A case of dose-dependent lithium-induced tardive dyskinesia.

Tardive dyskinesia (TD) is a serious side effect that manifests itself mainly with choreiform and athetotic movement disorders, and generally occurs in the long term during antipsychotic treatments and is generally irreversible. We report a 67-year-old female patient having a diagnosis of Bipolar Disorder (BD) for 25 years, receiving 1200 mg/day lithium monotherapy for 10 years and in remission. The patient had been showing signs of TD-like syndrome for the last 6 months. Because the patient responded to lithium well and because other treatment options for TD were unsuccessful, the lithium dose was reduced to 600 mg/day and the patient was monitored. Three months after the dose reduction, the patient's remission state continued, and the TD findings regressed. TD mainly due to antipsychotics is known as irreversible. This case suggests that lithium-induced TD may be reversible in a dose-dependent manner.