The World Alzheimer Report,1 recently published under the auspices of Alzheimer Disease International (ADI), emphasises that, with global increases in population size and life expectancy, Alzheimer's disease (AD) has become a world health problem. According to the new report, the global prevalence of AD is set to rise to more than 35 million people by 2010, a 10% increase on the previous estimate published in 2005 by ADI.2 Moreover, the ADI investigators predict that dementia prevalence will nearly double every 20 years, to 65·7 million in 2030 and 115·4 million in 2050, and that the increases in prevalence have been mainly driven by new data from low-income and middle-income countries.