Bipolar disorder is a mental condition in which a person has wide or extreme swings in their mood. Periods of feeling sad and depressed may alternate with periods of being very happy and active or being cross or irritable.

Alternative Names
Manic depression; Bipolar affective disorder; Mood disorder - bipolar; Manic depressive disorder
Causes
Bipolar disorder affects men and women equally. It most often starts between ages 15 and 25. The exact cause is not known. But it occurs more often in relatives of people with bipolar disorder.
In most people with bipolar disorder, there is no clear cause for the periods (episodes) of extreme happiness and high activity or energy (mania) or depression and low activity or energy (depression). The following may trigger a manic episode:
- Childbirth
- Medicines such as antidepressants or steroids
- Periods of not being able to sleep (insomnia)
- Recreational drug use