Malaria fever therapy for non-syphilitic psychiatric disease

Deliberately infecting psychiatric patients with malaria and provoking repeated high fevers was treated as a therapeutic method for schizophrenia, intellectual disability, affective disorders, psychopathic disorders, and other conditions without neurosyphilis.

1 episode

Current understanding

Malaria fever therapy had a distinct historical rationale in neurosyphilis, where high fever could impair Treponema pallidum before effective antibiotics were available. That rationale did not establish malaria as a treatment for schizophrenia or other non-syphilitic psychiatric conditions. Historical outcomes for those extensions were mixed and poorly justified, and modern evidence does not support intentionally inducing Plasmodium vivax infection as a psychiatric treatment. Malaria itself is an acute infectious disease that can produce severe complications. The correction therefore concerns the extension of malariotherapy beyond neurosyphilis, not its historically different use against neurosyphilitic disease.

Consequences and human impact

Vienna's university psychiatric clinic maintained a transmissible Plasmodium vivax strain and deliberately infected psychiatric patients well into the 1960s. Most malaria-therapy cases in the clinic's five focal diagnostic groups were not neurosyphilis. Patients with schizophrenia and other diagnoses were used in a practice that contemporary publications scarcely justified, even after neuroleptics and antidepressants provided noninfectious alternatives.

How the consequences followed

The classic indication of general paresis/neurosyphilis was historically distinct. Before penicillin, malaria-induced fever had a biologically plausible and historically meaningful antisyphilitic role, even though it was hazardous. That use was not equivalent to malaria therapy for schizophrenia.

The archival evidence does not prove that every non-neurosyphilitic patient lacked a sincerely intended therapeutic indication. It does show that the clinic extended malaria therapy across diagnoses despite little detailed contemporary justification and sometimes used patients as carriers to preserve the malaria strain.

609 / 772

malaria-therapy cases in Vienna's five focal diagnostic groups were for diagnoses other than neurosyphilis

158

schizophrenia patients were identified as deliberately infected with P. vivax in the 1951–1969 archive

1968

last recorded malaria-fever treatment at the Vienna psychiatric clinic

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

1951–1968Policy basis

Vienna's university psychiatric clinic deliberately infected large numbers of non-neurosyphilitic patients with malaria well into the 1960s. In the archival sample, 609 of 772 malaria-therapy cases within the five principal diagnostic groups involved diagnoses other than neurosyphilis, including schizophrenia, intellectual disability and affective or psychopathic disorders. A separate infectious-disease reconstruction identified 158 schizophrenia patients who had been inoculated, usually with 4–8 mL of P. vivax-infected blood, and who typically underwent several fever attacks before malaria treatment was given. The clinic's own historical record contains little detailed scientific justification for these nonsyphilitic extensions, and the practice persisted until December 1968.

Institutions

Psychiatric-Neurological University Clinic, Vienna
Vienna General Hospital
University of Vienna medical faculty

Documented consequences

Deliberate infection of psychiatric patients with Plasmodium vivax
Repeated febrile attacks before antimalarial treatment terminated the infection
Use in schizophrenia, intellectual disability, affective and psychopathic diagnoses without the neurosyphilis rationale
Continued exposure to an infectious disease after noninfectious psychiatric treatments had become available
Some patients functioned as continuing carriers of the institutional malaria strain

Institutional machinery

Under Hans Hoff, Vienna's university psychiatric clinic continued malaria fever therapy throughout 1951–1968 and applied it far beyond neurosyphilis. The clinic treated people diagnosed with schizophrenia, intellectual disability, affective disorders, psychopathic disorders and additional conditions by deliberately transmitting P. vivax, usually with infected blood, and waiting through repeated fever paroxysms before administering antimalarial drugs. A modern archival study found 772 malaria-therapy cases within five focal diagnostic groups, of which 609—nearly 79%—were not neurosyphilis. The same study found no detailed contemporary discussion justifying malaria therapy for the four nonsyphilitic diagnostic groups. Vienna maintained a syphilis-free malaria strain specifically because non-neurosyphilitic use was frequent, and the last documented treatment occurred in December 1968.

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
Peer-reviewed archival reconstruction documenting 772 malaria-therapy cases in five focal diagnostic groups, 609 nonsyphilitic cases, the extension to schizophrenia, intellectual disability, affective and psychopathic disorders, absence of detailed contemporary justification for those extensions, maintenance of the malaria strain, and the final recorded use in December 1968.
Clinical and Parasitological Characteristics of Plasmodium vivax Malaria in Malaria-Naïve PatientsAmerican Journal of Tropical Medicine and Hygiene
Modern medical-record analysis identifying 869 iatrogenically infected Vienna patients, including 158 with schizophrenia; documents infected-blood inoculation, typical 4–8 mL doses, repeated fever paroxysms and subsequent antimalarial treatment. It explicitly notes that Vienna continued malaria therapy until the late 1960s after most centers had stopped.
Malaria fever therapy: wide-spread administration in Vienna was an exceptional caseMedical University of Vienna
Official university account of the independent historical commission, confirming unusually broad cross-diagnostic use in Vienna, 772 adult focal cases, 35 child-ward cases, and persistence into the 1960s because clinicians considered their experience with the treatment positive.
Psychiatric effects of malaria and anti-malarial drugs: historical and modern perspectivesMalaria Journal
Peer-reviewed historical review distinguishing the successful neurosyphilis rationale from later extensions to non-syphilitic psychiatric disorders, whose results were mixed and less successful.
Malaria — Fact sheetWorld Health Organization
Current clinical context: malaria is an acute parasitic infection; P. vivax is one of the two human malaria species posing the greatest global threat, and malaria can cause severe illness and death.

Last reviewed: 24/08/2026