Mental illness is one of them most disabling conditions in the world but is rarely treated, according to the World Health Organization's (WHO) World Mental Health Survey.

Medical News Today reported Sept. 11 that the survey of 17 countries found that mental illness ranks in the top 10 illnesses causing disability, but few people with mental illness or addictions received adequate care.

Residents of less-developed nations were less likely to seek help for their mental-health problems, the survey found. For example, 18 percent of Americans used mental-health services -- the highest rate in the world -- compared to 1.6 percent in Nigeria.

However, only 18 percent of U.S. residents who sought mental-health care received adequate services, the lowest rate among wealthier nations.

"Although people sought and used services more in the United States, most did not receive adequate care -- evidence of a striking disconnect in the U.S. mental-health care system," said lead researcher Philip S. Wang, M.D., Dr.P.H., currently director of the U.S. National Institute of Mental Health's (NIMH) Division of Services and Intervention Research. "We need to help developing countries implement more effective mental health care services, but we also need to do a better job at home."

"Good treatments are available for many mental disorders. Yet, the world continues to struggle with the very real challenge of providing these services to the people who most need them," added Thomas R. Insel, director of NIMH, which helped fund the survey. "The WHO survey unmistakably reinforces the urgency that we must do better."

The survey results were published in the September 8, 2007 issue of The Lancet.