But even the brain can get ill and the evidence of such illness can be called paranoid schizophrenia. But there are other serious brain illnesses that can be mistaken as demonic possession by those not educated.
A psychiatrist friend (brilliant guy) was asked if some people who are diagnosed with mental illness might actually be possessed. He replied,”Yes, and I can tell the difference.”
Of course, he is employed by the hospital not a ministry so he doesn’t practice exorcisms ;).