The research, led by scientists at the Centre for Healthy Brain Ageing (CHeBA) at the University of New South Wales (UNSW Sydney), estimated that 11.4 million people developed dementia globally in 2023.

The findings are based on an analysis of data from 38,418 participants across 22 population-based studies covering 18 countries and territories on six continents. The research provides updated estimates of how frequently dementia develops and highlights differences across populations.

The study found that dementia incidence was higher among women than men. After adjusting for age, the rate stood at 10.6 new cases per 1,000 person-years among women, compared with 8.6 among men.


Researchers also identified a significant difference between countries according to income level. Low- and middle-income countries recorded an estimated 13.6 new cases per 1,000 person-years, compared with 8.3 in high-income countries.

The researchers said the findings were particularly important because many low- and middle-income countries face growing populations of older people while having fewer resources available for dementia prevention, diagnosis and care.

Senior author Professor Perminder Sachdev, Co-Director of CHeBA, highlighted concerns about the burden on countries with limited healthcare resources. However, the study did not establish a single cause for the differences between men and women or between countries at different income levels.


The researchers noted that a range of health, social, economic, educational and environmental factors could contribute to the observed differences, although further research is needed to understand their individual effects.

Dementia is a syndrome involving a decline in memory, thinking and other cognitive abilities severe enough to interfere with everyday activities. It can result from several diseases, with Alzheimer’s disease being the most common cause.


Although it is more common among older people, dementia is not an inevitable part of ageing. The World Health Organization estimated that approximately 57 million people were living with dementia worldwide in 2021, with more than 60 per cent living in low- and middle-income countries. Previous research has projected that the global number of people living with dementia could rise to around 150 million by 2050.


The new study focuses on incidence, which measures the number of new cases developing over a period, rather than prevalence, which counts the total number of people living with the condition. The projected 24.7 million annual cases by 2050 should therefore not be confused with the total number of people expected to have dementia at that time.


The researchers said the findings could help governments and healthcare systems plan for future demand for diagnosis, treatment, long-term care and support for families. The estimates also underline the importance of improving dementia services in regions that have historically been underrepresented in international research.


The projections assume that age-specific and sex-specific incidence rates remain constant over time. Actual future figures could differ as populations change and prevention, healthcare access and other relevant conditions evolve.

The findings add to growing concerns about the worldwide impact of dementia and the need for better research, early diagnosis and adequate support for affected individuals and their families.


Reporting by TalkNaijaMedia