Advance directives, substituted judgment, and the best-interest standard all have limitations that constrain their usefulness in making medical decisions for patients who cannot choose for themselves.
Because regulatory approval of cognitive enhancement drugs is likely, physicians may want to consider whether they would condone the practice for restoration of function only or for enhancement purposes as well.
Asymmetry in knowledge and power between (1) physicians and patients and (2) physician educators and their students creates a climate for possible abuse in both sets of relationships.
Advance directives do not always resolve questions about the best care for patients who no longer have decision-making capacity; physicians and patient surrogates can take alternative approaches to arrive at the best care decision.