The CIA's Hunt for Truth Serum: The Cold War Science of Chemical Interrogation

0:01 Truth theorem. We've seen it a lot on TV shows. But can someone be forced to tell the truth? In Marvel's Ant-Man and the Wasp, there's a particularly funny interrogation scene involving the characters insist it's truth theorem. The criminals administering the injection believe their chemical cocktail would force their prisoner to reveal everything. The idea isn't unique to Marvel, though.

0:25 It's been around for decades. In True Lies, Schwarzenegger's character receives an injection intended to make him talk Television thrillers such as Alias have also explored chemical interrogation, and I even believe The Americans, the spy show from years ago. But can it? The answer is actually no. At least no drug has ever been scientifically demonstrated to reliably distinguish truth from deception or compel someone to provide accurate information.

0:52 One substance historically associated with truth serum is sodium thiopental, or also called sodium pentothal. Thiopental belongs to a class of drugs known as barbiturates. The medications enhance the activity of GABA, or the brain's primary inhibitory neurotransmitter. Essentially, GABA helps reduce neuronal activity. When thiopental increases GABA's inhibitory effects, the brain becomes less alert. Judgment deteriorates, anxiety may decrease, and the person can become less inhibited. At higher doses, the medication produces unconsciousness. It was only wildly used to induce general anesthesia. But at lower doses, individuals may become unusually talkative. This observation is what established the myth of

1:36 truth serum. Unfortunately, reduced inhibition doesn't guarantee honesty. A person under the influence of phenylpentol might review genuine information, or they may fabricate a story, or describe something that never happened and unknown to them. Another drug investigated for similar purposes was scopolamine. Unlike thiopental, scopolamine interferes with acetylcholine, a neurotransmitter essential for memory and attention. By blocking the muscarinic acetylcholine receptors, scopolamine can produce confusion, disorientation, and impaired memory formation, and that creates a major scientific problem. How can investigators trust someone's answers when the substance they're administering may interfere

2:21 with the person's ability to remember correctly? This is where Hollywood science intersects with actual intelligence history. During the Cold War, the CIA launched a secret research program known as MKUltra. Beginning in 1953, the program investigated whether drugs, hypnosis, or other techniques could influence behavior. Researchers experimented with substances, of course, like LSD, often through profoundly unethical methods involving people who had never given consent. The CIA was interested in questions remarkably similar to those presented in fictional spy thrillers. But could chemicals lower resistance to questioning? Could they disrupt a person's judgment? But the program never demonstrated the existence of

3:02 a reliable truth serum, and there's another reason. Human memory is not a recording device. Memories are reconstructed through complex interactions involving the hippocampus, cerebral cortex, and other systems. Sedatives and psychoactive substances can disrupt attention, encoding, retrieval, and the ability to distinguish actual experiences from imagined ones. A chemically impaired individual might sound confident while providing completely inaccurate information.

3:29 The CIA director in 1973 ordered the destruction of many MKUltra records, leaving important gaps in the historical record. Congressional investigations later exposed portions of the program. Those missing records have also helped fuel decades of speculation and conspiracy theories. But the documented experiments are disturbing enough without inventing more claims.

3:50 That brings us all the way back to Ant-Man. The fictional truth serum works because the screenplay requires it. In reality, though, chemicals can alter consciousness, reduce inhibition, and impair memory. What they cannot do is distinguish a truthful statement from a false one.