Troubled by Faith: Insanity and the Supernatural in the Age of the Asylum, by Owen Davies

From the publisher's website: The early nineteenth century witnessed the birth of psychiatry, a new medical science that fundamentally changed how mental illness was labelled and understood. Troubled by Faith explores how psychiatrists not only thought they were agents of modernity but that they could also explain the occult mysteries of the past. They bristled with confidence that, in an era of unprecedented change, unlocking the secrets of the mind was essential to an ordered and progressive society. And a progressive society was one that did not believe in witches, ghosts, and fairies, and did not exhibit excited religious emotions and divine communications. 

Further information at the publisher's website: Oxford University Press.