Background: The rapid increase in the elderly population in Japan has triggered a debate on whether or not patients with dementia should be informed of their diagnosis. The purpose of the present study was to investigate the attitudes of people in a large city in Japan toward the disclosure of a diagnosis of dementia.

Methods: In Study 1, 2000 residents aged 40–64 and 5000 residents aged 65 and over were sampled randomly, and a structured questionnaire was sent to them by mail. In Study 2, we administered a structured interview-based questionnaire to 3949 randomly enrolled residents of Nagoya City aged 45 and over whose family member had been certified as needing long-term care.

Results: In Study 1, 79.8% of the younger respondents (n = 710) stated that they would prefer the disclosure of a hypothetical diagnosis of dementia, as did 75.5% of the older respondents (n = 2162). Furthermore, 85.1% (n = 749) of the younger respondents and 82.5% (n = 2181) of the older respondents stated that they would prefer that the patient be told his or her hypothetical diagnosis of dementia. In Study 2, in the case of care recipients without dementia, 68.3% (n = 650) of their family members preferred disclosure of a hypothetical diagnosis of dementia. Among the families of care recipients who had dementia, 58.4% (n = 301) of family members preferred disclosure.

Conclusions: The present survey of caregivers and non-caregivers in an urban city of Japan demonstrated that the desire for disclosure of a diagnosis of dementia is relatively high.