More Than 4 Percent Of Us Adults Have Bipolar Disorder

Approximately 4.4 percent of U.S. adults may have some form of bipolar disorder during some point in their lifetime, including about 2.4 percent with a "sub-threshold" condition, as per an article in the recent issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Individuals with bipolar disorder tend to fluctuate between periods of maniaan inappropriately elevated mood, characterized by impulsive behavior and an increased activity leveland periods of depression. They are at increased risk of suicide and other medical problems, such as cardiovascular disease, as per background information in the article. Previously, scientists estimated that about 1 percent of adults had bipolar disorder. But evidence indicates that current diagnostic criteria may be too narrow to effectively detect bipolar disorder in the general population, and that a broader definition of bipolar spectrum disorder would identify a number of more individuals with bipolar symptoms, the authors note.

Kathleen R. Merikangas, Ph.D., National Institute of Mental Health, Bethesda, Md., and his colleagues estimated the national prevalence of bipolar disorder using data from 9,282 individuals chosen to represent the general population. The scientists conducted interviews between February 2001 and April 2003 to assess the presence of bipolar disorder and other psychiatric conditions. Participants were classified as having bipolar disorder I, characterized by at least one episode of mania and one of depression; bipolar disorder II, requiring an episode of depression plus hypomania, a milder form of mania that does not require hospitalization; and a milder, sub-threshold bipolar disorder that involves hypomania with or without depression, otherwise classified as bipolar disorder "not otherwise specified" in the current diagnostic nomenclature of the American Psychiatric Association.

The study observed that:

• A total of 1.0 percent of participants had bipolar disorder I and 1.1 percent had bipolar disorder II in their lifetimes; in the prior 12 months, 0.6 percent had bipolar disorder I, 0.8 percent bipolar disorder II and 1.4 percent sub-threshold manifestations of bipolar disorder.
  
• Symptoms began at age 18.2 years for bipolar disorder I, 20.3 years for bipolar disorder II and 22.2 years for sub-threshold bipolar disorder.
  
• 95.8 to 97.7 percent of those with bipolar disorder and 88.4 percent of those with sub-threshold bipolar disorder also had another psychiatric condition, such as an anxiety disorder or substance use disorder, which is a frequent complication of bipolar illness.
  
• The majority of those with lifetime bipolar disorder (80.1 percent) received therapy, including 69.3 percent of those with sub-threshold bipolar disorder; most of those people sought therapy for the depression rather than for the manic symptoms of bipolar disorder.
  
• However, over the prior 12 months, only 25 percent of those with bipolar disorder I, 15.4 percent with bipolar disorder II and 8.1 percent with sub-threshold bipolar disorder received appropriate medication.
  

"The present results reinforce the argument of other scientists that clinically significant sub-threshold bipolar disorder is as least as common as threshold bipolar disorder," the authors write. "Eventhough most individuals with bipolar disorder receive therapy owing to co-morbid disorders, the lack of recognition of their underlying bipolarity leads to only a few receiving appropriate therapy." The findings suggest that a substantial proportion of those diagnosed with major depression may actually have a form of bipolar disorder.

More individuals with other psychiatric disorders should also be screened for bipolar disorder, the authors conclude. "Additional research is needed to resolve uncertainty regarding the most appropriate threshold and boundary distinctions for bipolar disorder. This uncertainty remains a major impediment to advancing the understanding of the bipolar disorder spectrum in the population."


Posted by: JoAnn    Source