antipsychotic drug

n. Any of numerous drugs used to treat schizophrenia, delusional disorder, mania, deliria, and other extreme thought disorders and behavioral bizarreness or agitation. This class of drugs includes drugs developed in the middle of the 20th century called typical antipsychotics, such as the phenothiaz- ines, butyrophenones, and thioxanthenes. Newer antipsychotic drugs are called atypical antipsychotics; they include clozapine, which has negative effects on the immune system, and more recently olanzapine, risperidone, quetapine, ziprasidone, and aripiprazole.