Informed consent in demented patients: a question of hours

Dementia, and especially Alzheimer's disease is today the subject of endless research, most of it including some kind of prolonged physical treatment. When considering such treatment, one first has to deal with the quality and validity of the consent of the demented patient suspected of impaired judgment. The term 'informed consent' involves at least two types of decisions: one regarding short-term intervention like a surgical procedure; the other concerns long-term intervention, like treatment by a new kind of drug intended to improve memory. In the latter case, the informed consent attributed to the patient raises both clinical and legal questions regarding validity of the continuing authorization given to the physician--a question which should also be examined in terms of time in fluctuating conditions, like dementia. What are the tests required to determine competency? What determines the grade of competency required in different types of research with different benefit-risk ratios? Do the changes in the cognitive function of the patient during the research demand constant assessment of competency. Where is the 'cut-off' point that dictates reassessment of the patient's consent and who is legally and practically responsible to identify this condition and decide whether to proceed? Finally, what are the alternative procedures that might simplify the decision-making process in fluctuating conditions without affecting the rights and autonomy of the patient? This article proposes several possible solutions to these legal and ethical dilemmas.