Cro, this isn't really a story. It's more an example from personal experience.
When in college I was at one point studying to become a psychologist and for awhile I worked as a psychologist treating mostly schizophrenic patients. I had some patients that I would go to see, where they lived, not have them come to me like the other psychologists and counselors and doctors.
Because I had a theory that being with them where they lived would give me a completely different view of them, and them of me, than having them come to a stupid office. Which was sterile and impersonal and not very likely to trigger anything relational to their real experience of their various disorders.
So I'd go talk to them where they lived, view their drawings, saw what they ate, watched on television, listened to, what they read, what their rooms were like, etc. I'd go out in the yard and some of them would draw figures or maps in the earth or in the dust. Some would show me their drawings, and some would talk to me about their "images" and the things they saw on the walls and their hallucinations and visions, etc.
One guy would stand at the mirror in a hallway in the morning after he had eaten, showered, shaved, and dressed and describe to me the things he saw in the mirror (hallucinations and internal mental and psychological images) and tell me of the "voices" he heard, etc. He'd sketch them sometimes or sometimes I would, like a police artist, as he described them to me, and if wrong he'd correct me, and so forth til we had an actual image of his visions or hallucinations. I'd also often either record (on tape recorder) or write down in hand what he heard (as far as the voices in his head). Both the content of the images (which I sometimes called hallucinatory iconography, depending on the subject matter) and the verbal content struck me as equally important. Oddly enough this type of material didn't seem to interest most of my colleagues, except in the most abstract way (the way they would attempt to self-analyze it), but I considered it fundamental and seminal to the actual expression of the disorders. I had a theory that if you could unlock why these images and content expressed in the way it did, and what these things actually involved, you might be able to work back to figure out better treatment regimes, maybe even cures. I saw that work once as a matter of fact, but most of the psychologists working around me just seemed to want to heavily drug most of the patients, and for some of the more violent ones that was probably good procedure. Pragmatically speaking. But unfortunately drugs were the treatment form du jour no matter the actual details of the case, or more accurately, the simplistic way of avoiding making a real effort at treatment. And since it was subsidized at state expense, easy to justify to boot. But maybe that's neither here nor there to your interests. Nevertheless it's why I abandoned psychology as a profession. I saw enough do-nothing to convince me that if do-nothing was the order of the day, then I could do that all by myself at some other venture. I didn't need state help for that kinda thing. By the way I'm in no way condemning all those who work in the psychological/psychiatric industry. Many work awful hard to have some good effect. I'm just saying that from personal experience I don't have much respect for the way the industry tends to operate. Generally speaking.
Now you have to also remember I was working with people who had been officially diagnosed (rightly or wrongly, as there was often a lot of organizational and official misdiagnosis) with very specific disorders, the vast majority of which were classified as paranoid schizophrenic with vivid hallucinations, sometimes schizoaffective disorders of one kind or another, and occasionally dangerous psychopaths or sociopaths, or schizophrenics with known and recurrent violent impulses which they regularly acted upon (institutionalized). So in that sense my situation was limited to those specific forms of insanity. Later on after undertaking detective work I came to study criminal and violent criminal behavior, but I reckon this isn't what you're really interested in. I'm just saying my experience is sorta specialized in that respect.
So my experiences may or may not reflect at all what you are covering in this set of stories you are describing. I don't know your exact intent, or what you are hoping to uncover.
I'd say that some authors, like Poe, having their own set of mental subnormalities (abnormality originally didn't mean what it does today, a sub-normal functioning, but rather a functioning outside the norm which would have been described by the Greeks as monstrous, or well beyond normal, but not sub-normal, so I don't use the term abnormal to describe subnormal function) and abnormalities might write very well on things like madness and insanity. Others, like me, having had first-hand experience of the madness of others, and for one other reason, might well understand the surrounding conditional states and how those things actually operate in practice. Still other authors might have good imaginations and try to imagine insanity, with some getting somewhat close in their descriptions, and others being well off the mark.
I rarely write stories about insanity (except maybe criminal insanity), though I did write a long poem once almost directly after inducing in myself an acute set of hallucinations as an experiment to try and see what my patients were experiencing (to some degree). The experiment got out of hand, lasted far longer than I expected, had a number of temporary side effects, and scared the hell out of me (I never attempted to repeat the experiment) but it did give me some idea of what my patients were going through, induced psychosomatic reactions close enough to their experiences to assure me I had no real interest in extended bouts of insanity, and yet made me glad I understood their situations better.
(One thing I'd definitely say in this respect is don't forget the enormous physical changes that almost always accompany psychological and even some forms of mental and personality insanity. Many not familiar with real insanity think it is a mental change or disorder. the physical changes and disorders are almost always as easily evident and apparent as the mental disorders when encountering true insanity. The mind and soul cannot change without leaving deep impressions upon the body. I've never seen a severe case of mental or psychological illness that did not create a severe or at least strange change in physical appearance, habits, and conduct. Many often ignore the physical changes but to me it is a clue as to how exactly the disorder is actually expressing itself, and why .)
It seems to me though that I can almost always tell the difference between any writings in which the author has had their own real experiences with madness (to one degree or another) and those writings which are an evocation of mere imagination. It's like the difference between a guy who occasionally plays little league baseball and those who do it professionally in the big leagues for a living. It's a whole different kinda ball game.
Anywho, good luck to you and whatever it is that you're trying to do exactly.