Bipolar disorder, formerly known as manic-depressive illness, is a biological brain disorder that results in extreme psychological and emotional mood swings. Mood swings associated with bipolar disorder are so severe that, if left untreated, they become an obstacle to living a normal, happy life. Bipolar disorder affects all aspects of a person's life, from family to friendships and work.

While everyone goes through periods of highs and lows, bipolar disorder magnifies and intensifies ups and downs to an extreme. A person suffering from bipolar disorder does not just feel "blue" but utterly hopeless, ineffectual and nonvital. These feelings of intense depression often lead to suicidal thoughts or an obsession with suicide.

The manic or "high" end of bipolar disorder also grossly exaggerates reality. Extreme energy and exuberance, visions of grandiosity, and delusions of being all-powerful are common. Though the person might feel empowered, practical dividends are rare. Ideas race through the mind and focus is limited or impossible. The personality is often uncharacteristically verbose, self-aggrandizing, and sexually aggressive or promiscuous in inappropriate situations and circumstances.

While those close to the sufferer often mistake the lows of bipolar disorder for common depressive episodes, the highs can be alarming. A person in the throes of a manic mood swing can appear psychotic to the point of potentially being misdiagnosed as schizophrenic.

Those suffering from bipolar disorder cycle throughout life from one state to the other. Between the manic and depressive states there is often a period of normality. For some, the manic mood might be less pronounced than the depressive mood.

Time periods for completed cycles also vary. A cycle might take a week or longer, or one might experience many cycles within a single day. This is referred to as rapid-cycling.

Medical experts report that bipolar disorder can occur in any age group. Children of parents with bipolar disorder who develop it themselves tend to rapid-cycle, sometimes making it difficult to diagnose against the backdrop of other childhood behavioral problems. Fortunately, there are many treatment options for bipolar disorder. Mood stabilizing medications, talk therapy and other regimens can make the difference between living life on a roller coaster and regaining the ability to be stable and happy. Treatment is ongoing, as the disorder is not cured but managed.

Though scientists don't yet know what causes bipolar disorder, they do recognize that is it passed down in families. A genetic component is likely part of a larger interplay of various factors, as evidence suggests it is not genetic alone. One twin, for example, might have bipolar disorder, while the other does not.

Millions of people suffer from bipolar disorder. According to the National Institute for Mental Health (NIMH) in the United States, about 1% of the American population is affected. Some famous people that have talked openly about having bipolar disorder are Anna Marie "Patty" Duke, Linda Hamilton, Jean-Claude VanDamme, Kristy McNichol, Dick Cavett and Buzz Aldrin.

Threats or talk of suicide should always be taken seriously. If you or anyone you know suffers from extreme moods or depression, see a doctor without delay.