Despite international variation in prevalence rates of bipolar spectrum disorder, the severity and associated disorders are similar and treatment needs are often unmet, especially in low-income countries, according to a report in the March issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

"Bipolar disorder (BP) is responsible for the loss of more disability-adjusted life-years than all forms of cancer or major neurologic conditions such as epilepsy and Alzheimer disease, primarily because of its early onset and chronicity across the life span," the authors write as background information in the article. "Few prior international studies of BP have included information on severity or disability associated with this condition."

Kathleen R. Merikangas, Ph.D., of the National Institute of Mental Health, Genetic Epidemiology Research Branch, Bethesda, Md., and colleagues conducted cross-sectional, face-to-face, household surveys to describe the prevalence, symptom severity, patterns of co-existing illnesses, and patterns of service utilization for bipolar spectrum disorder (BPS) in the World Health Organization World Mental Health Survey Initiative. Surveys of 61,392 community adults were carried out in the United States, Mexico, Brazil, Colombia, Bulgaria, Romania, China, India, Japan, Lebanon, and New Zealand.

"In a combined sample of 61,392 adults from 11 countries, the total lifetime prevalences were 0.6 percent for BP-I, 0.4 percent for BP-II, and 1.4 percent for sub-threshold BP, yielding a total BPS prevalence estimate of 2.4 percent worldwide," the authors report.

The severity of symptoms was greater for depressive than manic episodes. Approximately 74.0 percent of respondents with depression and 50.9 percent of respondents with mania reported severe role impairment.

Three-quarters of those with BPS also met criteria for at least one other disorder. Anxiety disorders, especially panic attacks, were the most common comorbid condition.

The surveys found that treatment needs for BPS are often unmet. "Less than half of those with lifetime BPS received mental health treatment, particularly in low-income countries, where only 25.2 percent reported contact with the mental health system," the authors write.

The authors believe their findings document the magnitude and major impact of BP worldwide and underscore the urgent need for increased recognition and treatment facilitation.