The World Health Organization says nearly 140 million people worldwide will live with dementia in 2050. That is roughly 2.5 times the figure for 2019.
The estimate was included in the WHO's "Global status report on the public health response to dementia," which was released on Thursday.
The report says 55.2 million people around the world had dementia in 2019, accounting for 6.9 percent of those aged 65 years or older.
The report projects that the number will swell to about 78 million in 2030, and roughly 139 million in 2050 because of expected population aging.
The WHO says the world is failing to address the challenge of dementia. It adds "Only a quarter of countries worldwide have a national policy, strategy or plan for supporting people with dementia and their families."
WHO Director-General Tedros Adhanom Ghebreyesus said concerted action is needed ''to ensure that all people with dementia are able to live with the support and dignity they deserve."