A. Bummer! I really like "the blues guy." lol
B. Demons vs. schizophrenia is squishing something into too small a package. There really are demons. They really are active. It's not just schizophrenics they're active in and it's not always the cause for the schizophrenia. You're stuck back in 19th century thinking.
Let's bring it up to the 21st century. What do you think of the epidemic of ADHD sweeping the country? Is that demonic? Did something just happen where some cause made all those people suddenly not like your average person? What changed?
Two things changed for that:
1. "Discipline" became a naughty word.
2. Diagnosing became more accurate.
Hubby has ADHD. He's had it all his life, but he was disciplined as a child, (in such a horrible way there is a good chance that caused it. He really did have such a bad life growing up, he makes Sybil look like she grew up in paradise.) But schools did teach him methods that helped him learn how to focus too, and as an adult he could focus well enough that he learned new methods that work for him and some that don't. And he also learned when he needed to control it and when he didn't. (Not good to go off on a tangent in church. Fine in Bible study alone. He would spend four hours a night studying God's word, because he got hooked on one word, started learning about that word, but another word came up, so he went off on that word. After a full night of studying he learned five different words, but never got back to what he was studying. So next night he started where he left off and do the same thing. Good way to learn the Word if you're ADHD. lol)
But parents don't discipline their kids now, so they don't learn to control themselves and so many more ADHD's develop.
BUT in like kind, when hubby was young there was no ADHD. Well, of course there was, it's just no one thought about it enough to think it was really something. Back then it was always, "discipline your child better." A horrible feeling to want to learn but can't concentrate that well.
Likewise schizophrenia is both a real thing -- a physiological disorder of the brain that causes synapses to fire off that shouldn't or demons taking over the brain. If the medical community wouldn't dismiss the latter, it would be easy to diagnose the difference.
That makes it hard to tell. But it's not just them. Hubby's first wife was both bipolar and possessed. She was a new believer, and in the beginning of the Jesus Movement, so she was also one of the first to be delivered of demons for quite some time in that little church. (Poor AG church. They had no idea what they were getting themselves into. lol) Hubby saw it happen. Somewhere between empathy and disgust filled him, as he saw what happened to her when she was delivered, but she was delivered. AND she still had bipolar going on. (Back then it was called maniac-depressive disorder.)
And, she believed in God, but had this self-centered streak that won out, leaving the demons a place to call home again, so they were Legend. And then she tried killing him -- often. He's huge. She's petite, so he could get the knife out of her hands when she charged, but it's not like seeing someone running at you with a knife and seeing the look in her eyes to know the intent doesn't scare him. It was the morning when he woke up with her leaning over him with a razor blade (single edge like was put into razors in the 60's) necklace twirling in her hand, and she said, "Isn't it good I didn't slit your throat when you were asleep" with a smile that made him ask her to get delivered again. She wouldn't, so he was the one telling the orderlies she would try to kill them too or kill herself.
They saw a quiet, happy little woman in their wheelchair. He pulled that necklace hidden under her blouse off and then forced her hand open spilling the pills in it. THEN they took him seriously.
That wasn't schizophrenia. It's not always mental illness, but the two go hand in hand. It looks like it's mental illness. And then sometimes it is mental illness minus demons.
To me it's kind of like knowing that 10% of people with chronic depression (the type that has no cause, yet is still felt), are curable if they'd take vitamin B12 every day. That cures about 10% of people with chronic depression. In like kind, it isn't always demons causing psychological problems in people, but it does no harm to find out if that's the person that is demonically possessed.
I wonder if some don't have the ability to discern all the time. I can, some of the time. So can hubby.