Objective and subjective extrapyramidal side effects in schizophrenia: their relationships with negative and...

The aim of this study was to show that objective extrapyramidal symptoms (O-EPS) were strongly correlated to negative and depressive symptoms while subjective extrapyramidal symptoms (S-EPS) were not. Ninety-one schizophrenic patients were evaluated by the Extrapyramidal Symptoms Rating Scale (ESRS), Montgomery and Asberg Depression Rating Scale (MADRS) and Scale for the Assessment of Negative Symptoms (SANS). While significant correlations were found between O-EPS and SANS (r = 0.51; p < 0.001) and between O-EPS and MADRS (r = 0.26; p < 0.01), no significant relationship existed between S-EPS and SANS (r = 0.19) or MADRS (r = 0.19). Similar results regarding the relationships between EPS and SANS were found in stabilized and acute subgroups and in deficit and nondeficit subgroups. A stepwise multiple regression showed that 41% of the variance of the SANS scores was due to facial mask and bradykinesia, and that 17% of the variance of the MADRS scores was due to facial mask and akathisia. This study shows the interest of evaluating subjective parkinsonism symptoms over objective ones since they are less interrelated to other symptoms, in particular to negatives ones.