Bipolar disorder , also known as manic depression, is a mental disorder that causes periods of depression and periods of elevated mood. The elevated mood is known as mania or hypomania, depending on its severity, or the symptoms. It causes serious shifts in mood, thinking, energy and behaviour. It shifts from the highs of mania on one extreme, to the lows of depression on the other. The cycles of bipolar disorder last for days, weeks, or months. Unlike normal mood swings, the mood changes of bipolar disorder are so deep that they affect your ability to function. During a manic experience, a person might rashly quit a job or feel revitalized after sleeping two hours. During a depressive period, a same person might be too tired to get out of bed and full of self-loathing and hopelessness over being unemployed and in debt. Cause of Bipolar Disorder External environmental and psychological factors are partly believed to be involved in the development of bipolar dis