Current topics in tardive dyskinesia in Japan.

This article reviews current topics in tardive dyskinesia (TD), a movement disorder associated with the prolonged use of neuroleptic agents, especially therapeutic and preventive strategies which have been or are now being studied in Japan. Tardive dyskinesia has become a major problem in the clinical psychiatric field since the early 1970s in Japan, lagging behind Western countries by more than 10 years. The average prevalence rate of TD has been estimated as 7.7% in Japan, while it has been reported in the English literature at around 15 to 20%. Clinical trials of treatments for TD have been or are now being performed in Japan with a number of novel compounds, such as ceruletide, meclofenoxate, and rolipram; however, no effective treatment has yet been established and measures to prevent TD have therefore been emphasized. These include (i) the development of new antipsychotic drugs which are free from TD, (ii) the identification of risk factors from prospective longitudinal studies, and (iii) the investigation of genetic variations that could act as a marker to identify especially vulnerable patients within the whole population of patients who need neuroleptic therapy.