Hearing voices! What do I do?

My best friend, who is a former drug addict that suffered a relapse about a month ago, and is also type 1 Bipolar, is hearing voices every time he trying to go to sleep. He says, "Idk what to say. But make it stop. The f****** voices. The f****** screams. The whispers. It won't stop. Every time doze off. I hear people talking. Then it goes down to people whispering. Then a complete silence. Then a piercing scream wakes me up." When I asked him if he had a headache or had taken anything he said no. When I asked him if he could understand what they were saying he said, "I can't understand them. It's right as i fall asleep. It sounds like a hundred people at once all saying different things." When asked if he is depressed or stressed or anything, his reply is he doesn't know what he is. He wont go to a doctor because he doesn't want to be looked in the eye and told he is a psychopath. I don't know what to do or what to tell him. Please help me! I am worried something might happen to him.