We all experience a variety of moods such as happiness, sadness, and anger. Unpleasant moods and changes in mood are normal reactions in everyday life, and we can often identify the events that caused our mood to change. However, when we experience extreme mood changes that affect how we behave and function, these changes are often the result of a mood disorder.
Bipolar disorder (formerly known as manic-depressive disorder) is a mood disorder that consists of periods of extremely elevated mood (mania), extremely low mood (depression), and normal mood.
Bipolar disorder typically begins for people during adolescence and early adulthood. It is unusual for bipolar disorder to begin in childhood without strong familial risk factors, and it is rare for its onset to occur after the age of 60 (unless it is associated with another medical condition). Bipolar disorder occurs in about 1% of the adult population, and men and women are affected equally.