Effects of Yoku-kan-san on undifferentiated somatoform disorder with tinnitus.

Up to the present, there have been few strategies that are completely effective in treating undifferentiated somatoform disorder with tinnitus. We herein report that Yoku-kan-san (TJ-54), one of Japan's traditional herbal medicines, is an effective treatment for tinnitus in undifferentiated somatoform disorder complicated with headache and insomnia. TJ-54 has been also used as an effective treatment for insomnia and irritability in recent centuries and is considered to have some effects on the excitability of nerves. Further studies are needed to confirm the efficacies of Japanese herbal medicines.