Assessing disturbed thinking and cognition using the Ego Impairment Index in older schizophrenia patients: paranoid vs. nonparanoid distinction

Abstract

Objective: We compared thought-disturbance via the Rorschach-derived Ego Impairment Index (EII) between DSM-IV paranoid vs. nonparanoid (undifferentiated and disorganized) subtypes of older schizophrenia patients. Methods: 44 DSM-IV medically stable outpatients with schizophrenia (27 paranoid, 17 nonparanoid) and 45 normal comparison participants aged 45–100 years were assessed using the EII, a Rorschach-derived cognitive-based measure of disturbed thinking. Group differences on the EII and the relation of this measure to key demographic and clinical variables were examined. Results: Nonparanoid schizophrenia patients demonstrated significantly greater impairment on the EII than their paranoid counterparts. The EII performance of paranoid patients was similar to normal comparison participants. Furthermore, the paranoid patients displayed better premorbid intellectual functioning, less negative symptoms, and better global cognitive performance than nonparanoid patients. Finally, greater impairment on the EII was correlated with poor performance on a global measure of cognitive ability. Conclusions: The present findings substantiate previous work suggesting that nonparanoid patients have a form of the illness characterized by worse premorbid functioning and greater disturbed thinking and cognition than their paranoid counterparts.