Men and women are equally likely to develop the condition, usually between the ages of 15 and 30. However, research has shown that women are more likely than men to develop the rapid cycling form of the condition—with episodes occurring four or more times within a 12-month period. Most often, symptoms begin between age 15 and 30. Research has shown that there is a genetic component to the disorder and that people with a close relative with bipolar disorder are four to six times more likely to develop it than people with no family history.