Antipsychotics-Induced Tardive Syndrome: A Retrospective Epidemiological Study

Objectives: Only little information of the epidemiology of tardive syndrome in patients using antipsychotics is available. Herein, we aimed to investigate the prevalence and risk factors of antipsychotics-induced tardive syndrome. Methods: This study was conducted by means of a retrospective survey. Subjects receiving antipsychotics for more than 6 months, but no other agents that may cause involuntary movements, were consecutively recruited. Tardive syndrome was evaluated in every included subject. Possible confounding medical conditions were carefully ruled out. Results: Of the 123 included subjects, 35 (28.5%) were found to have at least 1 episode of tardive syndrome. The prevalence of subtypes of tardive syndrome were as follows: tardive dyskinesia, 21.1%; tardive dystonia, 12.5%; tardive tremor, 2.4%; and tardive akathisia, 2.4%. Concurrent physical illness and a history of extrapyramidal symptoms were significant risk factors for tardive syndrome. Conclusions: This study showed that antipsychotics may induce various types of tardive syndrome, of which tardive dyskinesia is the most predominant one. Physicians should be aware of this common and distressing adverse effect when using antipsychotics.