Mental illness is the leading cause of global disability, accounting for one-third of disability worldwide, according to 2008 data from the World Health Organization. In the United States, costs of mental illness are 7 percent of total health care expenditures, with the indirect costs substantially higher at 2 percent of U.S. GDP. Over a lifetime, 50 percent of the population will suffer from at least one psychiatric disorder, and each year, nearly 30 percent of adults have a diagnosable psychiatric disorder. Of patients treated, only 32.7 percent receive minimally adequate treatment, the greatest likelihood of receiving it being highest in the mental health service sector and lowest in the general medical sector, which treats the majority of psychiatric patients. Most U.S. psychiatric patients remain untreated or poorly treated.