SAM-e (S-adenosylmethionine) is found in most living cells. It is thought to be necessary for carrying out a number of important intracellular chemical reactions. SAM-e has been used in Europe for more than twenty years as a treatment for depression. A number of studies have shown it to be equally effective when compared to prescription antidepressants. Most notable is the virtual lack of side effects. However, it has not been well supported in studies of the treatment of bipolar disorder. Additionally, it is not useful for treating mania and has, in fact, been found to switch people with bipolar depression into states of mania. Doses for the treatment of depression range from 400 to 1600 mg per day, although recent investigations indicate that often higher doses (1200 to 1600 mg per day) may be necessary for effectively reducing depressive symptoms. In general, SAM-e poses risks in treating bipolar disorder (e.g., provoking manic episodes). It is strongly recommended that for bipolar disorder SAM-e be taken only with close observation by your treating prescriber.