Serious research into such substances began in the early 1950s, during the Korean War, following reports of "brainwashing", a method of interrogation by Chinese and North Koreans of prisoners of war. The U.S. Air Force began a project to find the truth serum; U.S. pilots would be administered and trained to resist brainwashing.
The first experiments were with barbiturates, amphetamines, alcohol, and heroin, but most of the substances only helped subjects lie with greater skill.
The Trials of Stalinist Purges
The fear of mind manipulation techniques arose in the 1930s and 1940s as a result of the scandalous trials of Stalin's purges in the Soviet Union and socialist bloc countries.
The sodium pentothal, a barbiturate used by anesthetists to relax patients before surgery, is often called truth serum. Its purpose, in this context, is to help create a state of disorientation.
The subject is given a strong dose of the serum, which leaves him unconscious. Benzedrine is then injected as a stimulant to resuscitate the subject only partially. Already in a state of semi-consciousness, he is at the mercy of a psychiatrist, who with hypnotism techniques modifies his perception of what is happening around him.
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