Diseases

A brain disorder that causes unusual shifts in mood, energy, activity levels, and the ability to carry out day-to-day tasks, also known as manic-depressive illness.

Persons most commonly affected: Bipolar disorder most often starts in teenagers and young adults. But it also can occur in children and older adults.
Organ or part of body involved: Brain
Symptoms and indications: People with bipolar disorder experience unusually intense emotional states that occur in distinct periods called \"mood episodes.\" An overly joyful or overexcited state is called a manic episode, and an extremely sad or hopeless state is called a depressive episode. Sometimes, a mood episode includes symptoms of both mania and depression. This is called a mixed state. People with bipolar disorder also may be explosive and irritable during a mood episode.

Extreme changes in energy, activity, sleep, and behavior go along with these changes in mood. It is possible for someone with bipolar disorder to experience a long-lasting period of unstable moods rather than discrete episodes of depression or mania.

A person may be having an episode of bipolar disorder if he or she has a number of manic or depressive symptoms for most of the day, nearly every day, for at least one or two weeks.

Sometimes symptoms are so severe that the person cannot function normally at work, school, or home.
Causes and risk factors: The exact cause of the disorder is unknown. Bipolar disorders seem to be inherited, that is relatives of individuals with bipolar disorders are more at risk of developing the same than the general population.