Cholinesterase inhibitors and memantine can slow the course of Alzheimer's disease. In Austria the frequency of treatment is in the upper third among countries of the EU. Yet, the majority of Alzheimer patients does not receive adequate medication. Compliance to treatment is low. Studies on cholinesterase inhibitors show that only one third and one fifth of patients adhere to medication after 3 months and 12 months, respectively. Causes for low compliance are only partly patient-related, many factors are system-inherent. Knowledge of these factors is a pre-requisite for the treating physician to improve current unfavourable situation. Present treatment strategies are symptomatic, causal disease-modifying therapies are urgently needed. Research activity in the field is high and dominated by the amyloid hypothesis. We here review the basis and recent studies on secretase-inhibitors, immunization, aggregation of Abeta, statins and PPARgamma-agonists. Research towards strategies against tau-pathology is less dominant and focuses on inhibition of kinases and increase of activity of phosphatases. Causal therapies would have great effects on a population basis even if efficacy is only moderate. A disease-modifying therapy which delays the onset of Alzheimer disease by 5 years, will probably reduce the number of patients by nearly 50% during the next 50 years.