An estimated 5.7 million Americans have bipolar disorder, a serious mental illness that has been characterized by recurrent periods of mania and depression. Because mania, which involves having an elevated or irritable mood, and depression are mood disturbances, bipolar disorder is considered a type of mood disorder.
Results of the report align with earlier research demonstrating that depression and anxiety commonly co-occur, and with twin studies indicating that depression and a common form of anxiety known as generalized anxiety disorder behave virtually as the same genetic condition. The new findings extend the close connection between depression and anxiety to individuals with bipolar disorder who have experienced episodes of mania.
"Although it has long been widely assumed that bipolar disorder represents repeated episodes of mania and depression as poles along a single continuum of mood, the clinical reality is often far more complex," said Mark Olfson, MD, MPH, professor of psychiatry at Columbia University Medical Center, research psychiatrist at New York State Psychiatric Institute, and lead author of the report. "The link between mania and anxiety suggests that patients whose main symptom is anxiety should be carefully assessed for a history of mania before starting treatment."
A broader clinical definition of bipolar disorder that includes episodes of mania along with anxiety or depression might lead to earlier identification of individuals with bipolar disorder and different approaches to treatment.
"For years, we may have missed opportunities to evaluate the effects of treatments for bipolar disorder on anxiety," said Dr. Olfson. "The results of our study suggest that researchers should begin to ask whether, and to what extent, treatments for bipolar disorder relieve anxiety as well as mania and depression."