Two barbiturates have reputations for being “truth serums.” Even though these drugs have been used under certain conditions to interrogate people, the reliability of the information people give under the influence of these drugs is questionable at best.
Some drugs will produce states of semi-consciousness that can remove inhibitions, relax defenses, and make people more open to suggestion. Drugs that are reputed to be “truth serums” work in this manner.
Truth serums are labels given to numerous drugs with hypnotic or sedative properties that have been used to get people to tell the truth.
The rationale is that these drugs remove resistance and mental control to consciously attempt to fabricate or mislead when a person is questioned or interrogated. Two of the most widely reputed truth serum drugs are the barbiturates Amytal Sodium (amobarbital) and Sodium Pentothal (thiopental).
Barbiturates work by reducing the activity in the brain and spinal cord. These medications facilitate the release of gamma-Aminobutyric acid, abbreviated as GABA, which is the main inhibitory neurotransmitter in the brain.
When this neurotransmitter is released, it results in reduced neuron activity. This produces relaxation, sedation, and feelings of well-being or even euphoria.
Legitimate medical uses for barbiturates include the following:
Although the use of drugs to extract information from people predated the 1943 book Narco-Analysis: A New Technique in Short-Cut Psychotherapy: A Comparison with Other Methods, and Notes on the Barbiturates, this work described the clinical use of barbiturates and other drugs to get information from people.
The case studies describe hypnotic-like states that occur in people under the influence of narcotics and barbiturates that leave them speaking freely without anxiety or regard for what they were saying. It was this book and subsequent clinical descriptions of similar data that helped to popularize the notions of real serums.
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The use of drugs to extract the truth from individuals has not been upheld in the courts of the United States; however, it is occasionally used in forensic cases.
The FBI and other federal law enforcement agencies vehemently state they are opposed to the use of these methods to extract information from prisoners. The United Nations considers the use of any of these so-called truth serums to be a form of physical abuse.
Two barbiturates are often touted as truth serums.
Sodium Pentothal is a very short-acting barbiturate that induces sedation for only a few moments. It also decreases breathing rate, heart rate, and blood pressure, and it suppresses the activities of the central nervous system. It may be used as an anesthetic or an anticonvulsive medication. It has been used in the past as a truth serum.
Amobarbital or Amytal Sodium is an intermediate-acting barbiturate medication that can produce sedation for several hours. It acts in the same manner as Sodium Pentothal. It has also been used as a truth serum. When it is given in this manner, the resulting interview is often referred to as an “Amytal interview.” Other barbiturates could conceivably be used for narcoanalysis because they all have a similar mechanism of action and produce similar effects. However, these two barbiturates are the most notorious barbiturates that have been labeled as truth serums.
There is no consistent scientific evidence that suggests that either of the barbiturates mentioned above result in people telling the truth when they are under their influence.
Certainly, people become more talkative, less inhibited, and more open to suggestion, but the evidence indicates that these individuals are not always telling the truth. Very often, they can lie consciously.
When people drink alcohol, their inhibitions are lowered; they become very talkative; and they may reveal information they usually wouldn’t reveal. However, alcohol intoxication, which has similar effects to barbiturate use, does not result in forcing people to tell the truth if they do not want to.
The same is true with barbiturates. In fact, under heavy sedation, people under the influence of barbiturates often ramble and make very inconclusive statements as opposed to being truthful and unable to confabulate.Truth serums do not force people to tell the truth, and they are not serums.
LSD was used as a form of truth serum during the Cold War.
The bottom line is no drug, device (like a polygraph), or even form of torture that can guarantee that all the information extracted under its use is truthful.”
Barbiturates may make people more talkative and less inhibited, but they cannot force people to be truthful.
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(2005) Is Truth Serum Torture? American University International Law Review. from https://digitalcommons.wcl.american.edu/cgi/viewcontent.cgi?referer=https://www.google.com/&httpsredir=1&article=1140&context=auilr
(March 2013) Judge approves use of 'truth serum' on accused Aurora shooter James Holmes. The Guardian. from https://www.theguardian.com/world/2013/mar/12/judge-approves-truth-serum-james-holmes
(December 2015) Stranger Than Fiction: Is there any truth in truth serums? Science History Institute. from https://www.sciencehistory.org/distillations/stranger-than-fiction