The term therapeutic misconception was coined by Paul Appelbaum and his colleagues to describe the tendency of patients enrolled in clinical trials to confuse research participation with the personal clinical attention characteristic of medical care. It has not been recognized that an analogous therapeutic misconception pervades ethical thinking about clinical research with patient-subjects. Investigators and bioethicists often judge the ethics of clinical research based on ethical standards appropriate to the physician-patient relationship in therapeutic medicine. This ethical approach to clinical research (...) constitutes a misconception because it fails to appreciate the ethically significant differences between clinical research and clinical care.In this article I argue that the assumption that the ethical principles governing the practice of therapeutic medicine should also apply to clinical research with patient- subjects produces incoherence in research ethics and erroneous guidance concerning certain controversial research designs. (shrink)