Richard Gallagher is a board-certified psychiatrist and a professor 
of clinical psychiatry at New York Medical College. He is at work on 
a book about demonic possession in the United States.

https://www.washingtonpost.com/posteverything/wp/2016/07/01/as-a-psychiatrist-i-diagnose-mental-illness-and-sometimes-demonic-possession/


"People Who experience mood swings, fear, voices and visions"