Arthur, I addressed all these questions about why drugs alter thoughts and behavior. Go back and read them. Cocaine can help people to cope by altering the brain and giving the subject a false sense of reality so that they function in a "normal" state. A person can have a brain tumor and experience severe headaches that lead to the inability to think or function. You can give them pain medications to function "normally", but have done nothing about the tumor. Understand?
You haven't addressed how someone can lose all sense of reality via a condition you deem can't be a mental one. Schizophrenia isn't the same as having an actual injury caused to the brain itself that brings it about. LSD brings about a hallucinatory state but it's not an illness obviously. Schizophrenia isn't something that lasts for 12 hours and then goes away. It isn't caused by a 'food allergy' or having a certain point of view. It's a serious medical condition that is treated with medication.
If you deny anti psychotic drugs to those afflicted then just what other measures are you going to employ - considering that in many cases there's no way to actually get through to someone in such an ungrounded state? Have you ever spoken to someone who is so out of touch with their actual surroundings? You could ask them for the time and get 'pineapple' as an answer...
If the medication helps with the primary problem then that's the objective and in some cases afflictions are simply set for life be they mental or physical, so the best one can do is to utilize the best help for such available.