My parents have enablde my brother in his disease all his adult life. They were always so afraid of all the "what ifs" that they never expected more of him. Each time he got in a pickle, they threw the net under him to get him out of it. He lived with them on and off most of his life, and has been there full time now for the last 10 years. My Mom comes up with all kinds of reasons for why she buys things, drives him around, etc. They walk on egg shells sometimes just so they don't upset him.
I know they love him, and they think that what they do is all about love. But he is now 51 years old....they are in their 80's. He is no closer to an independent life than the day he moved back in 10 yrs ago. How have they helped him in the end? What happens when they're gone? They don't have anything, so there will be no sudden windfall. As lovetohikect said...he has been allowed to rot under their roof. Whatever chance he had at a real life, had he been forced to deal with consequences, is pretty much gone. He is depressed, and hates his life. They have had no peace in their life.
Don't be my parents. Go to AlAnon, learn the tools and get the support to make truly healthy choices for you and your son.