Background: Recent studies indicate that the traditional Japanese herbal medicine yi-gan san (YGS, yokukan-san in Japanese), a serotonin modulator, may be safe and useful in treating behavioral and psychological symptoms in dementia and borderline personality disorder patients. The authors examined the efficacy, tolerability, and safety of YGS in patients with tardive dyskinesia.
Methods: Twenty-two patients with schizophrenia who had neuroleptic-induced tardive dyskinesia were given 7.5 g/day of YGS for 12 weeks in an open-label study.
Results: Administration of YGS resulted in a statistically significant improvement in tardive dyskinesia and psychotic symptoms.
Conclusions: YGS may be an effective and safe therapy to control tardive dyskinesia and psychosis in patients with schizophrenia, that should be further tested in double-blind, placebo-controlled trials.