Truth serum: does this drug really work?

Drugs such as sodium pentothal have been used in interrogations to obtain confessions.

The idea of gaining access not only to people's control but also to the information they might be hiding is so appealing that the concept of "truth serum" has become so popular that it has been used in the field of interrogation. the concept of "truth serum" has become very popular and well known.. 

It has been presented as a liquid whose potential to achieve perverse ends is difficult to imagine at all, and with effects as simple as its method of use: get someone to drink it and, shortly afterwards, start an interrogation in which what we will hear will correspond entirely with what the interrogated person reliably believes he knows. The option of lying will have disappeared.

Depictions of truth serum seem idealized in works of fiction such as Harry Potter (under the name Veritaserum), but in real life it has also been a substance used, especially by intelligence services, in its sodium pentothal variant.. Now, do these kinds of substances really work?

The history of truth serum

At the beginning of the 20th century, it was reported that scopolamine, also known as burundanga, a substance that was administered to women to help them endure labor pains, made them become much more uninhibited and they began to talk about intimate details of their lives with people they did not know.

In the absence of a cognitivist psychology and a scientific perspective based on neuroscience, it was psychoanalysis, the dominant paradigm at the time when talking about mental processes, that offered an explanation of how this truth serum worked.

By resorting to the ego structures of the psyche, it was proposed that certain substances, upon entering the organism, caused the ego to be neutralized and consequently and therefore unable to repress the forces coming from the Ego, so that neither morality nor the ego could be repressed.Thus, neither morality nor the expectation of not "getting into trouble" was a barrier to the emergence of many of one's innermost thoughts to the surface.

It was later, when we began to know how psychotropic drugs work, that we began to understand the mechanism by which truth serums work... and why they are ineffective.

Entering the nervous system

Basically, truth serums such as sodium pentothal are central nervous system depressants. This means that, because of their chemical composition, they cause various parts of the brain to be less activated and, consequently, the executive processes related to how we control where our focus of attention goes and what kind of actions we should avoid are relaxed, as if they let our guard down.

That means that there are virtually no significant differences between, for example, sodium pentothal and any other hypnotic drug, in the sense that its characteristic effect is drowsiness, sedation and altered states of consciousness.. 

Seen in this way, it makes sense that it produces disinhibition in the content of what is said, because with that substance circulating in the brain it is practically impossible to take into account what kind of things are not appropriate in a given context, the networks of neurons that work together creating our thoughts are so numb that they cannot perform several complex actions at the same time, such as the evocation of an idea and at the same time the need not to say it.

Sodium pentothal and true confessions

But what theoretically characterizes the truth serum is not simply disinhibition, but the certainty of the content of what is said. In that sense, both sodium pentothal and all other similar barbiturates fail miserably.

Why is that? Among other things because a truth serum is still a psychotropic drug.It is not an intelligent entity; it simply circulates through our organism, coupling itself where its chemical characteristics allow it to do so and passing by (or transforming itself into other components) in the rest of the cases.

That means that it has no way of detecting neurochemical processes specifically related to truth, it simply "fits" into certain slots, for better or for worse. That is also why sodium pentothal, like any drug, not only produces the expected effect that the doctor or military officer who is supplying it is trying to achieve, but also generates various side effects of greater or lesser intensity.

In the case of pentothal, this substance is coupled to several receptors of a neurotransmitter called GABA, which is a depressant of brain activity, and acts by mimicking it, which means that it reinforces the effects of a substance that is already present in our body. The consequence of this is that one enters a state of drowsiness in which "it's all the same" and factors such as social norms and concern for one's image lose much of their importance. factors such as social norms and concern for one's image lose much of their importance..

The most absurd interrogations

In conclusion, the use of truth serum, besides being unethical as such, can at most serve to make the interrogated person start talking inconsistently, without paying attention to whether what he is saying is true or not.

It may relax the defenses that separate his thoughts from what he is saying, but it will also be true that the quality of the questioned person's speech will be affected.But it will also be true that the quality of his thoughts, in terms of their relationship to reality, will have plummeted.