Global Prevalence of Alzheimer's Disease Set to Double Every 20 Years
By Pauline Anderson
Medscape Medical News
September 24, 2009 — The worldwide prevalence of Alzheimer's disease and other dementias will rise dramatically during the next 40 years, and the effect on families, governments, and healthcare systems will be immense, according to a new report.
The 2009 World Alzheimer Report, released by Alzheimer's Disease International, a nonprofit federation of 71 national Alzheimer organizations, estimates that the global prevalence of dementia, predicted to be more than 35 million in 2010, will almost double every 20 years to 65.7 million in 2030 and 115.4 million in 2050.
Based on a systematic review of 147 studies, the report represents a call for governments around the world to make dementia a priority, to collaborate on research, and to coordinate service distribution.
"The next step in the developed world, in countries like the United States, Canada, and Europe, is to convince our governments to invest more in Alzheimer's disease or Alzheimer's-related dementia — to invest more in research and in support systems," Remi Quirion, PhD, executive director, International Collaborative Research Strategy for Alzheimer's Disease, and professor, Department of Psychiatry, McGill University, Montreal, Canada, said in an interview.
"Developing countries should do that as well, but they should first make sure that everyone is aware that Alzheimer's disease is a real disease — it's not just a consequence of normal aging," Dr. Quirion added.
Low- and Middle-Income Countries
The projected prevalence of 35 million patients with Alzheimer's disease in 2010 represents a 10% increase over previous estimates reported in a 2005 Alzheimer's Disease International study published in The Lancet. Much of this increase is to the result of new data from low- and middle-income countries in parts of Asia, Africa, and South America.
According to the report, 57.7% of individuals with dementia worldwide live in low- and middle-income countries, but this percentage will rise to 70.5% by 2050. Forecasted growth figures for East Asia are 117% and 107% for South Asia, 134% to 146% in parts of Latin America, and 125% in North Africa and the Middle East. The report also forecasts an increase of 40% in the number of people with dementia in Europe, 63% in North America, 77% in southern Latin America, and 89% in the developed Asia Pacific countries.
Increased figures for low- and middle-income countries are partly explained by longer life expectancy in these regions as a result of better healthcare and the elimination of infectious diseases, said John M. Ringman, MD, assistant director, Mary S. Easton Center for Alzheimer's Disease Research, and associate clinical professor, Department of Neurology, University of California–Los Angeles.
"The prevalence is increasing because the population is aging and people are living to an older age, but also because people are more aware of the illness and we are becoming better able to identify who is demented and who is not in these countries," he said.
Emotional and Financial Impact
The report outlines the emotional and financial impact of dementia on patients and their families, on the healthcare system, and on society in general. An estimated 40% to 75% of caregivers have significant psychological illness, and 15% to 32% have clinically diagnosable major depression. The economic cost of dementia across the globe is estimated at $315 billion annually.
Unlike with some diseases, patients with Alzheimer's disease may live 10 or 15 years after diagnosis, so the effect on families can be huge, said Dr. Quirion. In some societies, the burden may be particularly heavy. For example, in China, where there is a government-mandated one family, one child policy, some of those parents are now developing Alzheimer's disease, and their only child may be called on to be the caregiver.
The report outlines 8 recommendations as part of a global framework for action on dementia. For Dr. Ringman, one of the most important recommendations is to ensure access to services for people with dementia regardless of age, sex, wealth, disability, or place of residence. He said he sees people from rural areas who come to his tertiary care center with "horrible dementias" that might be better treated if services were available closer to their home.
"That's a tall order, but it's important because this disease has an impact on rural communities as much as urban communities, and to be able to provide services to help out families in all these regions should be a priority."
As well, he said, language should not be a barrier to healthcare. "It's very hard to assess patients' cognitive status without being able to speak their language."
Fund More Research
Another recommendation — to fund and conduct more research into prevention and treatment for dementia, as well as its prevalence and impact — is also important, said Dr. Ringman. "If you could actually prevent the disease or treat it better, then a lot of the other recommendations are less necessary."
Dr. Quirion agreed that collaborative research efforts are a huge priority. "We have to have more investment into research, whether it's on genetics or quality of life. And we should do it at the global level — not necessarily Canadian scientists working in Canada, but Canadian scientists working and networking with the rest of the world."
Dr. Quirion also believes that countries, especially developing nations that may be dealing with issues related to dementia for the first time, should try to reduce the stigma surrounding this disease.
Other report recommendations include that:
the World Health Organization declare dementia a health priority;
national governments declare dementia a health priority and develop national strategies to provide services and support for people with dementia and their families;
low- and medium-income countries create dementia strategies based first on enhancing primary healthcare and other community services;
high-income countries develop national dementia action plans with designated resource allocations;
services be developed that reflect the progressive nature of dementia; and
collaborations among governments, people with dementia, caregivers, Alzheimer's associations, other relevant nongovernmental organizations, and professional healthcare bodies be created.
The authors have disclosed no relevant financial relationships.
