Suicide, which is both a stereotypic yet highly individualized act, is a common endpoint for many patients with severe psychiatric illness. The mood disorders (depression and bipolar manic-depression) are by far the most common psychiatric conditions associated with suicide. At least 25% to 50% of patients with bipolar disorder also attempt suicide at least once. With the exception of lithium--which is the most demonstrably effective treatment against suicide-remarkably little is known about specific contributions of mood-altering treatments to minimizing mortality rates in persons with major mood disorders in general and bipolar depression in particular. Suicide is usually a manifestation of severe psychiatric distress that is often associated with a diagnosable and treatable form of depression or other mental illness. In a clinical setting, an assessment of suicidal risk must precede any attempt to treat psychiatric illness.