A prospective study of tardive dyskinesia in Japan.

A large-scale, prospective study of tardive dyskinesia (TD) was performed in 11 psychiatric facilities in Japan. A total of 1595 psychiatric patients were enrolled in this study in 1987. The progress of these patients, with the exception of 490 dropouts, has now been followed up to 1988. The prevalence of TD at study entry was 7.6%, the annual incidence rate was 3.7% and the annual remission rate was 28.7%. Newly developed TD patients tended to be older, to have undergone more psychosurgery, and to have had lower neuroleptic doses than the patients who had not developed TD, whereas no specific variable could be detected as a factor associated with remission of TD. The results suggest that the incidence of TD is lower in Japan than that in Europe and North America.