Epidemiology of Alzheimer’s disease and other dementias: rising global burden and forecasted trends

Background: The burden associated with Alzheimer’s disease is recognized as one of the most pressing issues in healthcare. This study aimed to examine the global and regional burden of Alzheimer’s disease and related dementias. Methods: Epidemiological data from the latest Global Burden of Disease (GBD) dataset were analysed to determine the prevalence, incidence and mortality rates from 1990 to 2019 for 204 countries and world regions. This dataset derives estimates for health metrics by collating primary data from research studies, disease registries and government reports. Temporal forecasting was conducted using the GBD Foresight tool. Results: An estimated 0.7% of the global population has dementia, translating to 51.6 million people worldwide. The total number of persons affected has more than doubled from 1990 to 2019. Dementia metrics showed a continuous increase in prevalence, incidence, mortality, and disability adjusted life years (DALYs) rates worldwide during the last three decades. Japan has the highest prevalence (3,079 cases per 100,000), followed by Italy, Slovenia, Monaco, Greece and Germany. The prevalence is higher in high-income regions such as Western Europe compared to Asia and Africa. However, total number of affected individuals is substantial in South and East Asian regions, in particular China, Japan and India. Dementia related deaths are projected to increase from the current 2.4 million per year to 5.8 million by 2040. Women are more likely to be affected by dementia than men. Age-standardized rates have not changed indicating possible stability of risk factors. Conclusions: Alzheimer’s disease and other dementias are rising rapidly and will more than double in mortality burden over the next 20 years. The tremendous burden in high- and middle-income countries can potentially overwhelm communities and health systems. Urgent measures are needed to allocate funding and provide residential care for affected persons.