TO THE EDITOR: We thank Drs. Capehart and Holsinger, Dr. Barbui, and Dr. Mattes for sharing their opinions. Capehart and Holsinger suggest that we combined patients from distinct diagnostic groups. However, only subjects with DSM-III-R schizophrenia or schizophreniform or schizoaffective disorder were randomly assigned to treatment. We do not feel that these diagnoses represent distinct groups. All three are classified by the DSM nomenclature under "schizophrenia and other psychotic disorders." Furthermore, ICD-10 includes schizophreniform disorder under schizophrenia, which underscores the diagnostic similarities. Moreover, 83% of the 1,996 patients had the specific diagnosis of schizophrenia. In addition, there was no statistically significant difference among diagnostic groups in efficacy or safety conclusions. Capehart and Holsinger's second point alludes to different severity levels. We assume that they are referring to baseline severity as defined by total score on the Positive and Negative Syndrome Scale. In our opinion, mean scores of 90.1 (olanzapine group) and 92.1 (haloperidol group) do not suggest a clinically relevant diversity in symptom severity. Furthermore, these baseline differences did not contribute to analytical differences in the statistical methods, e.g., analyses of covariance that used patients' baseline score as the covariate. Under those analyses, all measures of efficacy were statistically significant in favor of superior efficacy within the olanzapine group.