&NA;Perospirone (SM 9018), a novel serotonin 5-HT2and dopamine D2receptor antagonist, is currently undergoing phase III clinical trials with Sumitomo in Japan as a potential antipsychotic agent. Perospirone has only weak cataleptogenic and central depressant effects in animals. Perospirone has a profile of activity suggesting beneficial effects on both the positive and negative symptoms of schizophrenia. Perospirone is also undergoing phase II trials for cerebrovascular dementia in Japan.