BETHESDA, Md., March 8 (UPI) -- Bipolar disorder affects 2.4 percent of the world's population, with the highest rates of prevalence in the United States and lowest in India, researchers said.
Kathleen R. Merikangas of the National Institute of Mental Health in Bethesda, Md., and colleagues conducted 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 in the World Health Organization World Mental Health Survey Initiative.
Surveys of 61,392 adults were carried out in the United States, Mexico, Brazil, Colombia, Bulgaria, Romania, China, India, Japan, Lebanon, and New Zealand, Merikangas said.
The United States has the highest lifetime rate of bipolar disorder at 4.4 percent, and India the lowest at 0.1 percent, CNN reported.
"Bipolar disorder -- people get manic and then swing to depression -- 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 study authors said in a statement. "Less than half of those with lifetime bi-polar disorder received mental health treatment, particularly in low-income countries, where only 25.2 percent reported contact with the mental health system."
The study was published in the March issue of Archives of General Psychiatry.