What's interesting about this stuff is that it seems to support interpretation through multiple cognitive frameworks. There could be a mystical/esoteric explanation for why those people became so attached to the characters or fictions. Or it could be that they were already vulnerable to schizophrenic or depersonalization/derealization-type disorders.
It's like how you'll sometimes hear/read people say that tantra/mediation stuff like Kundalini can be dangerous because it results in an energy imbalance that could potentially be irreparable and/or lead to lasting damage.