Global Dementia Cases Projected to Double by 2050
Key Clinical Summary
- A meta-analysis of 38,418 participants across 18 countries or territories estimated 11.4 million new dementia cases globally in 2023, with annual incidence projected to reach 24.7 million by 2050.
- Age-standardized dementia incidence was higher among women than men, at 10.6 versus 8.6 cases per 1000 person-years.
- Low- and middle-income countries had higher standardized incidence than high-income countries, highlighting disparities relevant to global dementia care planning.
An estimated 11.4 million new cases of dementia occurred worldwide in 2023, with annual incidence projected to increase to 24.7 million by 2050, according to a meta-analysis of international longitudinal cohort data published in JAMA Neurology. The findings also identified higher incidence among women and in low- and middle-income countries, underscoring differences in the global burden of dementia.
Study Findings
Researchers analyzed individual participant data from 22 population-based longitudinal cohorts participating in the Cohort Studies of Memory in an International Consortium (COSMIC). The analysis included 38,418 participants across 18 countries or territories spanning 6 continents.
Baseline recruitment occurred between 1990 and 2011, with follow-up data collected through 2021. Eligible cohorts used clinically based dementia diagnoses, and researchers standardized incidence estimates to the 2023 global age-sex population structure.
Over 287,632 person-years at risk, a total of 3001 participants developed dementia. The global age- and sex-standardized incidence rate was 9.7 cases per 1000 person-years (95% CI, 7.89-11.97).
Age-standardized incidence was higher among women than men, at 10.6 versus 8.6 cases per 1000 person-years, respectively. Incidence was also higher in low- and middle-income countries than in high-income countries, at 13.6 versus 8.3 cases per 1000 person-years.
The researchers also applied age- and sex-specific incidence rates to projected population figures for 2050, which yielded an estimated 24.7 million new dementia cases annually, more than double the estimated 11.4 million in 2023. This projection assumed that incidence rates remain constant over time.
Clinical Implications
According to the authors, the findings provide a standardized benchmark for understanding global dementia incidence and anticipating future demand for diagnostic services, prevention initiatives, and memory care. Previous global estimates have been limited by inconsistent analytic methods and underrepresentation of lower-income settings. By harmonizing individual participant data across international cohorts, this study offers more comparable estimates of dementia incidence across populations.
The higher incidence observed among women and in low- and middle-income countries also highlights specific populations that may warrant particular attention in future research and healthcare planning.
However, the projected increase in annual cases reflects anticipated demographic changes under an assumption of constant incidence, rather than a demonstrated increase in individual dementia risk.
Expert Commentary
“The observed sex- and income-stratified differences, together with substantial cross-country variation, highlight the need for targeted equitable prevention strategies and expanded diagnostic and care capacity, particularly for women and in underresourced settings,” wrote Ashleigh S. Vella, PhD, Centre for Healthy Brain Ageing, Discipline of Psychiatry & Mental Health, School of Clinical Medicine, University of New South Wales, Sydney, New South Wales, Australia, and coauthors.
The investigators concluded that their harmonized estimates may be used to strengthen prevention, diagnosis, and memory-care services across patient populations.
