Global dementia study reveals 11.4 million new cases in 2023 - projected to more than double by 2050
Centre for Healthy Brain Ageing (CHeBA), UNSW Sydney
UNDER EMBARGO: 2.00am 13th October AEDT
Landmark international research has produced some of the most comprehensive and comparable estimates of new dementia cases worldwide, revealing an estimated 11.4 million people developed dementia in 2023 - a figure projected to rise to 24.7 million a year by 2050.
The study, published in JAMA Neurology, analysed data from 38,418 people across 22 population-based studies spanning 18 countries and territories on six continents.
Led by researchers from UNSW Sydney’s Centre for Healthy Brain Ageing (CHeBA) through the Cohort Studies of Memory in an International Consortium (COSMIC), the research provides a new global benchmark for understanding how frequently new cases of dementia are occurring across different populations.
Importantly, the study found dementia incidence was higher among women than men, and substantially higher in low- and middle-income countries (LMICs) than in high-income countries.
Across more than 287,000 person-years of follow-up, 3,001 participants developed dementia. The global age- and sex-standardised incidence rate was 9.7 new cases per 1,000 person-years. After accounting for age, incidence was higher among women, at 10.6 cases per 1,000 person-years, compared with 8.6 among men.
The difference between countries by income level was even greater. Standardised incidence was 13.6 cases per 1,000 person-years in LMICs, compared with 8.3 in high-income countries.
A clearer picture of who is developing dementia
Dementia currently affects more than 57 million people worldwide, with previous research projecting prevalence to reach approximately 150 million by 2050. Yet much of what is known about dementia has historically come from high-income countries, despite some of the greatest future increases being expected in lower-resource settings.
The new research focuses specifically on incidence – the rate at which people develop dementia or the number of new cases per year – rather than prevalence, which measures the total number of people living with the condition at a given time.
Understanding incidence is critical for governments and health systems because it helps anticipate future demand for diagnosis, clinical care and support services, while informing where prevention efforts may have the greatest impact.
Lead author Dr Ashleigh Vella, Post-Doctoral Research Fellow at CHeBA, said the findings provided an important new benchmark for understanding the changing global dementia landscape.
“For the first time, we can compare dementia incidence across a geographically diverse group of populations using the same statistical approach, giving us a clearer picture of where and among whom new cases are occurring.”
“What stands out is that dementia incidence is not evenly distributed. We see higher rates among women and in low- and middle-income countries.
“Understanding these differences is critical if we are to develop dementia prevention, diagnosis and care strategies that respond to the populations facing the greatest future risk.”
CHeBA Co-Director, co-author and 2026 Senior Australian of the Year Prof. Henry Brodaty said the findings reinforced the urgency of investing in dementia prevention.
“Twenty-four million new cases of dementia every year would place enormous pressure on individuals, families, health systems and economies around the world.
“Population ageing means we cannot simply wait for people to develop dementia and then respond. We need to act across the spectrum - from reducing modifiable risk factors and identifying people at risk earlier, through to improving diagnosis, treatment and care.
Addressing a major gap in global dementia research
Reliable international comparisons of dementia incidence have historically been difficult. Longitudinal studies capable of measuring new dementia cases are less common than studies estimating prevalence, particularly in LMICs, while differences in diagnostic and statistical approaches have further limited direct comparisons.
The study sought to overcome these limitations through COSMIC, an international CHeBA-led consortium combining data from longitudinal studies of ageing and memory around the world. The analysis drew on cohorts from 18 countries and territories – 6 LMICs and 12 high-income countries – with researchers applying consistent statistical methods and clinically based dementia diagnoses across the included studies.
Senior author and CHeBA Co-Director Prof. Perminder Sachdev said the higher incidence identified in LMICs was particularly important given where much of the future growth in dementia is expected to occur.
“The higher incidence we observed in low- and middle-income countries is particularly concerning because these regions are experiencing rapid population ageing while often having the fewest resources for prevention, diagnosis and care.
“Our findings highlight the urgent need to strengthen dementia risk reduction and health-care capacity globally, while investing in better local data so services can be planned according to the needs of individual countries.”
The researchers caution that the study does not establish why dementia incidence was higher among women or in LMICs. The differences may reflect a complex combination of health, social, economic, educational and environmental factors, and further research in diverse populations will be needed to understand what is driving them.
About COSMIC
The Cohort Studies of Memory in an International Consortium (COSMIC) is an international collaboration of longitudinal studies of ageing and memory coordinated through UNSW Sydney’s Centre for Healthy Brain Ageing (CHeBA). By bringing together participant-level data from studies around the world, COSMIC aims to improve understanding of cognitive ageing and dementia across diverse populations and geographical regions.
About CHeBA
The Centre for Healthy Brain Ageing (CHeBA) at UNSW Sydney is an international leader in research focused on preventing dementia, promoting healthy brain ageing and improving the lives of people living with dementia through research, innovation and collaboration.
Doi: 10.1001/jamaneurol.2026.3540
Contact details:
Heidi Douglass, Centre for Healthy Brain Ageing
T: (02) 9385 0410