I don't really think being on the meds would really make much of a difference honestly. Just like you have to write off a car after decades of Wisconsin winters slowly consuming the frame, he is much too far gone and really needs to be written off by society.
Nah, seen this many times, once his enablers pass away he will have no choice but to man up and get along with his life.
Strange but once the enablers disappear from someone's life their mind set changes and
gives the person a reason to fight for their lives, to survive and without enablers they become better, and stronger people.