---
category: Intelligence Operation
created: 2026-06-03
end: 1962-11
location: Far East
start: 1962-08
summary: Army field test of LSD in interrogations in the Far East, August to November
  1962, on seven foreign nationals suspected of narcotics dealing or intelligence
  work; one subject was left semicomatose.
tags:
- Project
- Army
- MKULTRA
- LSD
- Interrogation
- ColdWar
updated: 2026-09-22
---

DERBY HAT was the second series of field tests of the Army's Material Testing Program EA 1729, conducted jointly by the Army Intelligence Board and the Chemical Warfare Laboratories to evaluate the intelligence uses of [LSD](/concepts/lsd/). After laboratory tests on 95 volunteers at Edgewood Arsenal, the Army's Assistant Chief of Staff for Intelligence authorized operational field testing in 1960. The first series, [Operation THIRD CHANCE](/programs/operation-third-chance/), was run in Europe from May to August 1961 on ten subjects.[^1]

### The Tests

An Army Special Purpose Team conducted DERBY HAT in the Far East from August to November 1962. Its seven subjects were all foreign nationals "either suspected of dealing in narcotics or implicated in foreign intelligence operations." Its purpose was "to collect additional data on the utility of LSD in field interrogations, and to evaluate any different effects the drug might have on 'Orientals.'" None of the subjects of the field tests were volunteers, and none knew they were to receive LSD.[^1]

In September 1962 a suspected Asian espionage agent was given 6 micrograms of LSD per kilogram of body weight, the dose completed at 10:35 in the morning. The medical report records that by 11:20 "sweating became evident, his pulse became thready," that he "began groaning with expiration and became semicomatose," and that at 12:30 "he began moaning he wanted to die and usually ignored questions." For three hours further attempts at interrogation "yielded no relevant answers." The Senate subcommittee called it "another gross violation of an individual's fundamental rights."[^1]

### The Record

The tests were described in the 1976 report of the Army's Inspector General, "Use of Volunteers in Chemical Agent Research," and in the staff material printed with the Senate hearing of August 3, 1977, on MKULTRA, which found that the Army's programs "duplicated research which had already been conducted by the CIA" and suffered from "a lack of clear authorization and supervision."[^1] Asked about DERBY HAT and THIRD CHANCE in his Top Secret testimony to the [Church Committee](/events/church-committee/) in October 1975, [Sidney Gottlieb](/people/sidney-gottlieb/) did not recall the operations but said that during the [Vietnam War](/events/vietnam-war/) the military was "considering the use of LSD on a fairly large scale," which he explained as "interrogating a number of prisoners," and that the agency was asked to consult on it.[^2]

[^1]: U.S. Senate, Select Committee on Intelligence and Subcommittee on Health and Scientific Research of the Committee on Human Resources. *Project MKULTRA, the CIA's Program of Research in Behavioral Modification,* joint hearing, 95th Cong., 1st sess., August 3, 1977, appendix, pp. 411-416, citing Inspector General of the Army, "Use of Volunteers in Chemical Agent Research," March 10, 1976, and the DERBY HAT "Medical and Pharmacological Report: Case #1," September 20, 1962. https://www.intelligence.senate.gov/sites/default/files/hearings/95mkultra.pdf
[^2]: National Security Archive. "Top Secret Testimony of CIA's MKULTRA Chief, 50 Years Later." October 30, 2025, documents 1-4 (Gottlieb's testimony of October 15-18, 1975). https://nsarchive.gwu.edu/briefing-book/dnsa-intelligence/2025-10-30/top-secret-testimony-cias-mkultra-chief-50-years-later