Amisulpride, a substituted benzamide with high selectivity for dopamine D3 and D2 receptors, was compared with the antipsychotic risperidone in patients with acute exacerbations of schizophrenia. The study was double-blind and involved 228 patients allocated, after a 3-6-day wash-out period, to amisulpride 800 mg (n = 115) or risperidone 8 mg (n = 113) for 8 weeks. Both treatments produced a marked improvement in schizophrenic symptomatology. Decreases in mean BPRS total score were 17.7 +/- 14.9 for amisulpride and 15.2 +/- 13.9 for risperidone, and all of the individual factors on the BPRS showed a numerically greater improvement in the amisulpride than in the risperidone patients. Both treatments were equally effective against positive symptoms on the PANSS positive syndrome subscale; however, there was a trend in favor of greater improvement in negative symptoms assessed on the PANSS negative subscale in patients receiving amisulpride with a decrease of 6.9 +/- 7.5 vs. 5.3 +/- 6.6 for risperidone (P = 0.09). Both drugs demonstrated good safety profiles, and scores on neurological scales (SAS, AIMS, and BAS) did not increase during treatment. A comparable proportion of patients received antiparkinsonian medication, 30 and 23% in the amisulpride and risperidone groups, respectively (P = 0.21). Patients receiving risperidone experienced an increase in body weight, which was significantly greater than for amisulpride (P = 0.026).