Periodically I have been asked for my clinical opinion on a potential neurological condition afflicting someone. It's not often, but I have been asked about such diverse things as stroke, Creutzfeldt–Jakob, and Parkinson's. While I might be able to give some insight, for example I did correctly recognize the beginning signs of Parkinson's in one person, I do not offer it for one very good reason: I am not a clinician. My advice is always to go see one.
But recently I received an email in which I was asked to help someone not as a clinician but as a scientist. The person in question has a publicly open blog and youtube channel so I don't think he would mind me posting this; if he does he is free to ask for its removal. The body of the email is essentially the same as the blog. I also want to make clear that my goal is not to make light of individuals who may or may not have a disease of the mind, but to bring attention to it.
This individual believes he is telepathic and is looking for a neuroscientist to study him. The problem is that the telepathy he claims to have sounds reminiscent of the hallucinatory symptoms of schizophrenia. He recognizes this but argues that it is possible that most patients diagnosed with schizophrenia are also in fact telepathic. (He also makes the contradictory claim that he believes he may be the only person in the world with telepathy). He claims that an individual is talking to him, telling him that he is a worthless person, causing him to smell things that aren't there, and control muscles both on his face and in his gut.
Now while he may in fact be telepathic, the vast body of research suggests that telepathy as a phenomenon does not exist. So my advise as a researcher would be to look at other explanations. He may be an individual who is suffering from mental disease. There is no more shame in that than there is shame in having a liver disease, no matter how society tends to treat such individuals. But I have not the expertise to diagnose that. So the advise I would offer him is the same I offered to the person who thought their mom had Parkinson's: seek the advice of a clinician.