| Lithium was the first metal to appear in the universe.
The metal was discovered in 1817 by a scientist named Johan August Arfwedson. It is the hardest of the alkali metals, but is softer than lead and can be drawn into wire and rolled into sheets. Lithium emits a crimson color under a sufficient flame. It has the body-centered cubic crystal structure. It is stored in oil to prevent its reaction with water vapor, which would yield lithium hydroxide (LiOH) and hydrogen gas (H2). The natural isotopes of lithium are lithium-6 which comprises 7.5 percent of the element, and lithium-7 which comprises 92.5 percent.
I was unaware that LiCl was used as a substitute for table salt. But actually, LiCl is not the form it comes in when used to treat bi-polar disorder. The prescription form of lithium is lithium carbonate or Li2CO3.
Lithium helps mitigate symptoms of manic-depressive syndrome, or bi-polar disorder. It is highly effective in the assuagement of a manic episode and in calming the patient, but the effect can often take as long as several weeks to set in. Lithium is not an antidepressant; it is actually a depressant, in that it prevents mania. Since it prevents manic episodes, it also prevents the depressive episodes which follow.
Lithium, as a drug, has terrible side effects. Slurred speech, lack of coordination, and general cognitive impairment is not uncommon. Some people report "being in a fog" all the time, and generally just feeling "dumber". Weight gain, and thirst is not uncommon. If the level in your bloodstream is high enough, it is toxic, like most things, but the difference between therapeutic and toxic is not as much as one would hope. Dehydration while taking lithium is very dangerous because it will cause the lithium concentration in your blood to rise, which can lead to death. Lithium-level blood tests are recommended at least every three months for those who take it. | 
