Reply #21: Alzheimerss is a very slow progressing disability

[Marnie]

but physicians who deal with older patients are likely to notice symptoms and test for it a the same time they are testing for other types of mental and physical deterioration affecting the elderly. There was then and as far as I know still is no definitive diagnoses except by postmortem biopsy of the brain tissue.

But hindsight tells us that a person who is other wise physically healthy can survive physically for a decade or more after significant signs of mental deterioration are overtly noticeable

So yes, the WH knew Reagan probably had Alzheimer's and chose to let a man who was increasingly mentally incompetent keep his finger on the proverbial nuclear red button.
They endangered the safety of America and Americans at home and abroad in their own selfish need to stay in their positions of power.