Determinants of neurological dysfunction in first episode schizophrenia

Abstract

Background. Although it is well recognized that individuals with schizophrenia display evidence of subtle neurological impairment, its aetiopathological and clinical significance continues to be unclear.Methods. Patients presenting with a first episode of schizophrenia or schizophreniform psychosis (DSM-IV criteria) were examined using two previously validated neurological examinations. The majority (N = 35) were examined prior to their ‘first ever’ dose of neuroleptic while the remaining patients (N = 21) had been medicated for less than one month. The manner in which neurological functioning is influenced by symptomatology and handedness was ascertained.Results. The majority of patients who were examined neuroleptic-naive displayed evidence of neurodysfunction. A combination of relative hand preference and symptomatology explained a significant proportion of the variance in neurological functioning. Mixed handedness among adults at the time of first presentation with schizophrenia was associated with more severe neurological impairment and a history of poorer scholastic attainment and pre-morbid social adjustment.Conclusions. Neurological soft signs are an intrinsic part of schizophrenia rather than a direct consequence of treatment. Early developmental processes are associated with the level of subsequent neurological impairment in first episode schizophrenia. However, symptomatology appears to have an influence on the apparent severity of neurological impairment.