Bipolar disorder affects about 2 million people in the United States in any given year. Both men and women are affected at the same rate. There are few risk factors that reliably predict a significant increased likelihood of being diagnosed with bipolar disorder.
Genetics and one’s family history appear to both have some influence over the likelihood of being diagnosed with bipolar disorder. Bipolar disorder is more common in those who have a sibling or parent with the illness and in families having several generations affected with mood disorders.
Differing rates of bipolar disorder have not been reported for different races. Lower socioeconomic status may be slightly linked to a higher rate of bipolar disorder.
The estimated average age for the onset of bipolar disorder is during the early 20s, although there have been reports of the disorder beginning as early as elementary school. In fact, bipolar disorder appears before age 20 in about one in five manic individuals.
Younger patients first may suffer cyclothymia, which is basically a less extreme form of bipolar disorder characterized by hypomanic and mild depressive episodes. Although people with cyclothymia display less intense symptoms, nearly half of them will progress to having a full manic episode. Younger patients who have full manic episodes are called juvenile bipolar patients.