As indicated by Sara, one gets the feeling there is something unsaid in this question.
While besotted and adversely influenced by a spoiled girl, our son who previously was a source of pride for his honesty, good nature, achievements, etc. went hugely out of character and lost focus on his studies, was attracted to posing and living beyond his means and, worst of all, started lying to us. We made it clear we were not going to finance his lifestyle and his education costs would henceforth be reimbursed on successful exam results (no reimbursement if he failed). We have no regrets over this decision, but our relationsip with him (mine in particular) although amicable has never recovered to the the close friendship we had and he continues to lack proper connection to reality. He owes a ridiculous amount of money to the banks (nothing to show for it), the girl dropped him after draining his wallet, He failed to achieve his potential educationally but is in a fairly safe although financially poorly rewarding job. In short, he has let himself down much more than he has us but this was his choice from the age of 18 onwards and we feel it is not for us to "make" his life. Once we are dead that prop would abruptly disappear, and then what ? Ours was not a case of giving up, more like drawing the boundaries clearly and sticking to them.
I know of a woman now in her mid forties who became a drug addict as a teenager, progressing to heroin, whose parents "gave up" on her - and I can understand people trying to haul someone up for so long, but only so long. She then decided, all by herself, to reform herself. She went to her parents yet again for financial assistance and they provided it. She became "clean" and remains so to this day but it cost her 15 years of her life and quite a bit of permanent damage to her health too plus she has no recollection of any major world events of the period when she was "out of it"