for reconsideration of evidence-based diagnostic cr iteria for the disorder.