Sinistrality in subtypes of schizophrenia

Abstract Sinistrality, characterized by an excess of non-right-handedness, has been reported in schizophrenic patients, but the findings are controversial. Aim. As sinistrality could be linked to a failure of hemisphere specialization in schizophrenia that would translate into language disorders, sinistrality was found out in disorganized and positive schizophrenic patients characterized by language disorders. Methods. Seventy-three schizophrenic patients (DSM IV) and 81 controls were evaluated with the Edinburgh Handedness Inventory (EHI). Patients were evaluated and classified into five subtypes (deficit, positive, disorganized, mixed and residual) with the Positive and Negative Syndrome Scale and the Schedule for the Deficit Syndrome. Results. Disorganized patients had a significantly more severe sinistrality in comparison to the deficit, residual and mixed subtypes and controls. A negative correlation was found between the disorganization and the EHI scores ( r  = – 0.34; P r  = 0.06). Conclusion. The findings provided further evidence that the defects in the normal process of lateralization observed in schizophrenia affects primarily disorganized patients.