A singularity in gender difference in medicine: nervous system and behavior.

A symposium entitled "A singularity in gender difference in medicine: nervous system and behavior" was held on 21st March 2025 at the 85th Annual Meeting of the Japan Society for Hygiene in Saitama, Japan. Three speakers presented reviews on gender difference in neurodegenerative disease including Alzheimer disease and actions of sex steroid and regulation of their receptors, and one speaker presented an original study on gender difference in behavior of twins. The symposium concludes that further research is needed to clarify the roles of estrogen and genetic factors to better understand the mechanisms underlying gender differences in neurodegenerative diseases and behavioral problems.