The Law on End of Life Care is now effective in Quebec. This law provides for a system of advanced medical directives. Respecting advanced directives (AD) issued in anticipation of incapacity can be a beneficial ethical way to ensure self-determination of the patient in a context where a person’s incapacity is total and of short duration (e.g., terminal cancer). But what about when the loss of decision-making abilities is gradual and spread over a long period of time, as is the case of people with Alzheimer’s type dementia (ATD)? Although the cognitive decline associated with ATD legitimizes the use of AD to promote self-determination of these people, relying solely on a person’s wishes expressed verbally or in writing to their relatives or physician to guide care is an approach that can be ethically risky. A review of the literature on AD, a study of the clinical features associated with ATD, and a critical analysis of a fictitious clinical case will help demonstrate the need for developing a gradual approach to revalidate agreements that take into consideration the AD of the person with a ATD while weighing their wishes and views in real time, their current quality of life and that of their caregiver. The beneficial deployment of AD relies on the ability of the actors involved to consider this as a process of revalidation of agreements. This necessary paradigm shift will ensure that actualising the self-determination of people with ATD does not come at the expense of their dignity, safety and integrity. Such an approach remains to be developed and promoted for people with ATD in Quebec. Health policies that move in this direction, as well as specific normative benchmarks for this clientele, are needed rapidly in the current Quebec context, which is joining the development of a system of “advanced medical directives” with a Law on End of Life Care.