GLOBAL dementia incidence is projected to more than double by 2050, reaching 24.7 million new cases annually, according to a meta-analysis of population-based studies. The researchers estimated 11.4 million new cases worldwide in 2023, highlighting differences by sex and country income level.
The analysis included individual participant data from 38,418 people across 22 longitudinal cohorts spanning 18 countries or territories on six continents. The cohorts formed part of the Cohort Studies of Memory in an International Consortium (COSMIC), with baseline recruitment between 1990 and 2011 and follow-up data collected through 2021.
Across 287,632 person-years at risk, 3,001 participants developed dementia. The age- and sex-standardised incidence was 9.7 cases per 1,000 person-years at risk (95% confidence interval [CI]: 7.89–11.97). Researchers used clinically based dementia diagnoses and harmonised statistical methods to generate comparable estimates across settings.
Age-standardised dementia incidence was higher among women than men. Rates were estimated at 10.6 cases per 1,000 person-years among women (95% CI: 8.61–13.11), compared with 8.6 among men (95% CI: 6.94–10.72).
Differences were also observed by country income level. Standardised incidence in low- and middle-income countries was 13.6 cases per 1,000 person-years (95% CI: 9.67–19.24), compared with 8.3 in high-income countries (95% CI: 6.57–10.54).
The authors noted that global dementia estimates have been limited by the underrepresentation of low- and middle-income countries and differences in analytical methods. Including data from diverse settings aimed to address these gaps and provide a more comparable picture of dementia incidence worldwide.
To estimate future cases, researchers applied age- and sex-specific incidence rates to the projected global population in 2050. This approach yielded an estimate of 24.7 million new dementia cases in that year, assuming incidence rates remain constant over time.
The projection is therefore conditional rather than a prediction of how incidence will change. The findings nevertheless provide a benchmark for planning prevention strategies, diagnostic services, and memory care, particularly in countries that have been underrepresented in previous research.
The authors concluded that these harmonised estimates offer insights into current and future dementia incidence and reinforce the importance of improving evidence from low- and middle-income settings.
Reference
Vella AS et al. Global incidence of all-cause dementia: a meta-analysis. JAMA Neurol. 2026;DOI:10.1001/jamaneurol.2026.3540.
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