Formerly known as Manic Depressive Disorder is a chronic, or episodic mental disorder.It can cause extreme fluctuating changes in mood, energy, activity,and concentration. The symptoms often develop in late adolescence and require a lifetime of treatment.During the range of mood changes the person, might feel sad, or hopeless and other times the person might feel happy, or “up”. However, on other occasions, a person may have less severe symptoms known as a hypomanic episode.Doctors treat Bipolar Disorder with a combination of medication and psychotherapy.

Source: www.nimh.nih.gov