Abstract Background: The author started to engage in research, clinical practice, and education in geriatric psychiatry as a professor at the Department of Psychiatry, Osaka University, from 1996 to 2015, during which time I was active in the Japanese Psychogeriatric Society (JPS) and the International Psychogeriatric Association (IPA). Building on this experience, I continued to do research to elucidate the nature of cognitive reserve and the characteristics of centenarians in Japan, even after moving to Osaka Kawasaki Rehabilitation University. Methods: In this review, I used the data about the histories of the Department of Psychiatry at Osaka University, the JPS, the IPA, and the published materials. I used data on centenarians, healthcare workers, and patients with dementia, fractures, and dental caries by prefecture that were cited from the author’s papers and analyzed data released by the Ministry of Health, Labor, and Welfare of Japan. Results: Japan’s centenarian population, 99,736 in 2025, is expected to continue increasing. Approaches for these centenarians require different strategies than those used for the elderly aged 65 and over. While the JPS has historically focused on mental health for the elderly, this study indicates that new approaches tailored to centenarians are necessary, based on past experience. Conclusion: Japan’s centenarian population will continue to grow, with an estimated one-third to one-half of those born after 2000 expected to reach 100 years of age. Achieving this requires not only avoiding physical illnesses such as dementia, fractures, and dental caries but also actively improving food consumption habits and overall lifestyle.
Masatoshi Takeda (Thu,) studied this question.