To the Editor: Regarding the study by Jan Volavka, M.D., Ph.D., et al. (1), the authors should be commended for attempting to differentiate four different antipsychotics in a single trial. However, I believe that the conclusions reached in this study cannot be supported by the data. During the last 6 weeks of the trial, the dose was increased in all four treatment groups. Only the olanzapine group had greater efficacy as a result. Why was the dose increased in the other treatment groups if there was no further improvement? In the case of risperidone, this increase resulted in a mean dose of 11.6 mg/day. It has been well established that risperidone doses above 10 mg/day are less effective than lower doses (2). Thus, this study demonstrated that investigators are unable to optimize patient response using dose titration. An alternative design (e.g., with a fixed dose) should have been employed.