We investigated the efficacy of nilvadipine, a calcium channel inhibitor, for psychiatric symptoms and tardive dyskinesia in 30 patients with chronic schizophrenia in a placebo-controlled double-blind crossover study. The total scores of the Brief Psychiatric Rating Scale decreased significantly when the patients were on nilvadipine compared with placebo. Improvement was particularly significant in emotional withdrawal and uncooperativeness. Nilvadipine was not effective, however, for tardive dyskinesia. No adverse effects, such as hypotension, occurred. (J Clin Psychopharmacol 1996;16:437-439).