Still on the issue of so-called schizophrenia, biblical counsellors must note the difference between the way in which Scripture understands such behaviour and the way in which the world understands it. Dr. Jay E. Adams has included a good section on this in The Christian Counselor's Manual.
While many are "diagnosed" as being "schizophrenic", often what is involved is something far less serious than the "diagnosis" suggests. In the mind of a person who simply believes the suggestions of the psychological and psychiatric world, "schizophrenia" is a very big and very serious condition. It looms above ordinary people who simply presume that because an "expert" in these things has made such a "diagnosis", it must truly be a deep, complicated and certain problem.
The jargon suggests that this is something that may be caused by a chemical imbalance. That sure sounds way too complex for a mere ordinary person to understand. This is a sad perception. Other "experts" may suggest it is caused by a genetic problem, a brainproblem, a glandular problem or even a hereditary problem. There are many suggestions as to why some people conduct themselves in a way that is commonly "diagnosed" as "schizophrenia".
Unfortunately, what is often given a big, complicated, vague name, is often simply the lifestyle a person has developed to camouflage his selfish, irresponsible behaviour, and to divert other people's attention away from the true nature of their behaviour. Consider David's actions in 1 Samuel 21:13. Behaviour often "diagnosed" "schizophrenic" is sometimes the result of unresolved guilt in that person's life, gnawing away at his heart and conscience until he deals with it in a biblical way (Proverbs 28:1).
It could be the result of a lifestyle this person has developed where they have practised unbiblical thinking and living (Proverbs 5:22, 23). In the unsaved, it could be the result of demon activity (Mark 5:1-16). It could be the result of God's judgement on personal pride (Daniel 4:1-35). It could be the result of drug abuse (Proverbs 23:29-35). It could very well be the result of jealousy, anger, resentment, by which a person's perception of reality is distorted, leading to pervading suspicion and fear (1 Samuel 18:6-10, 28-29). It could certainly be a lack of sleep (1 Kings 19). It could be the result of the ingestion of toxic substances, a tumour of the brain, a glandular malfunction, perceptual problem (referring to the person's ability to see or hear).
Excellent resources on this issue include Robert Smith MD, The Christian Counsellor's Medical Desk Reference, Edward Welch (PhD in Neurophysiology) Blame It on the Brain and also Counsellor's Guide to Brain Disorders. Here you will find the mature thought of qualified men who unmask and explain behaviour that for decades has been the subject of hopeless thought. God has solutions even for those "diagnosed schizophrenic"!