In Michael R. Fletcher's dark fantasy novel Beyond Redemption (HARPER Voyager, 2015), a novel where belief and insanity shape reality, the Theocrat suffers from the Syndrome of Subjective Doubles. In Richard Ayoade's black comedy The Double the main character of Simon James is theorised to suffer from the Syndrome of Subjective Doubles with his doppelganger James Simon. William Peter Blatty’s novel Legion, a sequel to his novel The Exorcist, features a character named Dr. Vincent Amfortas who self-diagnoses his own case of Doppelganger Syndrome.