Creative work requires huge efforts in such a personal sacrifice and dedication as exceptional among ordinary mortals, that there could be the source of serious personal consequences.
According to psychoanalysis, literature is an organized form of delirium, said Freud: "The instincts dissatisfied are the driving forces of fantasies, and every fantasy is a wish dissatisfaction, a rectification of unsatisfactory reality ". As if being mad was to be a writer or vice versa.
Art and madness touch, that's for sure, but the differences between madness and art are evident. Writing can transform insanity into an a fact, it's not just a download of words, it is structured language that communicates something.
Fears, nightmares, paranoia, are ghosts that feed the writing, and the author reflects them in his works, voluntarily or involuntarily.
Other writers are really crazy, paranoid or schizophrenic as Strindberg or Artaud. You may be crazy, drunk, drugged, but writting needs a great lucidity and a huge control over what you are doing...
An artist goes in sane and lucid into his personal hell and comes back torn and with arms full of valuable fragments of his guts, then builds something beautiful for others. The essential difference is the round trip, to sumurge your self in the underground hell and come back up, although there are no guarantees of it, and there are some get caught in the shadows.
I acknowledge that the writer's craft has side effects. I suffer social isolation, I get obsessed with my stories, live other lives, those of my characters, writing I lose track of time, I forget the world, but also fully enjoy what I do. Write protects me from other worst follies, teaches me, I humanizes, and that's not so bad...