Lithium’s role in medicine
Lithium is a lightweight metal and the third element in the periodic table, and it has a unique history involving its discovery and subsequent application in medicine. The journey from its initial identification to its therapeutic use in psychiatry spans nearly two centuries, marked by a combination of curiosity, scientific investigation, and clinical observation.
Lithium’s story began in the early 19th century, when Swedish chemist Johan August Arfwedson discovered the element in 1817. While analyzing a mineral sample from the island of Uto in Sweden, Arfwedson identified a previously unknown alkali metal. His mentor, chemist Jöns Jacob Berzelius, named the new substance “lithium,” derived from the Greek word “lithos,” meaning “stone.” This name alluded to the fact that lithium was discovered in a mineral, as opposed to other alkali metals like sodium and potassium, which were found in plant tissues.
Although lithium was difficult to isolate in its pure form, chemists like Sir Humphry Davy and William Thomas Brande managed to obtain the metal by electrolysis of lithium salts in the 1820s. In the following decades, researchers began studying the properties and potential applications of lithium compounds. They found that lithium salts, such as lithium carbonate and lithium chloride, were highly soluble in water and could be used as effective solvents.
In the mid-19th century, lithium salts started to be used for various medical applications, although their effectiveness was still poorly understood. Lithium was employed as a treatment for gout and rheumatism, as it was believed to help dissolve uric acid, the substance responsible for these ailments. Lithium was also used to treat bladder stones and other urinary disorders.
The application of lithium in psychiatry began in the late 19th century. In 1871, Dr. William Alexander Hammond, an American neurologist, recommended lithium bromide as a treatment for mania, a symptom associated with bipolar disorder. However, this early use of lithium was limited and inconsistent, as it was often overshadowed by other treatments like barbiturates and bromides.
The modern use of lithium in psychiatry can be traced back to Australian psychiatrist Dr. John Cade. In the late 1940s, Cade was researching the possible connection between mania and excess amounts of uric acid in the body. He conducted experiments on guinea pigs, injecting them with lithium urate to induce mania. Surprisingly, he found that lithium alone had a calming effect on the animals.
Cade’s findings prompted him to test lithium’s therapeutic potential in humans. In a groundbreaking study published in 1949, he demonstrated the efficacy of lithium carbonate in treating manic episodes in patients with bipolar disorder. Over the next two decades, lithium’s use in psychiatry expanded, and it became a standard treatment for bipolar disorder, particularly for managing mania and preventing relapse.