For decades, the U.S. Army conducted secret clinical experiments with psychochemicals at Edgewood Arsenal. In the nineteen-sixties, Army Intelligence expanded the arsenal’s work on LSD, testing the drug as an enhanced-interrogation technique in Europe and Asia. This companion piece to “Operation Delirium,” which ran in the December 17th issue of The New Yorker, documents the people who were involved and what they did.

Dr. Van Murray Sim, the founder of Edgewood Arsenal’s program of clinical research on psychochemicals, was a man of deep contradictions. He was a Navy veteran, but he worked at the Army post as a civilian. For the doctors who worked with him, he was like Dr. Strangelove; he was a leader; he was the “Mengele of Edgewood”; he was a good old soul. Sim could be manipulative and vengeful, ethically shortsighted, incoherently rambling, rashly slipshod in his methods, but he was also fearless and ambitious and devoted to chemical-warfare research. He was gargantuan—his body exuded forcefulness, like an oversized rook on a chessboard—but he was willing to allow himself to be rendered helpless. In 1959, he was the first person to be given VX, a highly lethal nerve agent. As the drug began to take effect, Sim became irrational and started to thrash around. “I was having difficulty with vision, seeing—a distortion of vision, sweating, tremors, nausea, vomiting,” he later recalled. His face grew pale. He eventually stopped talking and descended into a world of his own imaginings.

Not everything that Sim sampled was so deadly; he also kept unauthorized vials of Demerol, which he used habitually, in his travel case. He had taken LSD several times, and also Red Oil, a highly potent synthetic version of marijuana. The drugs were being tested at the arsenal for use in “psychochemical warfare”—a concept, developed at Edgewood in the nineteen-forties, that entailed a search for mentally incapacitating chemicals to replace guns and grenades on the battlefield. Sim once mixed a milligram of crystallized psilocybin—a drug found in hallucinogenic mushrooms—with water and drank it as if it were lemonade. He saw people nearby turn sickly green. “I feel very light, almost weightless,” he pronounced. “And, for me, that’s quite a trick.”

These self-experiments—with their egocentricity and their daring—helped give Sim the status of a minor military legend. At the time, the clinical research at Edgewood was conducted on soldier volunteers, recruited from around the country. “He became a guinea pig,” a general testified before Congress in 1959. “He got pushed around by the other doctors just as any other volunteer would. And once he entered that chain of events he was no longer the head of the laboratory. He was just a little boy in a cage.”

The testimony was meant to underscore Sim’s sacrifice. And yet, even as Sim was being heralded before Congress, he was running a series of remarkable LSD experiments, designed to administer drugs to people who had no idea that they were getting them. In this way, Sim helped guide the arsenal’s clinical research into the murky world of intelligence, interrogation, even torture. The work was given a special code name, Material Testing Program EA 1729. It was carefully kept secret, even on the grounds of the arsenal.

Sim began to pursue the use of psychochemicals for intelligence purposes soon after he arrived at Edgewood, in 1956. That February, he travelled to New York, to meet with Sidney Malitz, the acting chief of psychiatric research at the New York State Psychiatric Institute. Edgewood periodically sent samples of drugs to the institute for testing on patients and volunteers, each chemical marked with an Edgewood Arsenal, or EA, code. In 1953, a catastrophic amount of EA 1298—a version of mescaline—had been injected into a patient named Harold Blauer, who had a violent reaction: shock, coma, and then death. Blauer, a professional tennis player, had been admitted to the institute for depression, and was never told that he was part of a military experiment. The researchers at the institute were scarcely better informed. One later confessed, “We didn’t know whether it was dog piss or what it was we were giving him.” At Edgewood, Blauer’s death was treated as a case study in toxicity. “This lead will be pursued,” an official at the arsenal noted.

Sim knew of the death—an account of the case was kept in a sealed file that only he had the authority to open—but he maintained a relationship with the institute. By the time he met with Malitz in New York, the Army was interested primarily in LSD—known as EA 1729. Malitz agreed to test LSD and similar drugs on volunteers or “selected patients,” in order to determine how people would react during phony interrogations. He offered to use hypnosis to plant secrets in subjects’ minds. Then, he said, “one of the hallucinogens will be administered and an attempt made to see if the patient will reveal the information.”

Sim indicated that he would consider the offer. Three months later, he obtained permission to test psychochemicals at the arsenal itself. LSD’s effects were still little understood; as Sim acknowledged, it was possible to become “smothered by the preponderance of conflicting reports.” Within that morass, there was evidence that the drug posed genuine health risks. “The observations of certain British investigations on normal volunteers and reliable reports from their colleagues suggest that during acute LSD intoxication the subject is a potential danger to himself and to others,” Sim wrote in an early report. “In some instances a delayed and exceptionally severe response may take place and be followed by serious after-effects lasting several days.”

Researchers at Edgewood began by conducting basic studies. Joseph Bertino, who served as a Medical Corps officer at Edgewood from 1956 to 1958, joined three other researchers to explore LSD’s effect at incrementally higher doses. Measuring the drug in micrograms per kilogram, or mcg/kg, they worked their way up to 16 mcg/kg—a huge amount, at which subjects could not even repeat a short sentence, exhibited signs of hypertension, and occasionally vomited or hyperventilated. One man saw “horrible green-eyed monsters” everywhere; another felt “a constant flow of electricity throughout his body.” Bertino told me that careful psychological screening of subjects before these kinds of tests prevented serious reactions, but that there were instances at the arsenal of “subjects who were kind of slightly paranoid to start with who became psychotic.”

The drug was unpredictable. “We could give exactly the same dose of a drug that was produced in the chem lab—so it was clean and absolutely the same—and we could see absolutely tremendous differences in the reactions of the volunteers,” a former Edgewood staff member recalled. Even after the experiments, some subjects demonstrated unusual behavior. Another former member of the Medical Corps, who used to bunk with the volunteers, told me that he woke up one night to find one of the men holding a hospital scale over his head. “He didn’t have a clue,” he recalled. By luck, he was not crushed. He calmed the soldier down and guided him back to his bunk.

In 1957, Sim began talking with the Army Intelligence Board about researching LSD in a series of “practical experiments.” The goal of psychochemical warfare is simply to disable one’s enemy. But to use a drug in interrogation one has to penetrate the individual mind—not shut it down but force it open—and an enemy who knew the effects of a drug might be better able to resist it. At Edgewood, it was deemed important to conduct LSD tests on people who were provided with no information about what the drug would do. In 1958, a soldier who had come to the arsenal thinking that he would be testing gas masks was dosed with LSD during an interview with a doctor, who casually sipped some water and encouraged him to do the same. Some soldiers reacted with confusion; one lunged at an officer, not knowing why.