How Intelligence Agencies Came to Use Barbiturates as ‘Truth Serums’

Certain drugs work by exploiting the nether regions of human consciousness. The sedative-hypnotic Ambien, for example, induces an unnatural state between wakefulness and sleep. So-called “truth serums” are used with much the same intention: putting someone in a state of semiconsciousness, with the idea that the person does not have the mental focus to lie. In theory, it sounds like the stuff of science fiction and spy thrillers. In practice, the reality is quite different.

Continue reading to learn about how barbiturates work and how they have been used to try and discern the truth in various situations.

Barbiturates and How They Work

The term truth serum is a popular name for drugs more properly known as barbiturates, substances that target the central nervous system. Legitimate and trusted medical reasons for prescribing barbiturates entail:

  • Reducing anxiety.
  • Numbing pain.
  • Causing drowsiness, as a sleep aid.
  • Causing unconsciousness (as anesthesia before surgery).1

Barbiturates fall into three general categories, each roughly corresponding to how long it takes for the effects to wear off. A barbiturate like sodium thiopental (better known as Sodium Pentothal) kicks in roughly 20 minutes after it is administered, making it very useful for anesthesiologists who are preparing patients for surgery.

Another example of a barbiturate is phenobarbital, or Nembutal, which is used by veterinarians to euthanize animals.2

Twilight Sleep

Of all the different types of barbiturates out there, it was Sodium Pentothal’s ability to influence consciousness that made it a favorite tool of writers and movie makers. The depictions may have been mostly fictional, but the ideas came from how psychiatrists and police officers used the drug in their respective practices: psychiatrists to get clients to open up about repressed memories, and police officers to get confessions from criminals.

A complaint made by io9 is that the more noble origins of what came to be known as “truth serum” have gotten lost in the noise of history and public perception.3 In the early 20th century, Dr. Robert House of Dallas focused on scopolamine, a drug administered to women in labor to induce sedation and drowsiness, so as to better help women through the strain of childbirth.

But in the state of “twilight sleep” that followed administration, the women would answer any questions directed at them with unthinking and automatic responses, often involuntarily exceeding the parameters of the question.

Some physicians observed that women who answered questions in this “twilight sleep” provided accurate and candid answers, which led Dr. House to wonder if a similar approach could be used to assist in the questioning of suspected criminals.

To that effect, House made arrangements to interview two prisoners in the Dallas county jail, “whose guilt seemed clearly confirmed,” according to the Central Intelligence Agency’s article on “‘Truth’ Drugs in Interrogation.” While under the influence of scopolamine, both prisoners denied the charges that had been levied against them; at their respective trials, they were both exonerated.4

House’s theory was that the same mechanism of action that could make a woman “forget” that she was having a baby (to the point where she was able to answer questions truthfully and instinctively) could also make anyone else answer truthfully and instinctively, especially if they had nothing to hide. If the application of scopolamine could induce such honesty, then it could save innocent people from the gallows.

Unlocking Shell Shock

House’s jailhouse experiment occurred in 1922 when the world was still reeling from the unprecedented horrors of World War I. The concept of a drug that could make stressed and nervous people loosen up and talk was of particular importance to psychiatrists, who observed that returning soldiers suffering from shell shock (what we would now call post-traumatic stress disorder) had great difficulty expressing their thoughts and feelings. Some soldiers refused to talk at all, so traumatized were they by their battlefield experiences.

In the same way that Dr. House used scopolamine to remove inhibitions (either in women in the act of childbirth or wrongfully jailed men who had nothing to hide), it was found that Sodium Pentothal was the perfect anti-anxiety drug to give to depressed soldiers.

Once their trauma-inflicted mutism was unlocked, psychiatrists engaged them in talk therapy, to the point where they were given the right structure with which to deal with their mental difficulties.

The programs proved effective. The soldiers, freed from their burden, were able to reintegrate with their local communities (and, in doing so, avoided the fate that met soldiers from previous campaigns, who were often forced to spend years in rudimentary psychiatric facilities).

Word of the success stories spread, and the psychiatrists who treated soldiers were called to offer their services at police stations. In time, the connection was made between how barbiturates removed a soldier’s fear of reliving past events and how barbiturates could, in theory, remove a criminal’s fear of being caught.

But the more scientific rigor was applied to confessions under the influence of barbiturates, the less enthusiastically the results were received.

During the Cold War, the Central Intelligence Agency used scopolamine on suspected spies from the Soviet Union, as well as on their own agents in the hopes of weeding out double agents. One reason scopolamine was favored was because of its amnesiac effects: It not only wiped out the memory of the target while they were under the influence of the substance, but also the period of time immediately preceding the administration. For espionage, this way of controlling the target’s memory was (and still remains) priceless.

For extracting useful information, however, it left a lot to be desired. One of the limitations of using drugs for interrogative purposes is that questioners have to be very sure and explicit about what they want – to the point of effectively already having the answers to the questions they’re asking.

