Deep brain stimulation (DBS) as investigational intervention for symptomatic relief from Alzheimer disease (AD) has generated big expectations. Our aim is to discuss the ethical justification of this research agenda by examining the underlying research rationale as well as potential methodological pitfalls. The shortcomings we address are of high ethical importance because only scientifically valid research has the potential to be ethical. We performed a systematic search on MEDLINE and EMBASE. We included 166 publications about DBS for AD into the (...) analysis of research rationale, risks and ethical aspects. Fifty-eight patients were reported in peer-reviewed journals with very mixed results. A grey literature search revealed hints for 75 yet to be published, potentially enrolled patients. The results of our systematic review indicate methodological shortcomings in the literature that are both scientific and ethical in nature. According to our analysis, research with human subjects was performed before decisive preclinical research was published examining the specific research question at stake. We also raise the concern that conclusions on the potential safety and efficacy have been reported in the literature that seem premature given the design of the feasibility studies from which they were drawn. In addition, some publications report that DBS for AD was performed without written informed consent from some patients, but from surrogates only. Furthermore, registered ongoing trials plan to enroll severely demented patients. We provide reasons that this would violate Art. 28 of the Declaration of Helsinki, because DBS for AD involves more than minimal risks and burdens, and because its efficacy and safety are not yet empirically established to be likely. Based on our empirical analysis, we argue that clinical research on interventions of risk class III (Food and Drug Administration and European Medicines Agency) should not be exploratory but grounded on sound, preclinically tested, and disease-specific a posteriori hypotheses. This also applies to DBS for dementia as long as therapeutic benefits are uncertain, and especially when research subjects with cognitive deficits are involved, who may foreseeably progress to full incapacity to provide informed consent during the required follow-up period. (shrink)

Vulnerability has become a popular though controversial topic in bioethics, notably since 2000. As a result, a common body of knowledge has emerged distinguishing between different types of vulnerability, criticizing the categorization of populations as vulnerable, and questioning the practical implications. It is argued that two perspectives on vulnerability, i.e., the philosophical and political, pose challenges to contemporary bioethics discourse: they re-examine the significance of human agency, the primacy of the individual person, and the negativity of vulnerability. As a phenomenon (...) of globalization, vulnerability can only be properly addressed in a global bioethics that takes the social dimension of human existence seriously. (shrink)