What Does Difficulty In Maintaining A Person To Person Conversation Indicate?

A friend seems to be suffering from some mental issues. He thinks he can read other people s minds and they can read his. He cannot maintain eye contact because this may make the problem worse. He has difficulty, in fact it s near impossible, to maintain a person-to-person conversation because other dialogue is going on at the same time. He hasn t said it in so many words, but there seems to be only one voice at a time, rotating through images from television, eye contact and whatever stimuli he encounters. He has a doctor s appointment in two weeks and he s submitted a blood test to his doc. I am asking because I don t know and I m concerned.