Among the more remarkable medical discoveries of the twentieth century, convulsive therapy is an unheralded success. At a time when the only effective treatment for a major psychiatric disorder was fever therapy for neurosyphilis, the reports that the induction of seizures relieved the psychosis of dementia praecox were rapidly and widely accepted. Seizures were first induced by intramuscular injections of camphor by Ladislas Meduna, a Hungarian neuropsychiatrist. Within a year, he described the benefits of intravenous pentylenetetrazol, known commercially as Cardiozol and Metrazol. The benefit of convulsive therapy in patients with mood disorders was quickly recognized, but nowhere is its efficacy more striking than in the relief of melancholia. When and how was this association made?

The first detailed reports on the effects in manic-depressive disorders appeared in 1938: “The facility with which so many diverse reactions were influenced by cardiozol fits led me … to experiment with emotional and conduct disorders of non-schizophrenic type.” Cook described four manic patients whose excitement and psychosis were quickly relieved. An agitated psychotic depressed patient recovered; of three depressed patients with severe psychomotor retardation, two recovered; and a postpartum depressed patient became hypomanic and left the hospital much improved. Simultaneous reports were made by Bennett, who reported relief within two weeks in 21 seriously depressed patients treated with Metrazol-induced seizures and by Küppers (1939), who described the augmentation of insulin coma by Metrazol seizures.