Advance directives and personality-changing illness

An advance decision (AD) to refuse treatment allows an individual to express his/her wishes regarding future treatment in the event of losing capacity to make decisions. Relevant and applicable ADs are legally binding, even when refusal of the specfied treatment will lead to the patient's death; but health professionals are required under the Mental Capacity Act to consider a number of factors in deciding whether a patient's AD should be followed. The decision for the health professional is not always clear-cut. For example, what happens when Alzheimer's changes an indivdual's personality so much that they seem to be a different person: does their previous decision still stand? This article examines the criteria to be considered in such a case, and highlights the wider principles to be followed in making any decision on whether to follow an individual's instruction to refuse treatment.