experiments in this kind of thing started with the nazis and migrated to both sides of the Iron Curtain after ww2.
Some "mind control" techniques were said to have been used against american prisoners of war during the Korean war, which is where the Manchurian Candidate movie got the idea.
the US version was declassified eventually and there's a lot thats been published about it
https://en.wikipedia.org/wiki/MKUltra