Abstract
Yokukansan, one of the Kampo prescriptions, is composed of seven herbaceous plants and was developed in China in the 16th century as a cure for restlessness and agitation in children. Yokukansan has also become a popular drug combination in Japan, especially for the behavioral and psychiatric symptoms of dementia (BPSD). Recent studies have shown that yokukansan might also be quite effective against BPSD occurring in association with other types of dementia, such as Alzheimer's disease, Lewy body disease, Parkinson's disease with dementia, frontotemporal dementia, and vascular dementia. Researchers have intensively investigated yokukansan, focusing on the pharmacological mechanisms against glutamate-mediated excitotoxicity. This traditional Chinese and Japanese medicine holds potential promise for improving BPSD in elderly patients suffering from dementia.