CHICAGO -- A new study of 14 countries finds that the United States has the highest rate of mental illnesses, including anxiety disorders and depression.

Researchers from Harvard Medical School in Boston and the World Health Organization found that such illnesses are common and undertreated in many of the countries. The study results appear in Wednesday's issue of the Journal of the American Medical Association.

The countries surveyed from 2001-2003 included Colombia, Mexico, United States, Belgium, France, Germany, Italy, Netherlands, Spain, Ukraine, Lebanon, Nigeria, Japan, and China. Mental illness rates ranged from more than 26 percent of people in the United States to a little over 8 percent of people in Italy.

For the study, interviewers who were not psychiatrists spent about two hours asking more than 60,000 adults questions from a mental health survey.

The most common ailments in most countries were anxiety disorders, which include panic attacks, phobias and post-traumatic stress disorder.

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