Hello. I Believe My Brother Is Depressed And Needs A

Hello. I believe my brother is depressed and needs a psychiatric evaluation. He's lost his appetite, doesn't want to socialize with any of this friends, and says that people annoy him. He doesn't remember what happiness feels like. I have brought up my concerns with him about his mental health. He says that he can fix it on his own. I think he really needs to see someone but he refuses every time. What else can I do?