Bipolar disorder, also known as manic depression illness, is an anxiety disorder that causes unusual shifts in a person's mood, energy, and ability to function. Different from the normal ups and downs that everyone goes through, the symptoms of bipolar disorder are severe. They can result in damaged relationships, poor job or school performance, and even suicide. But there is good news: anxiety disorders and bipolar disorder can be treated, and people with this illness can lead full and productive lives.

 More than 2 million American adults, or about 1 percent of the population age 18 and older in any given year, have different forms of anxiety disorders. Bipolar disorder typically develops in late adolescence or early adulthood. However, some people have their first symptoms during childhood, and some develop them late in life. It is often not recognized as an illness, and people may suffer for years before it is properly diagnosed and treated. Like diabetes or heart disease, bipolar disorder is a long-term illness that must be carefully managed throughout a person's life.

 "Manic depression distorts moods and thoughts, incites dreadful behaviors, destroys the basis of rational thought, and too often erodes the desire and will to live. It is an illness that is biological in its origins, yet one that feels psychological in the experience of it; an illness that is unique in conferring advantage and pleasure, yet one that brings in its wake almost unendurable suffering and, not infrequently, suicide. "I am fortunate that I have not died from my illness, fortunate in having received the best medical care available, and fortunate in having the friends, colleagues, and family that I do."

Kay Redfield Jamison, Ph.D., An Unquiet Mind, 1995, p. 6. (Reprinted with permission from Alfred A. Knopf, a division of Random House, Inc.)

What Causes Bipolar Disorder?

Scientists are learning about the possible causes of bipolar disorder through several kinds of studies. Most scientists now agree that there is no single cause for bipolar disorder—rather, many factors act together to produce the illness. Because bipolar disorder tends to run in families, researchers have been searching for specific genes—the microscopic "building blocks" of DNA inside all cells that influence how the body and mind work and grow—passed down through generations that may increase a person's chance of developing the illness. But genes are not the whole story. Studies of identical twins, who share all the same genes, indicate that both genes and other factors play a role in bipolar disorder. If bipolar disorder were caused entirely by genes, then the identical twin of someone with the illness would always develop the illness, and research has shown that this is not the case. But if one twin has bipolar disorder, the other twin is more likely to develop the illness than is another sibling.

 In addition, findings from gene research suggest that bipolar disorder, like other mental illnesses, does not occur because of a single gene. It appears likely that many different genes act together, and in combination with other factors of the person or the person's environment, to cause bipolar disorder. Finding these genes, each of which contributes only a small amount toward the vulnerability to bipolar disorder, has been extremely difficult. But scientists expect that the advanced research tools now being used will lead to these discoveries and to new and better treatments for bipolar disorder.

 Brain-imaging studies are helping scientists learn what goes wrong in the brain to produce bipolar disorder and other mental illnesses. New brain-imaging techniques allow researchers to take pictures of the living brain at work, to examine its structure and activity, without the need for surgery or other invasive procedures. These techniques include magnetic resonance imaging (MRI), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI). There is evidence from imaging studies that the brains of people with bipolar disorder may differ from the brains of healthy individuals. As the differences are more clearly identified and defined through research, scientists will gain a better understanding of the underlying causes of the illness, and eventually may be able to predict which types of treatment will work most effectively.

Source: nimh.nih.gov