Extrapyramidal symptoms and neuropsychological deficits in schizophrenia

Background: Extrapyramidal (EP) symptoms and neuropsychological (NP) defici ts are both frequently present among schizophrenia patients. EP symptoms, s uch as motor slowing, could hinder performance on NP tests, yet little is k nown about the relationship between EP symptoms and NP functioning among sc hizophrenia patients. Methods: Using a comprehensive NP test battery and standard ratings of EP s ymptoms and other psychiatric characteristics, we conducted a cross-section al exploration of the association between EP symptoms and NP functioning am ong 96 middle-aged and elderly outpatients with schizophrenia. Results: Severity of EP symptoms was associated with worse NP performance, particularly the areas of learning and motor skills. Regression analyses in dicated that the relationship between EP symptoms and NP deficits was nor a ccounted for by slowed motor or mental processing, demographic characterist ics, severity of psychopathology, dyskinesia, or medication status, Conclusions: The pathophysiological mechanisms under-lying EP symptoms and some NP deficits in schizophrenia may overlap. (C) 1999 Society of Biologic al Psychiatry.