antipsychotic /-sīkot″ik/ [Gk, anti + psyche, mind, osis, condition] , 1. pertaining to a substance or procedure that counteracts or diminishes symptoms of a psychosis. 2. an antipsychotic drug. Categories include the phenothiazine derivatives, butyrophenones, thioxanthene derivatives, dibenzodiazepines, diphenylbutylpiperidines, dihydroindolones, and dibenzoxazepines. They are chemically diverse but pharmacologically similar. Formerly called major tranquilizer.
