Lithium is a chemical element with the symbol Li, and is classified as a metal. It is third in the periodic table, making it the least dense of all solid elements and the lightest metal. It is silvery-white, soft to touch and reacts briskly with water so needs to be stored in oil.

The lithium given to treat psychiatric illnesses is actually in a the form of a salt, usually lithium carbonate or lithium citrate. Lithium is the oldest of all drugs used in psychiatry; most of it is over 13 billion years old.

As the scientific theory stands, most of the lithium present in the universe was created in the first few seconds during the big bang. It is unusual in this regard as the vast majority of elements were formed inside stars billions of years later. There are 2 stable forms of lithium, Li⁶ and Li⁷, with the latter being most abundant on earth. Oddly, there is a cosmological mismatch in the isotope abundance which is troubling astrophysicists the world over. Creationist accounts of the origins of the universe support the primorial status of lithium (Genesis 1:3 "And God said: Let there be Li"). Possibly.

The discovery of lithium is credited to Johan Arfwedson who was analysing petalite ore (itself described by Jose Bonifacio in 1800). At that time, all of the alkali metals described had been discovered in plant matter and lithium was unique in being extracted from a rock. It's origins dictated its name, lithium from the Greek lithos (stone) with a brief sojourn as lithion. Ironically, its ore petalite was named for its leaf like appearance when cut. Lithium it its elemental form was not isolated until 1821 and only produced in sizable quantities in the late 18 hundreds. Commercial production begain the the 1920's.

Lithium is found throughout the world but not naturally in its elemental form. It is mined in various places such as Chile, Argentina and Nevada. The latter should not be confused with Nirvana, who had a different and somewhat debatable sort of success with lithium.

The first medical application of lithium was in the treatment of gout towards the end of the 19th century. Uric acid is more soluble in the presence of lithium, and since gout was associated with high levels of uric acid it seemed like a sensible idea. Gout as a concept was quite flexible and the term "gouty diathesis" was the focus of much discussion. In essence, the process causing gout was thought to affect other bodily systems as well, resulting in numerous manifestations and illnesses. Depression was thought to be in the gouty diathesis and it wasn't long before lithium was used to treat low mood.

Lithium became something of a panacea during the last century as consumption of spring water containing the salt was popularised. Lithia water was recommended by men of some standing for the treatment of numerous conditions. Some now suggest the benefits of lithium were discovered by the ancient Greeks who similarly advocated the taking of alkali waters. Lithia water was latterly used to make lithia beer, including a special Christmas edition. Londonderry lithia water sponsored the first female round to world cyclist, who even changed her name to that of the company! Lithium grease may have helped her more, though lithium carbonate is of little use in rapid cycling.

In 1929, a soft drink trading under the name "bib-labelled lithiated lemon and lime soda" was marketed with some success despite poor timing with the US economic depression. Its more popular name? 7-UP. Lithium was added until the 1950's and it would be fun to imagine people getting high on the original Coca-cola only to come down with the 7-UP. However, Coca-cola finally became cocaine-free in the year 7-UP was introduced.

Lithium salt was used as a substitute for common table salt by patients with cardiac disease on a sodium restricted diet. The consequences of higher doses of lithium became clear and numerous toxic effects were noted in this group of people. The research warning of it's harmful effects in excess were published in the same year as a seminal paper demonstrating its benefits for people suffering from mania.

Lithium has been formally used in psychiatry for over 60 years, with applications as a mood stabiliser in bipolar disorder, an antidepressant booster in depression and in other conditions such as headache. It may find use in progressive conditions such as some types of dementia. Safety is paramount in such treatment regimes, and effective safe blood levels are now well established. Used correctly, lithium can have profound benefits and is the only drug that his been shown to reduce the rate of suicide in those with mood disorders.

Unfortunately, we cannot say exactly how this drug works. There are many theories and a great deal of evidence, but no firm conclusions. What is more, we cannot say with confidence how much of a given dose actually gets into the brain to have these effects.

Team Lithium have developed a scanning technique that allows the concentration of lithium to be measured in the human brain swiftly and harmlessly. We are testing this equipment and applying it to better understand the nature of bipolar disorder and its treatmemts.