I would've just told him/her that money can help a lot but in the end, it can't force you to make you feel like living and life won't still make any sense with it.
As for me, I will be suicidal no matter how much money, love, friends and great times I have.
I find existence pointless. We're just apes stuck on a blue rock who get older and die and started existing in spite of never having asked for that.
Nonsense!