“…It has been approved by the Japanese Ministry of Health, Labour and Welfare as a treatment for neurosis, insomnia, and irritability in children. Recently, YKS was reported to reduce the behavioral and psychological symptoms of dementia (BPSD), including agitation, aggressiveness, and hallucinations, not only in patients with Alzheimer's disease (AD) [1][2][3] but also in those with dementia with Lewy bodies (DLB), 4,5) Parkinson's disease (PD), or PD with dementia (PDD), 6,7) which are characterized by progressive dopamine (DA) neuronal loss. These clinical findings suggested that YKS acts on the DA nerve system, but it does not show the extrapyramidal side effects of the typical or atypical antipsychotic drugs used in the treatment of BPSD, which have a DA D 2 receptor antagonistic effect.…”