Bipolar disorder, formerly known as “manic depression,” is a condition marked by the experience of a manic or hypomanic episode. A manic episode is a serious event in which mood is affected for at least one week. Common markers of mania are increased energy, decreased need for sleep, starting many new projects (but not necessarily finishing them), risky behaviors, increased alcohol or substance use, impulsiveness, rapid speech, and racing thoughts.
Some people with bipolar disorder experience hypomanic episodes instead of or in addition to manic episodes. Hypomanic episodes include some but not all of the symptoms of manic episodes and last for at least four days.
Bipolar disorder often, but not always, includes depressive episodes as well. In general, bipolar disorder should be primarily treated by a psychiatrist; the psychiatrist will often work in conjunction with a therapist.