Lithium is a soft, silvery metal, so soft that it can be cut with a sharp knife. It is the lightest of all metals and has a density only half that of water. Lithium reacts easily with water and does not occur freely in nature. Lithium carbonate (Li2CO3) has been used since the 1960s for treatment of those who suffer from the psychological disorder of manic depression or bipolar affective disorder.
Lithium's effect on mood stabilization was first discovered by John Frederick Joseph Cade, and was published September 1949 in the Medical Journal of Australia. Cade was testing the effect of uric acid on mice. Because uric acid is insoluble, Cade chose the most soluble salt of it, lithium urate. He discovered that this compound had a calming effect on mice. After extensive testing, he also discovered that while lithium had little effect on depressed patients, manic patients became much calmer after lithium use.
One of the main uses of lithium treatment is in the treatment of those at risk of suicide. There is a strong connection between suicide risk and bipolar disorder. The suicide rate for those with bipolar disorder is approximately 20%. On average, lithium reduces suicide risk by at least sixfold.
"Discontinuation of lithium treatment should occur only if absolutely necessary and even then must be done gradually. All studies show that gradual reduction causes a much lower risk of relapse than abrupt discontinuation. After discontinuation, the risk of suicide jumps to the level it was before treatment began, and for the first six to twelve months, the risk is many times more – roughly twentyfold." [Larson, R. (1998) Lithium Prevents Suicides. Insights on the News, 14 (18), 39]
The required dosage (15-20mg per kg of body weight) is slightly less than the toxic level, requiring blood levels of lithium to be monitored extremely closely during treatment. In order to prescribe the correct dosage, the patient's entire medical history, both physical and psychological, is taken into consideration. Blood tests should be carried out every 3 months to ensure the appropriate level of lithium and thus prevent toxicity, along with kidney and thyroid tests.
Lithium has been the first choice for years for the treatment of bipolar disorder, sold under the names Carbolith, Duralith, Eskalith, Lithane, Lithizine, and Lithobid. Effectiveness is maximized when serum concentrations are maintained at 1.0-1.2 mmol/L. Lithium has long been used to reduce suicide risks.
One of the main reasons that lithium is still used in treatment is its effectiveness in reducing symptoms and frequency of episodes. "The response rate is 70-80% for the initial and maintenance of mania, with a good response defined as fewer, less severe, and shorter manic or hypomanic episodes, although these episodes may continue to occur." [Larson, R. (1998) Lithium Prevents Suicides. Insights on the News, 14 (18), 39]
Lithium carbonate, orotate or aspartate has been found to be effective in treating chronic cluster headaches, possibly due to its ability to impact the electrical system within the brain. The usual dose for the carbonate form is 300mg 2-3 times daily. Lithium levels should be checked and kept within, or even slightly below, the therapeutic range for bipolar disorder, namely 0.5 to 1.5 milliequivalents per liter.