This is a question that I think we are also starting to discuss at our panel at CAMH. I don't think we have clear, specific recommendations at this point. The complexity of the issue is that the capacity changes, and that's why the advance directives are important. When individuals may wish to have PAD at that time they may not have the capacity to execute it. However, the wish itself also could change.
From a clinical perspective, again, while dementia has probably a more predictable degenerative course in terms of the natural history compared to what I presented, it's also hard to predict the mental state the individual would experience. When they are incapable of making these decisions is not black or white.
I've seen individuals in the late stage of dementia who are quite content just to sit in a chair and smile. In some sense the neurodegeneration didn't result in severe anxiety or pain and they are dependent in their functions, but they seem to be content versus other individuals who have a different course and exhibit severe suffering at the later stage of the illness.
I'm sharing the complexities of the issue rather than sharing a specific recommendation. The wish may change the mental state of the individual even though they may be lacking in capacity, but the suffering itself may be different between one individual who is capable and projecting and imagining what it would be like for them when they are in that advance stage based on what they know of other individuals versus what could happen 10 years down the road from when the diagnosis was made.