Bipolar disorder (BPD), an affective mood disorder formerly called manic-depressive illness, is a diagnosis rarely seen in elders. It has components of major depression and sometimes mania or hypomania. Many elders previously diagnosed with schizophrenia in their past are now found to have the elements of BPD. The psychiatric community has become aware that bipolar disorder in elders is much more common than previously thought, and progress is being made in appropriate diagnosis and treatment of this condition.