Sidney Cohen

Sidney Cohen’s career was defined by a tension he refused to resolve too quickly: LSD might support profound therapeutic change, yet the meanings patients found under its influence could be shaped by the expectations of the people treating them. A pharmacologist turned clinician and researcher, he helped develop therapeutic uses of LSD in Los Angeles, examined its dangers in clinical and public settings, and repeatedly challenged the boundary between scientific evidence and spiritual interpretation. His importance lies not in a simple conversion from skeptic to believer, but in his continued effort to hold promise and doubt together.

Background and a Changed Model

Born in 1910 in New York City to Lithuanian Jewish immigrants, Cohen trained in pharmacology at Columbia University and served in the U.S. Army Medical Corps in the South Pacific during World War II. In 1953, while preparing a review article on chemically induced psychoses, he encountered LSD, a drug that seemed to offer a way to study the relationship between chemistry and psychosis. Like other researchers, he initially approached it through the psychotomimetic model: the expectation that the drug would produce a temporary likeness of mental illness.

Cohen tested that expectation himself in October 1955. Rather than feeling trapped in a madman’s mind, he experienced what he understood as profound tranquillity and a sense of access to enduring truth. The experience convinced him that LSD’s effects could not be adequately described as temporary psychosis. Betty Eisner later said that Cohen came to call this state unsanity, meaning a condition beyond the control of the ego. His personal experiment thus became evidence against the framework that had first brought the drug to his attention.

That reversal unfolded within a larger challenge to the psychotomimetic model. Volunteers sometimes had difficult or harrowing experiences, but few displayed the full psychosis the model predicted; even the reported twelve-hour ordeal of Mr. Katz included pleasure and insight. Cohen’s experience did not prove that LSD was safe or that every intense experience was therapeutic. It did, however, make it harder to treat distress, unusual perception, and spiritual meaning as interchangeable signs of illness.

Clinical Work in Los Angeles

By the mid-1950s, Cohen was among the leading figures in a loosely connected Los Angeles research community that included Eisner and Oscar Janiger. Beginning in 1956, he worked with Bill Wilson, cofounder of Alcoholics Anonymous, who wanted to know whether LSD might help recovering alcoholics undergo the kind of spiritual awakening he believed could support sobriety. Humphry Osmond connected Wilson with Cohen, an internist at Brentwood VA hospital who later worked at the University of California at Los Angeles. Wilson’s sessions with Cohen and Eisner strengthened his belief that LSD could occasion such an awakening. He nevertheless rejected the idea that the experience resembled delirium tremens. Although he saw a possible place for LSD therapy in Alcoholics Anonymous, the fellowship’s board opposed endorsing a mind-altering drug.

Cohen, Eisner, and Janiger also incorporated LSD into weekly psychotherapy sessions, gradually increasing the dose as treatment proceeded. Their patients included people with neuroses, alcoholism, and less severe personality disorders, as well as painters, composers, and writers. The therapeutic rationale was that LSD could bring repressed emotions and memories of childhood trauma within reach; the extension to artists rested on the related idea that access to the subconscious might foster creativity. These were not interchangeable aims: one concerned relief through psychotherapy, the other the possible expansion of creative work.

The group reported encouraging early results. Sixteen of its first twenty-two patients showed marked improvement, according to Cohen and Eisner. A 1967 review of psycholytic therapy studies published between 1953 and 1965 estimated success rates of 70 percent for anxiety neurosis, 62 percent for depression, and 42 percent for obsessive-compulsive disorder. Those figures made the approach appear promising, but few, if any, attempts had tested the results in controlled trials. Cohen’s work therefore sits at the intersection of therapeutic optimism and a persistent evidentiary limitation: reported improvement was substantial, while the means of establishing how much the treatment itself caused remained weak.

Suggestibility and Scientific Doubt

As LSD therapy attracted wider attention, Cohen grew uneasy about the religious and magical aura surrounding the drug. He remained interested in what patients experienced, but worried that the setting and the therapist’s beliefs could influence the account that emerged. He observed that Freudian patients tended to return with interpretations framed around childhood trauma, sexual drives, and Oedipal emotions; Jungian patients reported archetypes associated with the collective unconscious; and patients treated in the tradition of Otto Rank described birth-related memories. In Cohen’s view, the therapist’s favored theory could be confirmed in the patient’s report.

