Ethical considerations for the conduct of antidementia trials in Canada.

Clinical trials in persons with dementia bring into focus the ethical dilemmas frequently confronting the clinician-scientist. Despite the existence of various ethical guidelines, most with common underlying principles, few are specific to dementia. A particular difficulty is finding a balance between respect for the autonomy of the individual and the protection of vulnerable persons, while at the same time defining an acceptable risk/benefit ratio for the study. The availability of symptomatic treatments for Alzheimer's disease also now make it difficult to argue that withholding treatment from those in the placebo arm of a clinical trial fulfills one's duty to provide best care. Those conducting clinical trials must be knowledgeable about existing legislation and ethical guidelines in order to justify to themselves and others, the design of clinical trials and their risks. They must be prepared to educate patients and family members about dementia and research, determine each potential subject's competence to consent, and ensure that decisions about participation are in accordance with the best interests of the subject. Ethical conduct of clinical trials of new antidementia therapies will require that everyone involved understands the values and beliefs that guide their decision-making and the potentially conflicting roles facing the clinician-scientist.