0
You should read Valis, Philip K. Dick's thinly-veiled account of his own insanity. He alternatively thought his mind was being read by The CIA, The KGB, Space Aliens and God, all minifest as a beam of light that would hit him in the face.
Great novel. After that if you're further interested, start plowing through In Pursuit of Valis: Selections from the Exegesis, published ramblings from scores of handwritten notebooks containing Dick's various thoughts about philosophy and elaborate conspiracy theories. Dense and wild, but a good read.
__________________
"Film is a disease. When it infects your bloodstream it takes over as the number one hormone. It bosses the enzymes, directs the pineal gland, plays Iago to your psyche. As with heroin, the antidote to Film is more Film." - Frank Capra