[Update on Alzheimer's disease]

As the general population ages, the prevalence of Alzheimer's disease increases steadily. In France, 850,000 people are affected, with an annual incidence of 165,000 new cases. It is estimated that in 2020, 1.2 million people will be concerned in France. Nearly half of these patients, about 400,000, will have moderate to severe disease. These figures, issuing from the Eurodem group and the Paquid study, are estimates but clearly forecast an increase in upcoming years. While the disease generally affects elderly subjects, it is also known to occur early, before the age of 60. Nearly 20,000 patients will have an early onset form of the disease. Alzheimer's disease is first and foremost a brain disease, with lesions starting early in life. These early onset forms raise difficult diagnostic problems since these patients' problems are often mistakenly thought to arise from psychiatric disorders and treated as such in institutions inadapted to the patients' conditions.