Yes Terril, mental illness is not a new phenomenon, it existed long before the Bible was written.I believe belief in ghosts, demons entities are the most widespread religious beliefs.
The new testament is full of stories of excorcisms, Christians still perform them,
my father a priest was an excorcist. Most christians would never have heard of OT 3.
Now we have a better understanding of it, but it doesn't stop conmen from cashing in on it