What is lithium? What is it prescribed?

An element. Lithium is a very simple compound, it is an element, #3 on the periodic table. It is was really the first psychiatric drug that we had. It is typically prescribed now for bipolar disorder, where patients have depressive and manic (elevated mood) episodes. However, lithium also is a good antidepressant in itself and is often added for major depression, and it has been proven to reduce suicide.
MOOD STABILIZER. Lithium is a mood stabilizer, and it is prescribed for bipolar disorder. It makes the sad phases of bipolar disorder less sad, and it makes the manic phases of bipolar disorder less manic.