Yokukansan, a traditional Japanese medicine (kampo) used to treat behavioral and psychological symptoms of dementia, was studied by researchers from the University of Tsukuba, in Ibaraki, Japan.

First, the details.

  • 106 patients with Alzheimer’s disease or dementia with Lewy bodies (abnormal proteins in nerve cells) were randomly assigned to a treatment group for 8 weeks.
    • Yokukansan for 4 weeks, then no treatment for 4 weeks.
    • No treatment for 4 weeks, then yokukansan for 4 weeks.
  • Changes in dementia were evaluated using the Neuropsychiatric Inventory (NPI) and the Mini-Mental State Examination (MMSE).
    • NPI assesses behaviors commonly observed in patients with dementia.
    • MMSE permits ongoing assessment of changes in cognition (reasoning).
  • Activities of daily living were also evaluated.

And, the results.

  • With yokukansan there was significant improvement in NPI scores regardless if taken during the first or second 4-week period.
  • There was no improvement during no treatment.
  • The difference in NPI scores between yokukansan and no treatment was significant.
  • Significant improvements with yokukansan were observed in delusions, hallucinations, agitation/aggression, depression, anxiety, and irritability/lability.
  • The effects of yokukansan persisted for 1 month without symptoms of psychological withdrawal.
  • Yokukansan had no effect on cognitive function or activities of daily living.
  • No serious side effects were observed.

The bottom line?
Yokukansan is also known as Yi-gan san in Chinese. It contains Atractylodes lancea rhizome, Poria sclerotium, Uncaria hook, Cnidium rhizome, Japanese Angelica root, Bupleurum root, and Glycyrrhiza.

In another study, where yokukansan was compared to placebo and the researchers were not aware of the treatment given, significant improvement in NPI and activities of daily living were reported.

A study in rats suggests that yokukansan is involved in controlling excitatory neurotransmitters.

6/21/09 18:21 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at www.Vicus.com, a complementary and alternative medicine website.