Hey there, I came across this in the British Psychological Society's magazine which looked like a tasty read: 'The Heartland: Finding and Losing Schizophrenia' by Nathan Filer.
Not sure how good it is, as I haven't read it, but definitely takes a critical look at the diagnosis and the place of Schizophrenia in the history of psychiatry. Alternatively, Mind often have empowering rather than solely medicalised info on their website for survivors: https://www.mind.org.uk/information-support/your-stories/schizoaffective-disorder-and-me/#.XUQQ3C2ZM1I