Dr. John Cade (18 January 1912 – 16 November 1980) was an Australian psychiatrist credited with discovering (in 1948) the effects of lithium carbonate as a mood stabilizer in the treatment of bipolar disorder (then known as manic depression). In an age where the standard treatments for psychosis were electroconvulsive therapy and lobotomy, lithium had the distinction of being the first effective medication available to treat a mental illness.

It was at an unused kitchen in Bundoora where he conducted crude experiments which led to the discovery of lithium as a treatment of bipolar disorder. These experiments mostly consisted in injecting urine from mentally ill patients into the abdomen of guinea pigs. These would appear to die faster than when healthy persons’ urine was used, leading him to think that perhaps more uric acid was present in the samples provided by his mentally ill patients. Then, in an effort to increase the water solubility of uric acid, lithium urate was added to the solution. Cade found that in the guinea pigs injected with the lithium urate solution, toxicity was greatly reduced. However, his use of careful controls in his experiments revealed that the lithium ion had a calming effect by itself. After ingesting lithium himself to ensure its safety in humans,[1] Cade began a small-scale trial of lithium citrate and/or lithium carbonate on some of his patients diagnosed with mania, dementia præcox or melancholia, with outstanding results. The calming effect was so robust that Cade speculated that mania was caused by a deficiency in lithium.

While Dr. Cade’s results appeared highly promising, side-effects of lithium in some cases lead to non-compliance. Toxicity of lithium led to several deaths of patients undergoing lithium treatment. The problem of toxicity was greatly reduced when suitable tests were developed to measure the lithium level in the blood. Moreover, as a naturally-occurring chemical, lithium salt could not be patented, meaning that its manufacturing and sales were not considered commercially viable. These factors prevented its widespread adoption in psychiatry for some years, particularly in the United States, where its use was banned until 1970.