[Research on humans suffering from dementia].

The urgent necessity for dementia research is justified by the prevalence and increase in dementia associated with the demographic changes, for which no causal treatment is available; however, during the progressive course dementia destroys the capacity for self-determination of persons affected and thereby an essential prerequisite for participation in research, i.e. a valid consent to a research intervention. Accordingly, not only sufficient information about all issues which are relevant for decision making by potential participants but also a flawless assessment of the capacity to consent are important; however, currently this is not satisfactorily possible. This article attempts to answer questions associated with these problems, such as how consent can be established, including that of a surrogate for consent of potential research participants by whom consent is no longer possible. In a second section the benefit-risk evaluation, which is also underdeveloped, will be dealt with using two concrete research examples, a diagnostic and a therapeutic research intervention for patients with dementia.