同意。約6%的美國成年人有嚴重精神病。

"An estimated 26.2 percent of Americans ages 18 and older — about one in four adults — suffer from a diagnosable mental disorder in a given year. When applied to the 2004 U.S. Census residential population estimate for ages 18 and older, this figure translates to 57.7 million people.² Even though mental disorders are widespread in the population, the main burden of illness is concentrated in a much smaller proportion — about 6 percent, or 1 in 17 — who suffer from a serious mental illness.¹ In addition, mental disorders are the leading cause of disability in the U.S. and Canada."

http://www.nimh.nih.gov/health/publications/the-numbers-count-mental-disorders-in-america/index.shtml