New dementia cases could more than double to nearly 25 million a year by 2050, a 22-cohort analysis estimates

A meta-analysis published in JAMA Neurology and summarised by JAMA on 30 October 2026 estimates how many people develop dementia each year worldwide.

The study

• Patient-level data from 22 community-based cohorts.
• About 38,400 adults without dementia at the start, from 18 countries and territories.

Findings

• An estimated 11.4 million new cases of dementia in 2023.
• If age- and sex-specific rates stay the same, yearly new cases could reach nearly 25 million by 2050, as populations age.
• Women developed dementia more often: nearly 11 new cases per 1,000 women a year vs about 9 per 1,000 men.
• Rates were higher in low- and middle-income countries than in high-income ones: about 14 vs 8 new cases per 1,000 older adults.

The authors say the figures can help plan prevention, diagnosis and memory-care services, especially for women and in under-resourced settings.

Limitations

The 2050 figure is a projection that assumes today’s rates stay constant; real rates may fall (for example with better education and heart health) or rise. Data from low- and middle-income countries are still sparse, which the authors say needs fixing. This article is based on JAMA’s summary of the paper. If you are worried about memory changes, talk to your doctor.