Dementia Crisis: Global New Cases to Hit 24.7 Million Annually by 2050

An estimated 11.4 million people worldwide developed dementia in 2023, with the number of new cases projected to rise to 24.7 million annually by 2050, according to a landmark Australian-led international study that provides the most comprehensive global benchmark yet for understanding the disease's accelerating burden.

The research, led by the Centre for Healthy Brain Ageing (CHeBA) at the University of New South Wales in Sydney, analysed data from 38,418 people across 22 population-based studies in 18 countries and territories spanning six continents. Published in JAMA Neurology, the study found that dementia incidence was significantly higher among women than men and substantially higher in low- and middle-income countries than in high-income nations. Across more than 287,000 person-years of follow-up, 3,001 participants developed dementia.

The findings reveal stark disparities in who is developing the disease. After accounting for age, the global standardised incidence rate was 9.7 new cases per 1,000 person-years. Women recorded 10.6 cases per 1,000 person-years compared with 8.6 among men, while low- and middle-income countries recorded 13.6 cases per 1,000 person-years compared with just 8.3 in high-income countries. The researchers noted that the difference by income level was even greater than the disparity between sexes. Dementia currently affects more than 57 million people worldwide, with previous research projecting the number of people living with the condition to reach about 150 million by 2050.

Senior author and CHeBA Co-Director Professor Perminder Sachdev described the higher incidence in low- and middle-income countries as particularly concerning. "These regions are experiencing rapid population ageing while often having the fewest resources for prevention, diagnosis and care," he warned. Lead author Dr Ashleigh Vella stressed that understanding these differences is critical for developing prevention, diagnosis and care strategies that respond to the populations facing the greatest future risk. "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," she said.

The study's projections carry profound implications for health systems worldwide. CHeBA Co-Director Professor Henry Brodaty, the 2026 Senior Australian of the Year, said 24 million new cases annually would place enormous pressure on individuals, families, health systems and economies. "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," he said.

The research reinforces the findings of the World Health Organisation's 2026 guidelines, which estimate that up to 45 per cent of dementia risk can be attributed to modifiable factors such as tobacco use, alcohol consumption, social isolation, physical inactivity, air pollution, and noncommunicable diseases including high blood pressure, diabetes and high cholesterol. The WHO has projected that global dementia cases will surpass 139 million by 2050, with more than 60 per cent of people living with dementia currently in low- and middle-income countries—a share expected to rise above 70 per cent by 2050.

For Nigeria, the implications are particularly severe. With a population exceeding 260 million and an ageing demographic, the country is already grappling with a rising dementia burden. Approximately 4.9 per cent of Nigerian adults aged 60 and above live with dementia, translating to over one million affected individuals nationwide. Alzheimer's Disease International estimates that Nigeria's dementia cases will increase by 387 per cent by 2050, with over 1.4 million Nigerians projected to be living with the condition. A 2026 warning from a University College Hospital neurologist noted that about 20 million Nigerians are already at risk of developing dementia, given that between eight and ten per cent of the population—approximately 20 million people—are aged 60 and above.

The study's lead author, Dr Vella, emphasised that understanding the differences in incidence is critical for developing effective prevention and care strategies. The researchers highlighted that higher rates among women may be influenced not only by longer life expectancy but also by factors including menopause, unequal educational and occupational opportunities, and higher rates of depression, anxiety and obesity. Professor Brodaty noted that people in more complex occupations have a lower rate of cognitive decline, and that education—particularly in childhood and early development—can build a cognitive reserve that buffers against pathology throughout life.

The economic toll of dementia is equally staggering. The WHO estimates that dementia costs the global economy approximately $1.3 trillion annually, with about half of that cost driven by unpaid care provided by families and friends. As the number of people living with dementia continues to rise, particularly in countries with limited health infrastructure, the financial and human costs will intensify, placing unprecedented strain on caregivers, communities and governments.

Despite the alarming projections, the research also offers a message of hope. The finding that nearly half of all dementia cases could be prevented or delayed through lifestyle modifications has galvanised calls for greater investment in prevention and early intervention. As Professor Brodaty urged, "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." For Nigeria and other low- and middle-income countries, the challenge is enormous but not insurmountable. With the right policies, investments and public awareness, the coming dementia epidemic could be mitigated. But the window for action is narrowing, and the cost of inaction will be measured in millions of lives.