Bipolar disorder (formerly known as manic depression) is a mental health condition characterized by intense, unpredictable mood swings . If you have bipolar disorder, you will find yourself fluctuating between periods of intense highs (mania) and deep lows (depression).
Types of Bipolar Disorder
There are two main types: Bipolar I (manic depression) is the classic type, with more chaotic manic episodes followed by depressive ones. Bipolar II is more common and the manic episodes are not as intense. People living with bipolar II often function better than those with bipolar I. Some people may experience forms of bipolar disorder that are not the distinct type I or II.
A study  in 2005 found that 2.6 percent of Americans were living with some form of bipolar disorder. Bipolar disorder doesn’t look the same for everyone. The duration of your depressive or manic episodes may last anything from a few hours to a few weeks. Sometimes episodes may go on for months. Some people may experience short swings so widely far apart that they don’t even realize they are bipolar. Others may experience clustered mood swings that happen frequently enough to seriously disrupt their lives.