While it may sound horrible, the best thing you could do is concentrate on your helping your Grandson, who can't help himself and yourselves right now. There is really nothing you can do for your son, because only he can help himself. Sometimes the more you try and help, the worse things can become. I hope your son at some point will have an awakening. I assure you he knows what is going on. Pointing it out will only bring up strong walls of defensiveness. I hope for the 4yo especially that things improve.