How do “truth” serums work?
“Truth serum,” the chemical thiopental sodium, is a fast-acting barbituate that makes a person talkative, uninhibited, and extremely open to suggestion. It does not make a person “tell the truth,” but they can be coaxed into saying things the interviewer wants them to say. The effect of this drug is similar to acute alcohol intoxication. Technically, thiopental sodium increases the permeability of the neural membrane to chloride ions. This results in general inhibition, starting with the cortex and progressing to other regions of the brain. Thiopental sodium is used now as an induction to anesthesia (generally given before nitrous oxide, as many people are apprehensive about inhaling the gas first), by itself for minor operations, as an anticonvulsant, as an animal tranquilizer, as a radioprotective agent, and as the first drug given in a lethal injection.
