Extrapyramidal symptoms and neuropsychological deficits in schizophrenia

Background: Extrapyramidal (EP) symptoms and neuropsychological (NP) deficits are both frequently present among schizophrenia patients. EP symptoms, such as motor slowing, could hinder performance on NP tests, yet little is known about the relationship between EP symptoms and NP functioning among schizophrenia patients. Methods: Using a comprehensive NP test battery and standard ratings of EP symptoms and other psychiatric characteristics, we conducted a cross-sectional exploration of the association between EP symptoms and NP functioning among 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 indicated that the relationship between EP symptoms and NP deficits was not accounted for by slowed motor or mental processing, demographic characteristics, severity of psychopathology, dyskinesia, or medication status. Conclusions: The pathophysiological mechanisms underlying EP symptoms and some NP deficits in schizophrenia may overlap.