Bipolar personality disorder, also known as bipolar disorder, is a mental health condition characterized by extreme mood swings, ranging from manic episodes of high energy and euphoria to depressive episodes of sadness and hopelessness. People with bipolar disorder may also experience periods of normal mood in between these episodes. The exact cause of bipolar disorder is not known, but it is believed to be a combination of genetic, biological, and environmental factors. Treatment usually involves a combination of medication and therapy to help manage symptoms and improve quality of life.