My friend is driving me nuts! How can I help him?

One of my friends from high school is worrying me. He's always acted strangely and he tends to mooch off of people so I'm really the only friend he has left. He was having hallucinations and delusions about a year ago (it's a really long story) and his mother took him to a clinic where he was diagnosed with schizophrenia and put on meds. He starting improving and then stopped taking them. He's getting really bad again and his mom won't help him. She is his only living relative and as I am the only friend he has left he keeps coming to me for help, but there's nothing I can do. I'm getting to the point where I can't stand him but I feel bad about cutting off someone who is ill and has no one to help. He can't hold a job and has no source of income. His case worker put him on food stamps but in order to stay on them he needed to bring in some paperwork. He blew off the appointment because he didn't want to go. His case worker tried to set him up again wiht appointments for food CONT'D.