He treated this suggestibility as a scientific problem without assuming it automatically invalidated therapeutic benefit. If patient and therapist shared an explanation and found it useful, he considered, that explanation might function as insight even if its objective truth could not be established. He also recognized the unsettling implication: therapy could approach shamanism or faith healing, where belief and expectation form part of the process. The possibility that LSD acted as an active placebo, amplifying mental processes that were partly self-generated, offered one way to describe the uncertainty, not a final resolution of it.

This ambivalence marked Cohen off from both uncritical promotion and blanket rejection. He believed the drug could help, yet resisted treating a meaningful experience as proof of a particular theory. In a 1959 letter, he described LSD as having opened a door from which researchers should not retreat merely because the threshold felt unscientific. The image captures the tension in his position: the experience might lead beyond familiar scientific categories, but discomfort with those categories was not a reason to pretend the evidentiary questions had disappeared.

Research on Benefits and Risks

Cohen’s assessments of LSD’s safety changed as its use spread beyond closely supervised clinical work. Beginning in 1960, he published studies based on evidence rather than choosing only the anecdotes that supported one side of the debate. In his first survey, he collected information from forty-four researchers on roughly five thousand people who had taken LSD or mescaline across twenty-five thousand occasions. He found two credible reports of suicide and several temporary panic reactions, but no evidence of serious, prolonged physical side effects. For use administered by qualified therapists and researchers, he judged complications surprisingly infrequent and described LSD and mescaline as safe.

His follow-up evidence led him to draw a sharper distinction between supervised treatment and casual or irresponsible use. In a 1962 article, he warned that use outside clinical settings was producing serious complications and occasional catastrophic reactions, including risks of suicide, prolonged psychotic reactions, and antisocial behavior. The following year, he reported psychotic breaks and an attempted suicide, along with the case of a boy who took LSD from a sugar cube his father, a detective, had confiscated. The boy experienced visual distortions and anxiety for more than a month before recovering. Cohen’s account prompted Roy Grinker, editor of the journal in which it appeared, to condemn psychedelic research in an accompanying commentary, even though Cohen continued to see therapeutic potential in responsible clinical practice.

In 1966, Cohen reported additional casualties, including two accidental deaths: one by drowning and another after a person walked into traffic shouting a warning. These cases formed part of a growing public alarm, but Cohen’s position remained more discriminating than the surrounding debate. He neither used evidence of harm to erase possible clinical value nor invoked therapeutic promise to dismiss the dangers of uncontrolled use.

Public Advocacy and Legacy

Cohen continued to support a possible medical role for LSD, particularly for anxiety in cancer patients. In a 1965 Harper’s article, he presented the approach as therapy through self-transcendence, suggesting that a spiritual dimension could have a place in Western medicine. His willingness to consider that possibility coexisted with his attention to abuse and with his criticism of colleagues when he believed they were moving too far from scientific discipline.

That tension became institutional as well as personal. Cohen joined the Commission for the Study of Creative Imagination, established by Al Hubbard in 1955 to pursue psychedelic research beyond medicine’s focus on illness. He resigned abruptly in 1957, after roughly a year on its board. Hubbard’s stated aim reached beyond empirical research toward something he regarded as lying outside its control; Cohen’s departure made visible the growing distance between spiritual or cultural ambitions for psychedelics and the medical project of evaluating treatment.

In May 1966, Cohen and Timothy Leary testified at U.S. Senate hearings, trying to defend legitimate research while distinguishing it from black-market use. Senator Robert F. Kennedy showed sympathy for continued medical investigation and challenged regulators over plans to cancel research projects, but the effort did not prevent the retreat. In October, the FDA ordered researchers across the country to stop their work. Cohen’s testimony belonged to a moment when his long-standing distinction between controlled treatment and uncontrolled use was becoming increasingly difficult to maintain in public policy.

The first wave’s unresolved questions returned at a 1979 reunion at Janiger’s home in Los Angeles. Cohen asked what the work had meant and answered that it had unsettled people’s frames of reference, perhaps on a vast scale. He also offered a generous account of the different roles within the movement: figures such as Leary and Hubbard pushed outward, while people such as Humphry Osmond reflected and studied. The answer did not erase disagreement or turn the past into a success story. It expressed Cohen’s characteristic insistence that research, exploration, and caution could serve different purposes—and that understanding the psychedelic project required making room for all three.