The need for an early diagnosis of Alzheimer's disease (AD) is obvious. Approximately half of all individuals over the age of 85 years develop AD,^[1] and the risk of developing AD dramatically increases with aging, rising from 2.8% between 65 and 69 years of age, to approximately 23.9% between 85 and 89 years of age. Due to the longevity of the population in Western countries, the rate of affected people will evolve even more dramatically in the future. In Germany, more than 33% of the population will be older than 60 years in 2050 (press release 6th June 2003 of the German Federal Statistical Office). Thus, in Germany, approximately 1.2 million people suffer from dementia today, with a prognosis of 2.5 million persons in 2030, causing physical and psychological strain for patients and relatives. AD not only leads to disastrous consequences for the patients in regard to the quality of life and health, but also causes immense expense for society and for the healthcare system, for example, due to permanent disability. In general, the annual overall costs for dementia patients in Germany totals over €43 billion per year.^[2] In reality, costs are even higher, as a clear predictive diagnostic for AD and other dementias is unavailable. As a consequence of this suboptimal disease signature, patients are often not medicated specifically, but treated for a broader indication. This may lead to an inefficient and cost-intensive treatment...