For the first time the U.S. Centers for Disease Control and Prevention (CDC) has tallied the national burden of mental illness, and it is high. CDC findings indicate that half of U.S. adults will develop a mental illness during their lifetime. The CDC report cites figures from a 2009 survey conducted by the Substance Abuse and Mental Health Services Administration, which found that 11 million people, or nearly 4% of the population, experienced a serious mental illness during the past year, defined as a condition that affected the ability to function. The CDC report also documents data on suicide: 8.4 million Americans had suicidal thoughts in the past year, 2.2 million made plans to kill themselves, and 1 million attempted suicide.

Mental Illness Surveillance Among Adults in the United States, which was prepared by the CDC's Public Health Surveillance Program Office, is the first agencywide compilation of data from selected CDC surveillance and information systems that measure the prevalence and effects of mental illness in the U.S. adult population. In addition, the 29-page report notes that, “In 2002 and 2003, mental illness cost the United States an estimated $300 billion annually, which included approximately $193 billion from lost earnings and wages and $24 billion in disability benefits in 2002 and $100 billion in health care expenditures in 2003.”

The report cites research on the associations between mental illness and many chronic diseases, including cardiovascular disease, diabetes, obesity, asthma, epilepsy, and cancer, and emphasizes that mental illness often leads to increased morbidity in these other diseases. In addition, rates for injuries—both intentional (for example, suicide and homicide) and unintentional (for example, motor vehicle accidents)—are two to six times higher among persons with a mental illness than in the overall population, according to studies cited in the report, and mental illness is also known to be associated with use of tobacco products and alcohol abuse.

The associations between mental illness and other chronic diseases that are well-known public health problems underlie the report's recommendation of the need for more accurate and timely information on the epidemiology of mental illness. “Future mental illness surveillance surveys should measure both depression and anxiety disorders and include more detailed questions concerning their impact on quality of life, associated chronic medical conditions, and issues such as family violence, alcohol and substance abuse, and access to and use of health care,” the report concludes.

The CDC report appeared as a supplement to the CDC's September 2, 2011, Morbidity and Mortality Weekly Report. It is available on the CDC Web site at www.cdc.gov/mmwr/pdf/other/su6003.pdf. CDC plans to issue a similar report in 2012 focusing on childhood mental illness.