Risperidone, 2 mg/day vs. 4 mg/day, in First-Episode, Acutely Psychotic Patients: Treatment Efficacy and Effects on Fine Motor Functioning

Background: The aim of this study was to examine differences in the improvement of clinical psychopathology and in fine motor functions at 2 doses of risperidone in first-episode, acutely psychotic patients.

Method: In a double-blind, fixed-dose study, 49 acutely psychotic, neuroleptic-naive patients who were admitted for the first time and who met DSM-IV criteria for schizophrenia, schizophreniform disorder, or schizoaffective disorder were randomly assigned to 2 or 4 mg/day of risperidone. Treatment efficacy was measured using the Brief Psychiatric Rating Scale, the Scale for the Assessment of Negative Symptoms, The Clinical Global Impressions scale, and the Social and Occupational Functioning Assessment Scale. Fine motor functions were assessed using a computerized device (the Vienna Test System) and were compared with those of a control group of 20 healthy subjects who were matched for age, gender, and educational level.

Results: Treatment with doses of 2 and 4 mg of risperidone daily significantly reduced positive (p < .0001) and negative (p < .01) symptoms at 8 weeks. Although there were no significant differences in motor movements as measured using the Barnes Akathisia Scale and the Simpson-Angus Scale, computerized fine motor assessment showed significantly less motor dysfunction in the 2-mg/day group at 8 weeks. No significant correlations to plasma concentration of active moiety were found for data on psychopathology and fine motor functions.

Conclusion: The 2 doses of risperidone did not differ in terms of clinical improvement, but the 2-mg/day dose produced fewer fine motor dysfunctions. These results suggest that a dose as low as 2 mg/day of risperidone may be effective for patients with first-episode psychosis.