A guy i know believes that he is not from earth, and is actually from another planet, does he need help?

At first people thought he was joking, but he insists that he is not of this earth, and that he visits his homeplanet every night that is on another galaxy, he believes his soul is not of his earth, he just looks human but isn't. Other than that the guy seems totally normal... he doesn't seem insane or anything. He just insists that his soul is of another galaxy.. Do you think he is not mentally well ?