The Insulin Coma Therapy Mystery

Medically Reviewed by Melinda Ratini, MS, DO on July 12, 2023
5 min read

In the 1950s and 1960s, a patient diagnosed with schizophrenia would often be admitted to a specialized wing of a hospital called the insulin wing. There, almost every day over the next weeks or months, they would find themselves strapped to a bed and injected with enough insulin to place them into a coma. The procedure often caused convulsions violent enough to cause bitten tongues and broken bones. Sometimes it was fatal.

“The insulin mortality rate could be as high as 5 percent,” says Joel Braslow, MD, PhD, a professor of psychiatry and behavioral sciences at UCLA. “It lends itself to those ‘why did we do that’ questions.”

The most famous case of insulin coma therapy was that of John Nash, one of the world’s most innovative mathematicians, winner of the Nobel Prize, and life-long schizophrenic whose story was the basis of the book and film A Beautiful Mind. Nash’s illness was marked by hallucinations and delusions. Among his many fantasies, he believed for years that he was being persecuted by a cabal of Soviet agents. In 1961, Nash was committed to Trenton Psychiatric hospital in New Jersey, where he received insulin coma therapy for 6 weeks. Nash later described his treatments as “torture.”

Schizophrenia is a severe mental illness that today affects about 22 million people worldwide. It is characterized by an inability to accurately perceive reality, among many other mental symptoms, including depression. It is diagnosable only through observation. Today the symptoms are usually treated with antipsychotic drugs to make them less intense. But the illness itself has always been notoriously difficult to treat.

Even though insulin coma therapy is now known to have no real therapeutic value, by the midpoint of the 20th century, it had become one of the most common treatments. It was not uncommon for mental hospitals like Trenton to have a whole wing devoted to it.

First-hand accounts of the treatment are hard to come by, largely because one of its side effects was loss of memory. But one former patient at Trenton recalled “the sickness, the taste of blood in my mouth … the foggy pain in my head … very little of it is clear in retrospect save the agony of emerging from shock every day.” Nash blamed insulin coma therapy for large gaps in his memory, as did the singer-songwriter Townes Van Zandt, who received the treatment as a teenager at a University of Texas medical center at Galveston.

“It seems likely there may have been some brain damage from these procedures,” says Joanna Moncrieff, MD, a professor of critical and social psychiatry at University College London. “Some early theories were that it worked because it induces brain damage, but in areas that were inactive. Looking back on it, it’s shocking to believe that people believed it was a sensible thing to do.”

Insulin coma therapy was pioneered by a Viennese doctor named Manfred Sakel, who began his career using insulin to treat people addicted to morphine. He later told a colleague he made the discovery when he accidentally put one of his patients into a coma and miraculously cured the man’s schizophrenia. Sakel – who had a somewhat dubious reputation – claimed his procedure had an astonishing 88% success rate.

The therapy took off. By 1960, a nursing journal article called it “a time-honored treatment … widely considered by many to be the most effective therapy in schizophrenia.” The article nonetheless went on to note potentially fatal risks from “prolonged or irreversible coma … pulmonary complications and cardiovascular disturbance.” There were so many, the author said, that it “is not possible in this short article to discuss all the complications fully.”

Yet despite the drawbacks and the emergence of studies showing the therapy had no real medical value, as late as 1969, one leading textbook of psychiatry lauded insulin coma therapy as “a landmark in psychiatric progress.” 

So why did faith in the procedure persist as long as it did? And why did so many early studies show the therapy to be effective? Part of the answer lies in the state of psychiatry at the midpoint of the 20th century. Crowded mental hospitals were chronically understaffed. And there were virtually no medical treatments that offered any promise of curing the severely mentally ill. “It was a hopeless environment,” says Deborah Doroshow, MD, PhD, an assistant professor of medicine at the Icahn School of Medicine and an adjunct assistant professor of the history of medicine at Yale University School of Medicine. “This was not a great era for American psychiatry.” 

Doroshow has interviewed doctors who once used insulin shock therapy. She says they universally felt looked down upon by the rest of the medical profession, working in a field they described as “depressing and quite futile.” Doctors were desperate for actual therapies. Until the 1930s at Trenton Psychiatric Hospital, where Nash was committed, a former superintendent named Henry Cotton routinely had surgeons remove teeth, ovaries, fallopian tubes, uteruses, thyroid glands, and spleens from schizophrenic patients in the belief that infections in these body parts were causing mental illness. Insulin coma therapy seemed to offer real hope. And that hope was reflected in the rosy early studies that relied on doctor observations of “improved” or “better” to gauge success.

But there was another very powerful reason that so many doctors came to embrace insulin coma therapy: The patients did indeed do better. At least they seemed to. This was later shown to be the result of the superior treatment the insulin ward patients received more generally. As Robert Garber, a staff psychiatrist at Trenton who went on to become president of the American Psychiatric Association, put it in the Nash biography A Beautiful Mind: “The insulin unit was the most elite unit in Trenton State Hospital. … It had the best doctors, the best nurses, the nicest furnishings. Only patients who were young and in good health went there. Patients on the insulin unit had special diets, special treatment, special recreation … all the best of what the hospital had to offer was showered on them.”

The illusion of success was finally shattered with the emergence of randomized controlled trials, where factors such as care and patient selection were accounted for. “It was like the emperor has no clothes,” says Doroshow. “The first RCT trials showed insulin coma therapy was no better than doing nothing.”

Yet as crazy as the one-time embrace of insulin coma therapy seems now, UCLA’s Braslow says we should look to our own treatment of the mentally ill before we judge the doctors of the past too harshly. “Even in the 1930s during the Great Depression, we were willing to put huge amounts of resources into insulin coma therapy,” he says. “Today, we just abandon those people to the streets or the jails.”