Insulin coma therapy as a treatment for schizophrenia

Repeated insulin-induced hypoglycaemic coma was treated as a specific or basic therapy capable of producing remission or cure in schizophrenia.

2 episodes

Current understanding

Controlled comparisons did not establish a specific therapeutic benefit from insulin coma itself in schizophrenia. Apparent improvement in early uncontrolled series could reflect patient selection, the natural course of illness, intensive nursing and social care, concurrent treatments, and other non-specific effects. Deliberately inducing profound hypoglycaemia also carried substantial risks, including convulsions, prolonged coma, neurological injury, and death. The historical correction is therefore not that no patient ever improved during an insulin-coma course, but that the insulin-induced coma was not shown to be the effective antischizophrenic mechanism institutions claimed.

Consequences and human impact

Insulin coma therapy deliberately pushed psychiatric patients into profound hypoglycaemia, often repeatedly over weeks. It spread rapidly from Vienna into psychiatric hospitals internationally and became a highly staffed, institutional treatment for schizophrenia. Vienna continued using it around 1970 even after controlled studies had undermined the claim of a specific therapeutic effect.

How the consequences followed

Insulin coma therapy for schizophrenia was distinct from ordinary insulin treatment for diabetes. Patients were intentionally made severely hypoglycaemic and unconscious, then revived with glucose or, later in Vienna, glucagon.

Its decline had more than one cause. Scientific criticism and controlled trials challenged efficacy, while new antipsychotic drugs were also simpler and cheaper to administer. The disappearance of a treatment does not by itself prove why institutions abandoned it.

965

insulin-treatment cases recorded at Vienna's university psychiatric clinic from 1951–1969, mostly coma therapy

31 hospitals

were using deep insulin coma therapy in England and Wales by 1938

0.5–4.5%

range of mortality estimates reported in contemporary insulin-coma literature

Quantitative figures are highlighted only when the cited evidence supports them. The scale of a related catastrophe is not automatically treated as a death toll caused solely by this belief.

Institutional episode

Austria — Vienna

1935–c.1970Policy basis

Insulin coma therapy was developed in Vienna in the mid-1930s and became an established treatment for schizophrenia at the university psychiatric clinic. Clinicians expected early cases to be curable and prescribed repeated comas as a central treatment. Its use declined after neuroleptics appeared and efficacy was increasingly challenged, but Vienna persisted unusually long: a 2025/26 historical study found 965 insulin-treatment cases between 1951 and 1969, mostly coma therapy, and concluded that insulin coma treatment continued there until about 1970.

Institutions

Psychiatric-Neurological University Clinic, Vienna
University of Vienna / later Medical University of Vienna clinical tradition

Documented consequences

Repeated deliberate induction of profound hypoglycaemia and coma in psychiatric patients
Courses commonly involving dozens of coma inductions over several weeks
Risk of convulsions, prolonged coma, neurological injury and death
Continuation of an invasive treatment after its specific efficacy had become seriously disputed

Institutional machinery

Manfred Sakel developed insulin coma therapy for schizophrenia at Vienna's university psychiatric clinic in the mid-1930s. The treatment became embedded in the clinic's therapeutic practice and survived the arrival of neuroleptic drugs. Under Hans Hoff, Vienna clinicians still described correctly indicated full insulin shock treatment in 1960 as the basic treatment for schizophrenia. A modern review of the clinic's records found 965 insulin-treatment cases from 1951–1969, the great majority involving insulin coma therapy, and records continued into 1968; the historical study places final discontinuation at about 1970.

Sources and what they establish

In the shadow of the “psychopharmacological revolution”: Malaria fever, insulin coma, cardiazol and electroconvulsive therapy at the Vienna Psychiatric University Clinic, 1951–1969Wiener klinische Wochenschrift / Springer Nature
Malaria fever therapy: wide-spread administration in Vienna was an exceptional case — results from the historical commissionMedical University of Vienna
Official university account of the historical commission confirming continued parallel use of insulin coma and other shock/fever therapies at the Vienna clinic during the transition to psychopharmacology.

Institutional episode

England and Wales

1936–c.1960Policy basis

England and Wales rapidly institutionalized insulin coma treatment after the Board of Control investigated the Vienna method in 1936. By 1938 it was established in 31 hospitals and had strong professional support. Criticism intensified in the 1950s, and a 1957 controlled trial found no significant difference between insulin coma and a comparison coma treatment, undermining the claim that insulin itself was a specific treatment for schizophrenia. British use then declined rapidly around the end of the decade.

Institutions

Board of Control for England and Wales
Mental hospitals in England and Wales
Royal Medico-Psychological Association

Documented consequences

Government-supported diffusion of insulin coma units through the mental-hospital system
Repeated invasive treatment of people diagnosed with schizophrenia
High staffing and prolonged hospitalization requirements
Exposure to severe hypoglycaemia, convulsions, neurological complications and mortality risk

Institutional machinery

The Board of Control, which inspected and supervised mental hospitals, sent a medical commissioner to Vienna in 1936 and then published guidance on hypoglycaemic shock treatment. Institutional adoption was rapid: by 1938 deep insulin coma therapy was established in 31 hospitals in England and Wales. Professional psychiatric bodies and leading textbooks continued to support the treatment through the 1940s and 1950s. A 1957 controlled randomized study found no significant benefit from insulin over a non-insulin coma comparison, and the procedure was soon displaced and abandoned in British practice.

Sources and what they establish

Insulin coma therapy in schizophreniaJournal of the Royal Society of Medicine
The Retreat Archive — Insulin Coma TherapyWellcome Collection
Archival catalogue documenting introduction of insulin coma therapy at The Retreat in 1938 after favourable reports at the Medico-Psychological Association's annual meeting.

Last reviewed: 24/08/2026