Here is information I copied and pasted from the National Institute of Mental Health on Bipolar Disorder:
"Bipolar disorder, also known as manic-depressive illness, is a brain disorder that causes unusual shifts in a person's mood, energy, and ability to function. Different from the normal ups and downs that everyone goes through, the symptoms of bipolar disorder are severe."
"About 5.7 million American adults or about 2.6 percent of the population age 18 and older in any given year,1 have bipolar disorder. Bipolar disorder typically develops in late adolescence or early adulthood. However, some people have their first symptoms during childhood, and some develop them late in life. It is often not recognized as an illness, and people may suffer for years before it is properly diagnosed and treated."
"Bipolar disorder causes dramatic mood swings—from overly "high" and/or irritable to sad and hopeless, and then back again, often with periods of normal mood in between. Severe changes in energy and behavior go along with these changes in mood. The periods of highs and lows are called episodes of mania and depression."
Here is the NIMH website that I got my info from:
http://www.nimh.nih.gov/publicat/bipolar.cfm#bp1Here is another good resource to read about the psychiatric disorder:
http://en.wikipedia.org/wiki/Bipolar_disorderAlso, I live in California, USA so my information is from US sources