The burden of mental illness on health and productivity in the United States and throughout the world has long been underestimated. Data developed by the massive Global Burden of Disease study¹ conducted by the World Health Organization, the World Bank, and Harvard University, reveal that mental illness, including suicide, accounts for over 15% of the burden of disease in established market economies, such as the United States. This is more than the disease burden caused by all cancers.

This Global Burden of Disease study developed a single measure to allow comparison of the burden of disease across many different disease conditions by including both death and disability. This measure was called Disability Adjusted Life Years (DALYs). DALYs measure lost years of healthy life regardless of whether the years were lost to premature death or disability. The disability component of this measure is weighted for severity of the disability. For example, disability caused by major depression was found to be equivalent to blindness or paraplegia whereas active psychosis seen in schizophrenia produces disability equal to quadriplegia.

Using the DALYs measure, major depression ranked second only to ischemic heart disease in magnitude of disease burden in established market economies. Schizophrenia, bipolar disorder, obsessive-compulsive disorder, panic disorder, and post-traumatic stress disorder also contributed significantly to the total burden of illness attributable to mental disorders.

The projections show that with the aging of the world population and the conquest of infectious diseases, psychiatric and neurological conditions could increase their share of the total global disease burden by almost half, from 10.5 percent of the total burden to almost 15 percent in 2020.

Facts

• Depression is the leading cause of disability worldwide among persons age five and older.
• For women throughout the world as well as those in established market economies, depression is the leading cause of DALYs. In established market economies, schizophrenia and bipolar disorder are also among the top ten causes of DALYs for women.

Disease Burden by Selected Illness Categories in Established Market Economies, 1990,

Mental Illness as a Source of Disease Burden in Established Market Economies, 1990,

*DALYs measure lost years of healthy life regardless of whether the years were lost to premature death or disability.

NIH Publication No. 99-4586. Reprinted by permission.