News Release

More Than 35 Million People Have Alzheimer's And Other Dementias Worldwide, According To New Report Released On World Alzheimer's Day

21 September 2009

  • 10 Percent Increase Over 2005 Estimate
  • Dementia Will Nearly Double Every 20 Years
  • Increases Driven By New Data From Low & Middle Income Countries

More than 35 million people worldwide will have dementia in 2010, according to the newly released 2009 World Alzheimer Report from Alzheimer's Disease International (ADI), a London-based, nonprofit, international federation of 71 national Alzheimer organizations. The new report was released on World Alzheimer's Day to raise awareness for this disease that will have a dramatic impact on individuals and healthcare systems globally.

This is a 10 percent increase over previous global dementia prevalence reported in an ADI study published in 2005 in The Lancet*. According to the new report, dementia prevalence will nearly double every 20 years, to 65.7 million in 2030 and 115.4 million in 2050.

According to the researchers, the increases in global dementia prevalence were driven primarily by new data from low and middle income countries. Estimates for three regions are higher - Western Europe, South Asia and Latin America than the 2005 estimates. The estimate for East Asia is lower. The estimate for North America, while slightly higher, is effectively identical.

"The information in the 2009 World Alzheimer Report makes it clear that the crisis of dementia and Alzheimer's disease cannot be ignored," said Marc Wortmann, ADI's Executive Director. "Unchecked, dementia and Alzheimer's will impose enormous burdens on individuals, families, health care infrastructures, and the worldwide economy."

"There is hope in taking action and raising awareness of dementia and Alzheimer's, to improve and fund dementia care and services and to increase investment in research," Wortmann said. "For example, Australia, France, Korea and the UK have developed and are implementing national Alzheimer's and dementia action plans, and several more are currently in development."

In addition to new prevalence estimates, the report outlines challenges faced by governments and health care systems worldwide to meet the needs of the growing numbers of people living with Alzheimer's and dementia, their families and caregivers (Chapter 3). The research team offers eight global recommendations based on report findings (Chapter 4, see attachment).

Dementia is a syndrome due to brain disease. It is usually chronic, and is characterized by a progressive, global deterioration in intellectual abilities, including memory, learning, orientation, language, comprehension, and judgment. Alzheimer's disease, in particular, is progressive and fatal. Dementia mainly affects older people, especially those over age 65. After this age, dementia prevalence doubles every five years. Dementia is one of the major causes of disability in late-life and is linked to a large number of underlying brain diseases. Alzheimer's is the most common cause of dementia; vascular dementia, dementia with Lewy bodies, and frontotemporal dementia are the next most common.

Prevalence Increases Driven By Low and Middle Income Countries

According to the 2009 World Alzheimer Report, much of the increase in dementia prevalence is clearly attributable to increases in the numbers of people with dementia in low and middle income countries. The researchers found that 57.7% of all people with dementia worldwide in 2010 live in low and middle income countries, rising to 70.5% by 2050.

In addition, proportionate increases over the next 20 years in the number of people with dementia will be much steeper in low and middle compared with high income countries. The report forecasts a 40% increase in numbers in Europe, 63% in North America, 77% in the southern Latin American cone and 89% in the developed Asia Pacific countries. These figures are to be compared with 117% growth in East Asia, 107% in South Asia, 134-146% in the rest of Latin America, and 125% in North Africa and the Middle East.

How This Report Was Prepared

Methodology used to prepare the 2009 World Alzheimer Report is explained in the full printed report and can be found online at

"This is a new systematic review of the global prevalence of dementia, based on 147 studies in 21 World Burden of Disease world regions," said Professor Martin Prince, MD, MSc, MRCPsych, Professor of Epidemiological Psychiatry at the Institute of Psychiatry in London, lead investigator for the report. "It is the most comprehensive global prevalence study of dementia to date."

The Emotional and Financial Impact of Dementia

Chapter 2 of the new report focuses on the impact of dementia. Dementia has physical, psychological and economic impact not only on the person with the disease, but also caregiver(s), the person's family and friends, healthcare system(s), and society. Caregivers of people with dementia are very likely to experience strain. Statistics cited in the new report suggest that 40-75% have significant psychological illness as a result of their caregiving, and 15-32% have clinically diagnosable major depression. There may also be physical health consequences; strained caregivers have impaired immunity and a higher mortality rate.

Worldwide, the economic cost of dementia has been estimated as US$315 billion annually. The total annual costs per person with dementia have been estimated as US$1,521 in a low income country, rising to US$4,588 in middle income countries, and US$17,964 in high income countries. (Anders Wimo, et al. "An Estimate of the Total Worldwide Societal Costs of Dementia in 2005." Alzheimer's & Dementia: The Journal of the Alzheimer's Association. Volume 3, Issue 2, April 2007.)

World Alzheimer's Day

September 21 is World Alzheimer's Day, when Alzheimer organizations worldwide work together to raise awareness of the disease. The theme for World Alzheimer's Day 2009 is "Diagnosing Dementia: See It Sooner."

Alzheimer's Disease International

Alzheimer's Disease International (ADI) is an international federation of 71 Alzheimer associations around the world, in official relations with the World Health Organization. Each member is the national Alzheimer association in their country that supports people with dementia and their families. ADI's mission is to improve the quality of life of people with dementia and their families throughout the world. Please visit

The 2005 Lancet article is: Ferri, Prince, et al. "World prevalence of dementia: a Delphi consensus study." Lancet. Vol. 366, December 17/24/31, 2005.