Bipolar disorder is a mental condition sometimes called manic-depression that involves extreme mood swings. A person with the condition may feel happy and excited at one moment and depressed the next. Mania is characterized by persistent elation, high energy, and sometimes uncontrolled, aggressive behavior. Depression is characterized by persistent sadness, low energy, and sometimes feelings of despairs. Unlike ordinary mood swings, the mood changes of Bipolar Disorder are so intense that they lead to impaired functioning.