system
Given the following post, respond as if you're commenting on Reddit:
human
Can an individual actually "fight to live" or "give up and die"?

I don't mean this via not eating, drinking, or something necessary like that. Is there a hard-nosed approach to the relation between one's psychophysical health and life?

eg. From Viktor Frankl's *Man's Search for Meaning*

"The prisoner who has lost faith in the future—his future— was doomed . . . I once had a dramatic demonstration of the close link between the loss of faith in the future and this dangerous giving up. F--, my senior block warden, a fairly well-known composer and librettist, confided in me one day: ‘I would like to tell you something, Doctor. I have had a strange dream. A voice told me that I could wish for something; that I should only say what I wanted to know, and all my questions would be answered. What do you think I asked? That I would like to know when the war would be over for me. You know what I mean, Doctor—--for me! I wanted to know when we, when our camp, would be liberated and our sufferings come to an end.’
‘And when did you have this dream?’ I asked.
‘In February, 1945,’ he answered. It was then the beginning of March.
‘What did your dream voice answer?’
Furtively he whispered to me, ‘March thirtieth.’
When F--—told me about his dream, he was still full of hope and convinced that the voice of his dream would be right. But as the promised day drew nearer, the war news which reached our camp made it appear very unlikely that we would be free on the promised date. On March twenty-ninth, F—suddenly became ill and ran a high temperature. On March thirtieth, the day his prophecy had told him that the war and suffering would be over for him, he became delirious and lost consciousness. On March thirty-first, he was dead. To all outward appearances, he had died of typhus."
gpt
Research seems to indicate that willpower or despair does not significantly affect mortality.

Hospital nurses (me included) can give you lots of anecdotal evidence. We like to tell stories about patients who, on being told they had a terminal illness, apparently "gave up" and died before the illness seemed severe enough to be fatal. However we also have stories of people who had great attitudes, were bound and determined to beat the illness, and died early anyway. So anecdotes, including the Frankl one you quoted, are not much help.

There is some correlation between depression and poor outcomes, but it may be that the depressed patients are those who are sicker to begin with. That is, more serious illness may cause depression, rather than the other way around.