According to the latest forecasts of the INSEE - Institut National de la Statistique et des Etudes Economiques (National Statistics and Economic Studies Institute), ageing of the French population will increase between 2005 and 2050: whereas 20.8% of the population living in continental France reached the age of 60 years or more in 2005, this proportion would be of 30.6% in 2035 and 31.9% in 2050. In 2050, 22.3 million persons will have reached the age of 60 years or more compared to 12.6 million in 2005, increasing by 80% in a 45-year period. In line with the actual age pyramid, ageing is unavoidable, as those who will reach 60 years of age in 2050 are already born (in 1989 or before). This expansion will be most important between 2006 and 2035, when the numerous "baby-boom" generations born between 1946 and 1975, will reach these ages. In future years, lifespan improvement will only emphasize this increase. Even if life expectancy stabilizes at the 2005 level, the number of seniors reaching 60 years or more would still increase to 50% between 2005 and 2050. This issue is identical in all countries of the European Union. Ageing is a major risk factor for dementia that will considerably worsen in the next years, if no curative therapies are found. Today, 25 million persons in the world suffer from Alzheimer's disease (AD). In France, it is estimated that 860,000 persons are affected and that 225,000 news cases are annually diagnosed. After 75 years of age, more than 20% of women and 13% of men are concerned. Forecasts for the coming years are frightening. Considering ageing of the population, the number of Alzheimer's disease cases should raise to 1.3 million in 2020 (20 patients for 1000 inhabitants) ant 2.1 million in 2040 (30 patients for 1000 inhabitants).