In “On Avoiding Deep Dementia,” Norman Cantor astutely notes that, for some individuals, the concept of “protracted maintenance during progressive cognitive dysfunction and helplessness is an intolerably degrading prospect.” This cannot be argued with. Cantor's solution, however—that in the wake of a dementia diagnosis, patients should have the option to direct, in advance, instructions for voluntary stopping of eating and drinking should they develop a state of deep dementia—is more ethically challenging than it may first appear.
Respect for autonomy is one of the most fundamental principles of bioethics, and it requires that we allow patients with capacity to refuse life‐sustaining treatment, even when that treatment is something as seemingly innocuous as nutrition and hydration. If a capacitated person uses an advance directive to prospectively refuse artificial nutrition or hydration, then that treatment must be withheld if the person develops dementia and loses the ability or willingness to eat. Cantor is incorrect, however, in suggesting that an advance directive can require that nutrition and hydration be withheld from a patient with dementia who actively requests to eat or drink. Regardless of the language in an advance directive, caregivers cannot be compelled to abandon their duty to attend to the person's human dignity, nor can physicians be compelled to sedate a person with moderate or severe dementia because that person continues to be receptive to eating and drinking.