Tardive dyskinesia in elderly psychiatric patients in Singapore.

The prevalence of tardive dyskinesia (TD) in 514 psychiatric patients who were 60 years and above in Singapore was found to be 27.6%. This is low compared with other studies done on elderly psychiatric patients in the West. Among the different ethnic groups, the Eurasians have the highest prevalence of 53.8% compared to the Chinese, Malays or Indians. Inpatients have a higher prevalence (31.5%) than outpatients (10.5%). Higher prevalence was also found in women, who were 2.2 times more common than men. 50% of the mentally retarded patients were found to have TD.