According to the legend recounted by Beedle the Bard in The Tale of the Three Brothers, Cadmus Peverell used the Resurrection Stone to attempt to bring back a girl he had loved and was prepared to marry before her untimely death.
He was able to bring back a shade of her, he felt as though a "veil" separated them, and he could tell that she was suffering greatly from being forced back among the world of the living.
This seems to tell us that whoever is brought back by the stone is a real being, able of suffering.
Yet, in The Deathly Hallows, the "spirits" brought forth when Harry uses the Stone are clearly stated to be basically creatures of Harry's own mind/soul, not "resurrected" beings independent of him.
if that would have been the same effect for Cadmus Peverell, he would certainly not have had a "suffering" ghost presence who forced him to kill himself.
How does that square?