Does 'Truth Serum' Actually Work?

If you believe bazillions of spy movies, novels, and Stranger Things, you'd better not ever get captured by the enemy and injected with truth serum because you'll sing like a canary and you'll probably also act ridiculous and confess your feelings for a coworker in between bouts of vomiting while sitting on the floor of a public toilet. Yes, truth serum is not to be messed with, but hey, it beats medieval torture, which was standard practice long before truth serum became a thing.

Truth serum might not actually be a thing, though. According to Gizmodo, its real name is "sodium pentothal," and it's a barbiturate, which works by depressing the central nervous system. People under the influence of sodium pentothal become calm, drowsy, and pain-free. But do they also become truthful? That's not something anyone can agree on, even today.

Funnily enough, sodium pentothal became famous for its supposed truth-giving properties after 1915, when Dr. Robert House noticed that his patients often answered questions in a strangely automatic and unthinking way when they were under the influence of the drug. House thought maybe the drug would help exonerate innocent prisoners — if people under its influence spoke only the truth, then it could help keep innocent people out of prison. Once law enforcement latched onto the stuff, though, it didn't really go that way. Instead, it was used as a way to get guilty people to confess, and sometimes as a way to coerce a confession out of a possibly innocent person.

And here's the worst part — the best we can really say about sodium pentothal's value as a "truth serum" is that it might work. It can make a person disoriented, and a disoriented person might be disoriented into saying something he or she might not otherwise have said. But it's actually more likely that people under the influence of the drug are going to say what they think their interrogator wants them to say, rather than the actual truth. So at best, truth serum is only partially effective. And if you need further proof that it's just not a reliable way to get information, well, the Supreme Court considers confessions given under the influence of sodium pentothal to be "coerced," and therefore unconstitutional. So the short answer to the question "does truth serum work?" is nope. It made for a fun episode of Stranger Things, though.