The hallucinogenic drug lysergic acid diethylamide, or LSD, was discovered by the Sandoz drug and chemical corporation in 1943, and within a few short years both the U.S. military and the newly formed CIA would be investigating the possible strategic value of this extraordinarily powerful new substance.

Since a single dose was merely 100 micrograms or so, 10 kilograms—about the amount that could fit into an agent’s carry-on luggage, for instance—was equivalent to 100 million doses, or enough to incapacitate the entire population of either the United States or the Soviet Union.

Its strategic importance as a weapon was thus all too evident, but the CIA was more interested in its potential as an interrogation aid or even as a possible “mind-control” tool. Leaving the research into large-scale deployment to the military’s chemical and biological warfare (CBW) division, the CIA began an extensive program of testing the drug on individuals.

U.S. intelligence organizations had long been interested in the possibility of mind control. The CIA’s World War II predecessor, the Office of Strategic Services (OSS), had experimented with marijuana as a possible mind-control agent. And Stanley Lovell, head of OSS research and development, looked into the possibility of hypnotizing German prisoners and sending them back to Germany with orders to assassinate Hitler.

Though nothing much came of these efforts, the Communist trials of the late 1940s, which saw political and military officials confessing to treasonous acts they clearly did not commit, convinced the CIA that techniques for radical behavior modification existed and, worse, that the Soviets had developed them first.

With the perceived threat of Soviet mind control looming on the horizon, in 1953 the CIA set up MK-ULTRA, a new project headed by Sidney Gottlieb that was devoted to studying the operational potential of biological and chemical materials (including LSD).

The CIA’s testing of LSD proceeded on two fronts. On the one hand, they decided to make use of as many official medical research organizations as they could, and began funding (often covertly) research on LSD in universities, hospitals, and drug treatment centers. On the other hand, they also decided that they needed unwitting subjects whom they could drug and then observe and even interrogate.

The CIA’s need for unwitting subjects was so intense that agents within project MK-ULTRA agreed that they could slip each other the drug at any time. This policy of unwitting testing produced what has become one of the most publicized events in the project’s history: the LSD-related suicide of Dr. Frank Olson of the Army Chemical Corps’ Special Operations Division (SOD).

Olson had a profoundly negative reaction to the drug, which had been given to him without his knowledge, and Gottlieb, rather than offering Olson proper psychiatric help, sent the disturbed SOD man to one of MK-ULTRA’s own scientists, an immunologist and allergist who had no psychiatric experience.

The MK-ULTRA scientist was unable to salvage the situation, and Gottlieb was forced to cover up the entire incident after Olson jumped through the window of his tenth-floor hotel room. Rather than slowing down the CIA’s experiments with LSD, however, the Olson case merely made them realize that they needed to start using different subjects.

Gottlieb arranged to have “safehouses” set up in New York and San Francisco where LSD was administered to unwitting prostitutes, drug addicts, and small-time criminals (i.e., those who would be least likely to report the CIA agents to the police).

As the agents developed close relationships with the prostitutes, they realized that it was just as easy to pay the women to lure unsuspecting clients back to the safehouse for testing as it was to test the prostitutes themselves.

Furthermore, while they were at it, the CIA operatives decided to use the prostitutes for a variety of explorations into deviant sexual practices that might have future operational value. The prostitutes who participated in what the CIA code-named “Operation Midnight Climax” were paid $100 a night for their work.

In the mid-1970s tales of these covert domestic operations emerged as a result of both investigative reporting and government inquiries such as the Rockefeller Commission in 1975 and the Senate Select Committee on Intelligence in 1977.

The CIA agents’ cavalier approach to drug-testing horrified the public, but the institutional programs they covertly funded were often just as shocking. In Lexington, Kentucky, the director of the Addiction Research Center offered addicts heroin if they “volunteered” for the LSD testing project.

Some patients were kept on LSD for seventy-seven consecutive days. At McGill University in Montreal patients were subjected to extensive “depatterning”—a technique the CIA saw as a possible prelude to mind control—that involved extensive use of LSD, electroshock therapy, and sensory deprivation.

Patients’ LSD-induced ramblings would be recorded on tape, then, later the patients would be injected with more LSD combined with either depressants or stimulants and left alone in a room to listen to their earlier tape.

In the end, the CIA became convinced that LSD would not turn out to be the effective mind-control agent they had hoped it would be. And while they still dreamed of administering it to foreign leaders in order to produce erratic and discrediting behavior (one of Fidel Castro’s cigars was to be coated with the drug), they discontinued the research begun in the 1950s by the time the inquiries of the 1970s had begun (or so they claimed).

In the meantime, LSD had become an important part of the 1960s counterculture, and no doubt this new social significance is the reason why tales of the CIA’s connection to the drug were so endlessly fascinating for the public. (No one seemed to talk quite as much about the CIA’s experiments with Seconal and Dexedrine, for example.)