In recent years, elderly patients with dementia have been increasing in Japan. It is currently estimated that behavioral and psychological symptoms of dementia (BPSD) occur in approximately 80% of the elderly patients with dementia. As BPSD occur more frequently in elderly patients with dementia, the caregivers burden increases. Although non-pharmacological interventions can reduce BPSD in patients with dementia, antipsychotic medications have been used to treat severe BPSD. Physicians should be particularly careful in the use of antipsychotic medications in the elderly, which have been associated with dangerous adverse effects. Donepesil not only improves the cognitive dysfunction of Alzheimer disease patients, but may also relieve BPSD in these patients. Moreover, the effects on BPSD of yokukan-san, Kampo medicine, have been reported in elderly patients with dementia. A multicenter randomized crossover study, which we participated in, confirmed that yokukan-san is effective in the treatment of BPSD and that no rebound related deterioration occur after withdrawal of yokukan-san. The effects of yokukan-san on BPSD have been reported to influence gamma-amino-n-butyric acid and serotonin receptors.