Validation of the Japanese version of the Social Functioning in Dementia scale and COVID-19 pandemic's impact on social function in mild cognitive impairment and mild dementia.

The SF-DEM-J is acceptable as a measure of social function in MCI and mild dementia. Our results show that the social functioning of people with dementia, especially communicating with others, improved during the COVID-19 pandemic, probably as a result of adaptation to the restrictive life.