Lithium may be the most well-studied medication in psychiatry. It’s been shown to be effective in the treatment of manic, mixed and depressed states. It is the only mood stabilizer to date that has been demonstrated to substantially decrease the risk (nearly tenfold) that someone with bipolar disorder will commit suicide.
Lithium has also been shown to significantly decrease the severity and frequency of mood episodes. This becomes an important point when discussing maintenance therapy. Certain medications and treatments may be extremely helpful to get an acute manic or depressed state under control, but may not be required once mood stabilization has been achieved. Lithium is typically continued.