Annual dementia cases could more than double by 2050, study projects

The number of people developing dementia worldwide each year could more than double, from 11.4 million in 2023 to 24.7 million by 2050, according to an international study published in “JAMA Neurology”.

The research analysed individual data from 38,418 participants in 22 population-based studies across 18 countries and territories on six continents. During more than 287,000 person-years of monitoring, 3,001 participants developed dementia.

Researchers calculated a global age- and sex-standardised incidence rate of 9.7 new cases per 1,000 person-years. Incidence measures the frequency of new cases, while prevalence refers to the number of people already living with a condition.

After accounting for age, the incidence rate was 10.6 cases per 1,000 person-years among women and 8.6 among men. The difference was greater between countries by income level: low- and middle-income countries recorded 13.6 cases per 1,000 person-years, compared with 8.3 in high-income countries.

Lead author Ashleigh Vella of the University of New South Wales’ Centre for Healthy Brain Ageing said the study enabled comparisons across geographically diverse populations using the same statistical approach. She said the results showed dementia incidence was not evenly distributed, with higher rates among women and in low- and middle-income countries.

The projection for 2050 was calculated by applying the study’s age- and sex-specific incidence rates to expected population figures. It assumes those rates remain constant, so the projected increase is driven largely by population growth and ageing.

The researchers said the findings could help governments plan for future demand for diagnosis, treatment, long-term care and support services, particularly in lower-resource countries that have been underrepresented in dementia research.

Dementia currently affects more than 57 million people worldwide. Previous research has projected that the number of people living with the condition could approach 150 million by 2050.

Study co-author Henry Brodaty said 24 million new cases a year would place “enormous pressure on individuals, families, health systems, and economies around the world.” He called for action to reduce modifiable risk factors, identify people at risk earlier and improve diagnosis, treatment and care.