Obviously I don't know the whole story here, but just from what you state about him taking mushrooms, he is definitely in a bad way right now. Have you gone looking for him? He needs to know that the support of his family is there, to help him, with whatever he is going through. And, what do you suppose caused him to become the way he currently is? And again, this just being my opinion and not knowing really what is going on...wouldn't an option be for you to let the police know about him, and have them take him in. Maybe that will help him see the reality of his life..and how much worse it may become. Or maybe send him into rehab? He is just to young for you to give up on him yet. This is so sad.