I know of two cases in my own family where one elderly spouse died, and the other announced that they did not want to go on, and they died within about a week.
I definitely think there's a correlation between your mental and physical health, but it's definitely not a simple one.
It's pretty simple, actually. The body cannot live (thrive) without the mind.
These bonds root deep in us.
- tako tsubo syndrom, emotional shock => hormone cascade => myocard deformation to the point of uselesness
- arteries constrictions, nearly all your arteries (even micro capillaries) have tiny valve-rings, since fear can induce vasoconstriction to ensure high blood supply, I think high anxiety can force your system in that state for prolonged amount of time which will lead to blood flow disruption (tiny clots, mild hypoxia) and derail organs on the way.