Thousands of cases of "possession" occur around the world every year. The Catholic Church even has a team of Exorcists--whether they deny it or not. Do you think possession is real? And if so, do you believe that a human being has the power to exorcise the spirit?
No, and of course, my next answer would have to no as well. There are too many symptoms of possession that are also symptoms of mental disorder. Too many times, those with no education in either, jump to the conclusion that it is a possession.
Demonic possesion?? ...mmmmm not so sure. People suffer from paranoia, schizophreniaetc ...this can lead to, what seems like demonic possesion? ...but what triggers these conditions? we can kind of see whats happening inside ...but do we understand why? ....are the demons, rather than 'roaming around' looking to possess us, already inside us, and if we give them a chance make our thought process bad, i mean we are all, regardless of religion, nature etc,...made up of good and bad, negative and positive, so it figures if we allow one side dominance (the bad side) it will manifest as demonic possession? hey sorry if this is coming over as the ramblings of a madman!! i'm just typing as i'm thinking!! ;o)