I had seen this talk a while ago, Eleanor Longden. She seems to me quite a remarkable example of what, 'exceptional help,' can do for a person in circumstances such as you describe
Then there's Sapolsky's lecture on the topic; which by now, is a bit dated, and even back then, was probably still quite behind. Though he comes at it from neurological angle.
Then there is the old story of the man in the straight jacket, and the yogi. The yogi, an ascetic, and mystic, is hanging upside down from a tree branch, deep in meditation. A man comes up to him and asks, "why do they call you, 'Yogi,' 'Mystic,' and revere you; while me, they call crazy, lock me up, and restrain me?"
The yogi peeps one eye open, looks at him a bit queer and says, "The Yogi knows who not to talk to."
I have found, in my experience, there isn't really much difference between a crazy person (to put it one way) and a person who supposedly isn't crazy.
Some people will tell you, with every fiber of their being they see ghosts, or talk to ghosts, or have encountered ghosts. Psychiatry, as a an institution, claiming to be scientific, could only rightly conclude these are hallucinations. Yet, many people who believe in ghosts, or have encountered them, are highly successful and well adjusted people, who go about normal lives, and have never been diagnosed with anything.
Then we have people who claim to be, or with every fiber in their being, know, that they are psychic. Psychics generally are credited with having high intuition, the ability to read people, the ability to know the future, the ability to talk to the dead, the ability to communicate with ghosts, or perhaps communicate with aliens. Yet, again, pschiatry, would be apt to conclude in many cases, that these are delusions of grandeur, hallucinations, and so forth. Again, these people, who believe they possess extraordinary abilities, and the people who believe in their abilities, again, often lead very normal lives, are well adjusted, and perhaps even wildly successful, having written books, or raised families, or amassed small fortunes, or all three of those things.
Then you have people who believe they have encountered aliens, or seen demons, or seen angels, and all manner of wild sorts of things. Again, these are things many a psychiatrist would conclude are, 'hallucinations,' or, 'delusions,' or both. Yet again, many people, of all different walks of life, will tell you with every fiber of their being, they have encountered aliens, demons, or angels, or whatever; and they hold jobs, raise children, and are generally well adjusted, having never been diagnosed with anything.
Even as far back as the time, age, and place of Socrates, we have the story of when Socrates went to visit, 'The Oracle.' (I think it was the Oracle at Delphi? Not sure) So we know, as far back as written history goes, and farther back than that, there have always been, 'mystical people.' These mystical people were known as, 'Shamans,' 'Witches (in the pagan traditions),' yogis, ascetics, etc., etc.. There have always been people with a certain sort of 'genius level of intuition, insight, or clarity on things, 'strange and other wordlyl'.' And these people, generally, provided counsel to, 'regular,' people, on whatever it was they were seeking counsel for. Or they were a bit monastic, and only really had any connection with society, so far as anyone from that society was willing to seek them out.
So the above is interesting to consider. Imagine some one with a very high intelligence, if you will, but, who was never taught how to cultivate that natural skill. There are many people like this. They are low achievers, with low status, and all sorts of problems, despite the fact they are highly intelligent. They had no one to pass down, 'the tradition,' of how to navigate the world, with the innate skill-set they were given. So their greatest asset, becomes like a curse to them, because they weren't taught the knowledge on how to use their skill, to skillful ends.
So the above, can be the the bad news, I think. The good news, is that, it tells us, what separates a particular, 'us,' from, 'them,' really has very little to do with, 'hallucinations,' or, 'delusions,' or whatever; that it has more to do with, how particularly well adjusted a person is to themselves and their environment; how they respond to strange experiences; how they respond to intense experiences.
For example, let's say we have a psychic that can communicate with the dead. She does that for a living. And one day, while grocery shopping, she hears a malevolent voice. This is probably not a new experience to her. She probably knows, 'okay,' there might be some one near me, who has had some one in their life die recently, who had some unfinished business. So, she might cut her trip short, or go home and perform a certain ritual, or do this, or that, etc., to deal with situation/experience. She has a protocol, that she knows to follow. Perhaps she learned how to deal with these things on her own, after some trial and error, or perhaps she had some one teach her, early on. Either way, she is prepared for these things, for the most part.
So, it's about awareness, and knowledge. Intense experiences, can be difficult to navigate unfortunately; but, the awareness and knowledge is, what I would hope, allow us to navigate, and learn to skillfully live with ourselves.
Psychiatric drugs are just drugs. They can be useful, not useful, or harmful. I think the main problem is that, not a lot of people understand their profession very well, or the people they are treating, or the drugs they are prescribing. And on top of that, society not only does not have the time, but is unwilling to take the time, to truly, 'help,' people. There's too much busy work and profit to be made. It just isn't profitable to, 'help,' people, usually. And on top of that, it takes some one of keen understanding, and ability, who is in a position to actually help some one, to really do that sort of job. And it also takes some one who is receptive, and in a position to receive that help too.
So, it's always a sort of, 'timing,' sort of thing, with these sorts of situations. Where, all the conditions have to be just right; and the timing has to be just right.
Then we have the works and legacies of people such as: R. D. Laing, and Thomas Szasz, who were quite detailed and intimately involved with people who experience, 'intense experiences,' or, 'odd experiences,' to put it one way.
As for me, I think the mind is quite profound, and quite powerful. A voice in one's head, is ultimately, a voice in one's head.
One's head is their head. So that voice, to me, is part of that person. If my arm was numb, and I felt my arm, not knowing it was numb, it may feel like some one else's arm. Again, if my toe was numb, for example, it may not feel like, 'my,' toe, at that moment; but, if I can see that it is connected to me, then I know, it must be my toe; though, I may have to alter my behavior a bit, to protect it, being that I wouldn't be able to feel any pain if it was numb.
So there are ways to approach and try to understand circumstances like these, I suppose. A knowing is half the battle, sort of thing.
Some one else may have a different interpretation, however, of what a malevolent voice may be, to them; and their interpretation may be more helpful for them than mine, or some one else's; or vice versa...
As for me, I think that, generally speaking, in this mad world, anyone who isn't a certifiable nut... is only deluding themselves...
Or maybe put another way: we are all apt to hold and to have experiences, views, perceptions, beliefs and the like, that are quite mad, unbelievable, and not grounded in reality; and that there are no crazy people in the world, it's just that the world and the things it can confront us with, are often quite insane and unbelievable, whether those things are real or imagined.