demons in a life

Life has been a difficult row to hoe the last few months. My 16 year old son's friend has been staying with us on and off because of problems at home. If this were the extent of it, I would be just fine. Adding one more teen to the mix in this house would be nothing to me. The issue is, it isn't just adding a teen whose home life stinks; this boy has some serious issues he brings with him. He is convinced that there is a demon telling him to kill himself. Apparently, the demon has now told him if he doesn't take his own life, the demon will kill 4 of his friends (my son being one of them). Now, I believe in the existence of demons. Jesus dealt with demons in the New Testament and I believe Satan uses his demons to attack Christians today. I also believe, though, that Jesus is more powerful than any demon we may encounter. Last night, as I tried to explain this to this young man (who is a child of God) my heart was breaking for his pain. He just isn't thinking straight and does not see any hope for his future. He has seen a Dr as recent as last week. The Dr held him in the hospital for a few hours on suicide watch and then released him...no medications. I was appalled at the level of his depression that he was not put on medicine. My son is overwhelmed at this point. He did not know how deep this was going to get when he got involved. He was crying last night as well saying he couldn;t take this anymore. I need to watch out for my own son but cannot turn my back on this young man either. I am riding an emotional roller coaster that is a living hell. I want to get off but the ride won't stop. I have prayed and prayed for deliverance for this young man but so far to no avail. One minute he seems happy and fine--the next minute he is ready to take his life. His moods are unpredictable and although he has always been honest and respectful with my husband and me, it is wearing me down. I have used all resources that I know of and so far have come up empty. This seems so unfair yet I know God has a plan. I continue to trust, even if that trust is weak right now.