C.S. Lewis on reality (paraphrased): "Everything is real. The question is, are they real snakes or real delerium tremons?"
Or as they say down home, "The silly boy picked up a snake to kill a stick."
Schrader is just like most of the rest of us - he sees what he is, but in his case reality is illusion and illusion is reality.
Exactly, logos. Voegelin makes much the same point. Wish I could quote him here (it's a very amusing insight), but the source is at home.
The jist of what he said is that even the visions of a psychopath are real enough, in that they enter into empirical reality.
But to the extent that they are "deformations of reality," and thus deformations of the truth of reality, they enter into the world as sources of disorder: What starts out as personal disorder finally, ineluctibly translates as a source of social disorder.
I think this may be the case with Schrader. As you note (fairly I think), "in his case reality is illusion and illusion is reality."