Any ambiguity in the line of attack will prompt a drugged interrogant to say things that may or may not be true.

Closeness to the Interviewer

Furthermore, someone under the effects of barbiturates will most likely simply tell the questioner whatever they want to hear. According to i09, barbiturates suppress the parts of the brain that can critically evaluate the merits of a question, to the point where the interrogant merely wants to please the person asking the question (a feeling of “closeness to the interviewer”).

Under the influence of scopolamine or Sodium Pentothal, it’s simply easier to let the imagination take over, in the same way that mild intoxication that can loosen the tongue (and the mind).

Business Insider explains that barbiturates (such as sodium thiopental, which has been used as a truth serum) work by slowing the rate of communication between the brain and the central nervous system. It depresses the body’s ability to transmit information to and from the brain, making it useful for:5

  • Pain relief.
  • Sedation.
  • Relaxing muscles.
  • Lowering blood pressure.

This also complicates performing high-functioning tasks, like walking in a straight line or even coming up with a lie. Any form of concentration is impeded by the application of barbiturates. It is similar to the state of consciousness between wakefulness and sleep, only much more powerful (due to the chemical influence).

If an interrogator wants a confession, simply boiling down to a “yes” or a “no,” this is much easier to achieve with barbiturates. But if the focus is on information – especially complex, nuanced information (as with espionage or a criminal investigation) – then drawing the lines between the interrogant being forthcoming, being imaginative, not understanding the question, and lying because it’s easier than telling the truth becomes prohibitively difficult.

This is especially the case if the questioner asks leading questions; the target will simply go in the direction of the questions, even if the truth is contrary to the line of questioning.

The Concept of Certainty

Therapists noticed the problem when they observed that their patients would eventually go along with whatever they were being told. Scientific American explains that people who have been administered barbiturates will pick up on cues from their questioner and simply repeat those back.

Similar revelations eroded the perceived usefulness of Sodium Pentothal. Eventually, researchers realized that the drug caused targets to divulge too much information, obfuscating the truth. The stream-of-consciousness style of responding while under the influence of barbiturates rendered the whole method of sorting out fact from fiction as part of the problem.

The problem, sums up i09, is that barbiturates strip the concept of certainty from the information provided by an interrogant. For intelligence agencies, police investigations, and psychiatrists, answers without certainty aren’t worth the time it takes to ask the questions.

Understandably, courts of law have taken a dim view of confessions obtained via the administration of barbiturates. Even in the first half of the 20th century, police drugging suspects with such substances caused scandals. Today, the concept of a confession being made under the imposed duress of a barbiturate, and then being used to elicit a guilty plea, could be legitimately seen as a violation of the Fifth Amendment’s protection against self-incrimination.

The Amendment states that “No person […] shall be compelled in any criminal case to be a witness against himself,” and the amnesiac and invasive properties of barbiturates (when applied in an interrogative context) have been largely regarded as infringements in the spirit laid out by the Amendment.7

The Case of James Holmes

The legality of using barbiturates in this setting was given new attention in 2013 when a Colorado judge approved the administration of a truth serum for a high-profile, and controversial, criminal trial.

In July 2012, James Holmes killed 24 people at a movie theater in Aurora, Colorado. Seventy other people were struck by bullets, making it the largest mass shooting (in terms of number of people injured) in American history until 2016. Holmes confessed to the crime, but offered a plea of not guilty by means of insanity.

In 2013, presiding Judge William Sylvester authorized the use of a “truth serum” to be used on Holmes, to determine whether he was truly of unsound mind on the night of the massacre.

The chair of the criminal justice section of the American Bar Association said that the proposal of using a truth serum to test an insanity plea “was highly unusual” in the United States, accurately predicting that the ramifications of such a measure could conflict with Holmes’s Fifth Amendment right to remain silent.

Medical experts also cast doubt on the wisdom of administering a truth serum to Holmes. A psychiatrist told The Guardian that the presence of barbiturates in a person’s system does not guarantee truthful answers, and could even pervert the course of justice “by rendering the defendant susceptible to pressure” and “outside suggestion.”

Similarly, a clinical professor of psychiatry at New York’s Columbia University pointed out that there was scant evidence to support the use of drugs to obtain the truth, especially in a criminal context.8

At the conclusion of his trial, Holmes was found guilty of all the charges against him (including 24 counts of murder and 140 counts of attempted first-degree murder). He was sentenced to 12 life sentences in prison and an additional 3,318 years behind bars. There was no administration of a truth serum during his trial.9

Suggestive Therapeutic Procedures

In writing why truth serums are closer to fantasy than fact, Salon quotes Psychology Today in saying that the entire practice of “suggestive therapeutic procedures” (also known as “narco analysis” for the way an interviewer tries to exploit a subject’s neutralized subconscious mind) is notoriously inaccurate.

