Bibliotherapy

I never heard of it before.

Seems like the kind of neologism that anyone could put together and which therefore might be hard to track. (I assume it means book therapy.)

Wikipedia says it dates to the 30's.

Samuel Crothers first used the term "bibliotherapy" in 1916. It was adopted
by librarians who saw the value of having a special designation for the
practice of selecting and using books helpful to psychiatric patients.

Here is a reference to that use:
"A Literary Clinic", The Atlantic Monthly, Vol.118, No.3, (September 1916),
pp.291-301