Insulin Coma Therapy — Dozens of Near-Fatal Comas, Beaten by a Sleeping Pill

In 1933 the Austrian psychiatrist Manfred Sakel announced from Vienna that he could break schizophrenia by injecting patients with enough insulin to crash their blood sugar into deep coma — and reported, on uncontrolled case series with no comparison group, recovery rates of 70 to 80 percent; the distance between that claim and what a controlled trial eventually found is the whole of this case. The procedure that resulted held patients in repeated, deliberately induced hypoglycemic comas — typically a course of 20 to 60 sessions, each lasting up to an hour, terminated by glucose — across asylums in Europe and North America for two decades, and killed on the order of one to two patients in every hundred treated, with some series running higher.

Insulin coma therapy (ICT) did not survive on evidence. It survived on enthusiasm and on a flattering selection effect. As the British psychiatrist Harold Bourne argued in his 1953 Lancet paper “The Insulin Myth,” ICT units selected younger, recently-ill, better-prognosis patients, lavished them with intensive nursing in dedicated wards, and then credited insulin for an improvement that the selection and the attention had largely produced. Bourne’s verdict — that insulin patients were “an elite group sharing common privileges and perils,” and that the coma added nothing specific — was a theoretical demolition that the field initially refused to print; the Journal of Mental Science sat on his manuscript for a year and rejected it, telling him to “get more experience.”

The empirical reckoning arrived in 1957, when Brian Ackner, Arthur Harris and A.J. Oldham published in The Lancet one of the first randomized controlled trials in psychiatric history. Fifty schizophrenia patients were randomly allocated either to insulin coma or to an identical regimen in which the unconsciousness was produced by barbiturates instead — same ward, same nursing, same coma, different agent. There was no difference in outcome. Whatever the regimen achieved, insulin was not the active ingredient. Within a few years ICT had collapsed, helped over the edge by chlorpromazine, which by the late 1950s delivered comparable results without driving anyone into a coma. It was never recalled and never banned; it was simply discredited and abandoned, and it is now taught as the first major therapy retired by a randomized controlled trial — and a textbook illustration of how a selection effect can masquerade as a cure.