John Frederick Joseph Cade (1912-1980), medical scientist, was born on 18 January 1912 at Horsham, Victoria, son of David Duncan Cade, medical practitioner, and his wife Ellen, née Edwards, both Victorian born. David commanded the 3rd Field Ambulance, Australian Imperial Force, during World War I and was awarded the Distinguished Service Order. In 1932 he became medical superintendent at Sunbury Mental Hospital.
Educated at Scotch College and the University of Melbourne (M.B., B.S., 1934; M.D., 1938), John was a resident medical officer at St Vincent's Hospital in 1935 and at the Royal Children's Hospital in 1936. That year he joined the mental hygiene branch of the Department of the Chief Secretary and was appointed medical officer at Mont Park Mental Hospital. At St Patrick's Catholic Cathedral, Melbourne, on 1 November 1937 he married Estana Evelyn Jean Charles, a double-certificated nurse; they were to have four sons and a daughter.
Having served in the Militia from 1935, Cade was appointed captain, Australian Army Medical Corps, A.I.F., on 1 July 1940 and posted to the 2nd/9th Field Ambulance. He arrived in Singapore in February 1941 and was promoted major in September. From February 1942 to September 1945 he suffered the privations of a prisoner of war in Changi camp.
Demobilized on 2 January 1946, Cade returned to the mental hygiene branch, now in the Department of Health, becoming medical superintendent and psychiatrist at the Repatriation Mental Hospital, Bundoora. Suspecting that some excessive toxin in the urine of manic patients was a product of metabolic disorder, he experimented on guinea-pigs with a disused hospital kitchen as his laboratory. He found that the animals became extremely lethargic and were protected from the toxicity of injected urea when lithium carbonate was given simultaneously. Taking lithium himself with no ill effect, he then used it to treat ten patients with chronic or recurrent mania, on whom he found it to have a pronounced calming effect. Cade's remarkably successful results were detailed in his paper, 'Lithium salts in the treatment of psychotic excitement', published in the Medical Journal of Australia (1949). He subsequently found that lithium was also of some value in assisting depressives. His discovery of the efficacy of a cheap, naturally occurring and widely available element in dealing with manic-depressive disorders provided an alternative to the existing therapies of shock treatment or prolonged hospitalization.
In 1952 Cade was appointed psychiatrist superintendent and dean of the clinical school at Royal Park Psychiatric Hospital. Two years later, at the request of the Mental Hygiene Authority which was planning to remodel Royal Park, he visited Britain for six months to inspect psychiatric institutions. On his return, he introduced modern facilities and replaced the rather authoritarian approach to patient care with a more personal and informal style that included group therapy. Concerned at the number of alcohol-related cases, he supported voluntary admission to aid early detection and later proposed the use of large doses of thiamin in the treatment of alcoholism.
Active in professional organizations, Cade was a foundation fellow (1963), State chairman (1963-80) and national president (1969-70) of the (Royal) Australian and New Zealand College of Psychiatrists, and a member (1970-80) of the Medical Board of Victoria. In 1977 he retired from his hospital appointments.
Although the use of lithium revolutionized the treatment of manic-depressive disorders from the 1960s, it was not until 1970 that Cade gained international recognition for his work. That year he received the psychiatric award of the Taylor Manor Hospital, Maryland, United States of America, and was made a distinguished fellow of the American Psychiatric Association. In 1974 he shared the second international award of the Kittay Scientific Foundation in New York with the Danish professor Mogens Schou, whose large clinical trials had validated Cade's research. Appointed A.O. in 1976, Cade was guest of honour that year at an international lithium conference held at New York University's school of medicine.
An 'honourable, upright Christian gentleman', Cade had a mordant sense of humour and an unassuming, rather withdrawn manner. He was modest about his discovery: in his book, Mending the Mind (1979), he discussed the use of lithium treatment without mentioning his own part in it. Survived by his wife and sons, he died of cancer on 16 November 1980 at Fitzroy and was buried in Yan Yean cemetery. A portrait by Max Middleton is held by the family.
Recognition of Cade's pioneering work continued after his death. In 1980 the first John Cade memorial lecture was delivered by Professor Schou at the congress in Jerusalem of the Collegian International Psychopharmacologium (of which Cade had been made an honorary member earlier that year). The John Cade award was inaugurated in 1982 by the Victorian branch of the R.A.N.Z.C.P. and in 1983 the faculty of medicine at the University of Melbourne established the John Cade memorial prize. In 1985 the American National Institute of Mental Health estimated that Cade's discovery of the efficacy of lithium in the treatment of manic depression had saved the world at least $US 17.5 billion in medical costs.