A Pilot Double-Blind, Dose-Comparison Study of Risperidone in Drug-Naive, First-Episode Schizophrenia

Letter to the Editor

Sir: The efficacy and safety of risperidone in patients with first-episode schizophrenia have been demonstrated in open trials and in controlled studies. However, the optimal dosing of risperidone for this population remains controversial. In the open trial by Kopala et al., low doses of 2 to 4 mg/day (N = 11) were associated with better outcome than high doses of 5 to 8mg/day (N = 11). Another small-scale open trial also reported similar findings. In the double-blind study by Emsley et al., the mean final daily dose of risperidone was 6.1 mg (N = 99) and that of haloperidol, 5.6 mg (N = 84). In another study, the mean daily dose was 4.2 mg for risperidone (N = 16) and 4.0 mg for haloperidol (N = 19). Recommendations for both low (2-4 mg/day) and higher (4-8 mg/day) doses are found in the literature. Of note, the previous trials are of limited value because they did not include random assignment to fixed doses of risperidone.