EXECUTIVE-FRONTAL LOBE COGNITIVE DYSFUNCTION IN SCHIZOPHRENIA - A SYMPTOM SUBTYPE ANALYSIS

Impairment of executive-frontal lobe functioning, affecting the planni ng, initiation and regulation of goal-directed behavior, is a common c ognitive deficit in schizophrenia. However, it is unclear if deficits in these frontal-lobe-mediated abilities are differentially expressed across clinical subgroups. We analyzed executive-frontal abilities in relation to symptom expression in 53 hospitalized schizophrenic patien ts. Patients were assigned to one of three subgroups based on rank ord er analysis of Brief Psychiatric Rating Scale factors: Withdrawal-Reta rdation, Reality Distortion and Conceptual Disorganization. Executive- frontal tests included Visual Search, Verbal Fluency, Verbal Series At tention, Trail Making - Part B, Symbol Digit, Hopkins Verbal Learning, Digit Span, Wisconsin Card Sorting, Stroop Color-Word and Attentional Capacity. The schizophrenia group showed significant deficits relativ e to healthy control subjects (n = 20) on all tests. Exploratory facto r analysis of test scores revealed three factors: (i) Verbal Processin g/Memory; (ii) Cognitive Flexibility/Attention; and (iii) Psychomotor Speed/Visual Scanning. The three symptom subgroups were differentially impaired on executive-frontal abilities: Withdrawal-Retardation on ps ychomotor speed, verbal fluency, working memory, visual search and cog nitive flexibility; Conceptual Disorganization on attention; Reality D istortion on verbal memory. The results have implications for syndrome definition, pharmacological intervention and prediction of outcome in schizophrenia. (C) 1998 Elsevier Science Ireland Ltd. All rights rese rved.