Yes, it could lead to delusions. The sufferer would believe that they should be everywhere at once, and thus become deluded into thinking that they are really nowhere. I don't really think that a brisk walk would do any good, because there would be the belief that the walk is leading nowhere, and that the ubiquity feeling is really becoming an illusion. Hmmm. I must speak with my learned colleagues about this - if I can find them.