No, you already got hints in TW2. In his conversation with Philipa, when he recalls his childhood - all his observations how people behaved, waiting for Philipa's approval, and all, which is something that he feels very strongly about, it is obvious that he became obsessively paranoid - constantly observing, analyzing, suspecting, always believing people were making fun of him, and so on. I felt that he was on his way to become this universe's Mad King. I wouldn't have bet that CDPR would go all out with this, but to portray him as very reasonable and logical - not a chance.