Such practices can make subjects so desperate to provide information, that truth serums can go so far as to “increase the risk of false memories,” which are events that never actually took place, but the subject defends with such great conviction that the interviewer might believe the account to be true.10

The Central Intelligence Agency itself has suggested that drugs being capable of reaching into the farthest corners of the mind “has provided an exceedingly durable theme for the press and popular literature,” but immediately douses the idea.

Even the phrase truth serums, writes the agency, is an inherent misnomer: The drugs are not, by definition, serums, and the “truth” is shaky at best.

The CIA has the benefit of adopting this position after entire generations discovered that barbiturates have no worthwhile value in extracting information from noncompliant sources, and the agency itself has moved onto other methods of doing so.

LSD: The First Modern Truth Serum

But in the mid 20th century, when the dust of World War II was still settling, and the chill of the Cold War was beginning to take hold, the powers that were at the CIA had a very different opinion.

By 1946, just a year after Nazi Germany had been defeated, the word across the Pentagon was that total war with the Soviet Union was inevitable, and the United States had to defend itself by any measure, including the use biological, chemical, and atomic weapons.

The Joint Chiefs of Staff had some help: 1,500 Nazi scientists, technicians, and engineers who had been secretly repatriated to the United States as part of Operation Paperclip. The purpose of the operation was to ensure that post-war Germany would be incapable of launching any reprisals, and to deny the Soviet Union access to the Nazi think tanks.11

In 1948, Richard Kuhn – an Austrian-German biochemist and Nobel Prize winner who had collaborated with the Nazis – told his Operation Paperclip officials of a drug that Swiss chemists had developed with an eye for weaponization. The drug, a hallucinogen, was greatly valued for its ability to “incapacitate, not kill.” It went by the name lysergic acid diethylamide, or its initials, LSD.

Word had filtered through to the Americans that the Soviets themselves were using unconventional mind-control programs on their own Nazi prisoners. Believing that it was only a matter of time until the Russians would start capturing Americans, the CIA set out to fight fire with fire, developing its own form of enhanced interrogation methods.

The CIA wondered what would happen if its agents could drug captured Soviet spies with LSD, get information from them, “and somehow make them forget that they talked.”

Project MKUltra

In 1952, two Soviet spies were subjected to early experimentation. A memo sent to the Deputy Director of the CIA at the time revealed that “light dosages of drugs” (and hypnosis) induced a “complete hypnotic trance” in the patients, which rendered them unable to remember the 100-minute interrogation that followed.

The plan was to simply drug the spies, ask them questions, and then release them, satisfied that the resultant amnesia would clear up any loose ends. The reality, writes the Daily Beast, was that from the questionable results and anti-Soviet paranoia arose “one of the most notorious CIA programs of the Cold War,” the infamous Project MKUltra.

The lengths the CIA went to with MKUltra became the subject of government investigations and controversial declassifications, all of which revealed that the much-vaunted application of LSD (and, later, barbiturates) to spies did not produce the desired results.

Tiring of the unpredictable and unreliable responses, the CIA quietly shelved its use of LSD and barbiturates, and focused on other forms of interrogation (of equally questionable effectiveness and legality).

However, the idea of using substances to control the minds of spies and soldiers, Russians and Americans alike, proved fertile ground for storytelling. Movies like Jacob’s Ladder and The Manchurian Candidate explored the idea of brainwashed sleeper agents being “reactivated,” a concept popularized in the modern Jason Bourne movies.

Television shows, such as The X-Files, Fringe, and the 2016 hit Stranger Things have provided topical updates to the concept of MKUltra, often using the War on Terror as a modern-day analogy for the climate of the Cold War.12

Wishful Thinking

But despite the gripping drama and fantastical scenarios, the use of barbiturates as “truth serums” is one place where the truth is not as strange as the fiction.

A BBC reporter who willingly underwent sodium thiopental administration to test its effectiveness wrote that such drugs do make people more inclined to talk, but what they say could be a word salad of wishful thinking, responses to suggestions made by the interviewer, and maybe a grain of reality.13

Even newer methods employed by the CIA and intelligence agencies to break through the barrier of lies, as part of their information-gathering, have been met with skepticism.

One of the attorneys of a special prosecution team to try terrorist detainees at the Guantanamo Bay Naval Base told PBS that, with the right techniques, he could get a person to admit guilt to any accusation that was levied, but the confession would be worthless.

Whether out of fear of pain, fear of the threat of pain, or compromised cognitive skills, there is a part of the human consciousness that remains impenetrable to torture or truth serums – for now.

If you or someone you care about are struggling with drug use, help is available. At Sunrise House—an inpatient rehab facility in New Jersey—we offer evidence-based addiction treatment that is personalized for each person’s needs. To start treatment, call or begin the admissions process by online.

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