When people are ready to, they change. They never do it before then, and sometimes they die before they get around to it. You can’t make them change if they don’t want to, just like when they do want to, you can’t stop them.

Andy Warhol (1928-1987) American artist, author

POPism: The Warhol Sixties, “1965” (1980) [with Pat Hackett]
    (Source)

Regarding drug and alcohol use.