| Lithium Carbonate (LiCO3) is a compound often used in psychiatric medicine for the treatment of Bipolar Personality Disorder (aka manic depression). While its exact mechanism of action is unknown, Lithium does not have the sedative effect characteristic of most other anti-manic agents.
What is known is that Lithium Carbonate reduces the action of Norepinephrine and Serotonin in the brain, and inhibits the production of Cyclic AMP.
Lithium acts as a mood stabilizer, and is used to treat severe manic episodes. (Editorial aside: Do not take Lithium if you're depressed. Don't.) Lithium should not be given to patients with cardiovascular or renal disease, nor should it ever be used in conjunction with a salt-free diet.
Lithium reaches peak blood serum concentrations 2-4 hours after administration, and has a serum half life of 20-24 hours (longer in patients with impaired renal function). It is usually administered orally, as a pill or capsule. Standard starting dosage is 300 mg twice daily; this is usually increased to an effective dose of 900-1800 mg per day, divided into two or three doses.
The effective dose of Lithium is relatively close to a toxic overdose, so it is important that patients are tested monthly for toxic serum levels. Side effects of Lithium Carbonate include fatigue, thirst, polyuria, and characteristic hand tremors.
I hope I haven't left out anything important. If I have, somebody /msg me and I'll fix things. | 
