Sodium pentothal is used in something called a narco test in India. Why not any other drug?

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I think its use has been replaced by something else by now in most parts of the world, but why do they choose the drugs they choose for “truth serum” purposes?
(The results of a narco test aren’t admissible in court)

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Anonymous 0 Comments

If you inject someone with enough sodium pentothal they will initially become unconscious as the sodium pentothal turns most of their brain off.

As the sodium pentothal wears off, the person’s brain begins to slowly turn back on. The first parts that turn on are the parts of your brain responsible for the basic functions involved in being awake, while the last parts that turn on are the parts responsible for thinking. During that turn back on period, there is a twilight phase where the person is awake enough to respond to simple questions, but not so awake that they are capable of actively trying to deceive you.

Because they can’t really lie, people have a high chance of responding truthfully to questions they are asked. Its not a 100% thing and there are several common issues:

1) People often babble incoherently and may continue babbling in response to a question.

2) People in that state are easily confused and may answer a different question than what they asked.

3) Sodium Pentothal interferes with memory, so people may not remember the answer to the question but, nonetheless, try to answer without indicating their inability to remember the correct answer.

In other words, the mechanism by which sodium pentothal causes people to give truthful answers is by disrupting brain activity. One of the other consequences of disrupting someone’s brain activity is that, due to the effects of the drug, the person temporarily thinks the answer they gave is correct, even though its really nonsense.

That doesn’t mean its a completely useless technique, but its really only useful for confirming things that you already have a pretty good idea about. IE, you strongly believe that Joe is your subject’s friend. When you ask them who their friend is, they say Joe. The likelihood of their friend being Joe just went up substantially.

Conversely, if they say their friend is named Steve, but you have no idea who Steve is, then that doesn’t mean much. It could be that their friend actually is Steve and not Joe. It could also be that Steve is just the first name that came to their mind and, in their drug induced twilight state, they assumed that meant that Steve was their friend when, in fact, Joe is.

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