Could truth serum really exist?

Kathryn Harkup, aside from your latest venture into the world of James Bond, you have also written books on some of the prominent serums and chemicals found in popular culture. One of the more commonly touted examples found in the spy genre is the ‘truth serum’, a mystery substance capable of loosening anyone’s tongue. But Kathryn, is there actually such a thing as a truth serum, such as sodium pentothal? If so, then how does it work?

Chris - Kathryn, let's come back to you, author of Super Spy Science and the world of James Bond. You've also written books on some prominent serums and chemicals that are found in popular culture. One of the common ones in the spy genre is truth serum, a mystery substance capable of loosening tongues, but is there such a thing? And if so, what is it, how does it work?

Kathryn - I think a lot of people have tried to develop truth serums. It would be extremely useful in questioning if you just know whatever was coming out of someone's mouth was the absolute unadulterated truth. And I think the idea behind a lot of these serums or compounds was that it would relax your inhibitions. So you would talk more freely perhaps a bit like if you're under the influence of alcohol. So in which case you might as well get your interrogatee drunk as opposed to giving them sodium pentothal or whatever drug. For a long time, sodium pentothal was used, allegedly, as a truth serum, basically because it would lower inhibitions, but you could just be talking like a drunk person: the first piece of nonsense that comes into your head. So if it's reliably truth or not, I don't know. As far as I know, there's no real truth serum out there, but of course they wouldn't tell me if there was.

Chris - You should give them some truth serum then!