"A third type of depressive disorder is bipolar disorder, also called manic-depression. A person who has bipolar disorder alternates between episodes of major depression and mania, periods of abnormally and persistently elevated mood or irritability. During manic periods, the person will also have three or more of the following symptoms: overly inflated self-esteem, decreased need for sleep, increased talkativeness, racing thoughts, distractibility, increased goal-directed activity or physical agitation, and excessive involvement in pleasurable activities that have a high potential for painful consequences. While in a manic phase, adolescents may engage in risky or reckless behaviors such as fast driving and unsafe sex. Bipolar disorder frequently begins during adolescence or young adulthood. Adults with bipolar disorder often have clearly defined episodes of mania and depression, with periods of mania every two to four years."