Extrapyramidal symptoms are independent of dosage or duration of therapy and depend instead on individual susceptibility to this drug, women apparently being more likely than men to develop extrapyramidal syndromes. The fairly large doses used in this study probably help explain the rather high incidence of these symptoms.In this pilot study, trifluoperazine proved to be a potent tranquilizer; it acted rapidly and was effective in smaller dosages than chlorpromazine. As with other tranquilizing agents, it affected behavior more than the underlying psychotic process. The lack of drowsiness made it easier for the therapist to approach the trifluoperazine-treated patient. Our experience indicated that trifluoperazine is effective in the management of chronic catatonic schizophrenia and chronic undifferentiated schizophrenia; it seems to activate lethargic, vegetative patients whose behavior is characterized by psychomotor retardation and apathy.Abstract Teaser