Doubting the Bible specifically supports the perpetual virginity of Mary or goes against it. He is ultimately faithful to the tradition however and shows the Eastern fathers’ understanding of the perpetual virginity to be of equal weight to Protestant objection to it.
Now, back to the topic…
There is a mental disorder known as “trance and possession disorder”, at least in the WHO classification, in which a person periodically or episodically behaves as if he is possessed by a demon, ghost or the spirit of a dead person, but returns to normal in between. (This is very much a culture-based phenomenon; in the West, such persons would probably have “multiple personality disorder”). Many of these cases can be traced back to overwhelming anxiety or depression, adverse life events, or childhood adversity (abuse, neglect). So, yes, some cases of apparent “demonic possession” can be explained in purely psychological terms. However, this does not rule out the possibility of a true demonic possession, which both exorcists and some psychiatrists have been clear in pointing out.
