Project MKUltra was an illegal human experiments program designed and undertaken by the U.S. Central Intelligence Agency (CIA) to develop procedures and identify drugs that could be used during interrogations to weaken people and force confessions through brainwashing and psychological torture.
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The project studied the effects of psychoactive drugs, particularly LSD, psilocybin, mescaline, cocaine, AMT and DMT on people
https://en.wikipedia.org/wiki/MKUltra