A truth drug is a drug used for the purposes of obtaining
accurate information from an unwilling subject, most often by a police, intelligence,
or military organization on a prisoner.
Drugs used for the purpose of obtaining the truth from people
have included alcohol, scopolamine, and sodium thiopental (more
commonly known as sodiumpentothal)—all sedatives that interfere particularly
with judgement and higher cognitive function. Whilst alcohol is used by
this purpose by many individuals in a more innocent sense, it is apparently
used by professionals in the areas as well. A book by a former Soviet KGB officer
based in Washington, Washington Station, details the use of near-pure
alcohol to verify that a Soviet agent was not compromised by US counter-intelligence
The CIA's MK-ULTRA Project
The United States Central Intelligence Agency conducted a
series of experiments in the 1950s and 1960s, collectively known as the MK-ULTRA
Project, designed to find a perfect truth serum for use against Soviet agents.
Initial efforts focused on LSD and doses of barbiturates and then amphetamines
given in rapid succession, but the project was ultimately abandoned after mixed
Whilst fictional accounts of intelligence interrogation gives
these drugs near magical abilities, information obtained by publicly-disclosed
truth drugs has been shown to be highly unreliable, with subjects apparently
freely mixing fact and fantasy. Much of the claimed effect relies on the belief
of the subject that they cannot tell a lie while under the influence of the
Use of truth drugs today
As of 1993 in Canada these were still used to help diagnose
schizophrenic subjects, especially paranoia where the difficulty was to get
the subject to talk at all. Subjects experienced with other hallucinogenic drugs
reported similarity of effects of sodium amytal to that of LSD or psilocybin,
but for a 20 minute period.
Interest in their use outside intelligence services has since
declined to negligible levels—though their use has been reexamined after the
September 11, 2001 Terrorist Attacks. It is possible, but thought unlikely by
experts in anaesthetics (the drugs most closely resembling truth drugs in common
use), that intelligence services do have more effective such drugs at their
disposal which they have not disclosed.
Psychologist World is an online magazine dedicated to psychology, providing theory and experiment overviews, popular psychology articles and practical psychology guides. For details of content available with membership click here.