Mental Disorders are Disabling

The burden of mental illness on health and productivity in the United States and throughout the world has long been profoundly underestimated. Data developed by the massive Global Burden of Disease study,¹ conducted by the World Health Organization, the World Bank, and Harvard University, reveal that mental illness, including suicide,² ranks second in the burden of disease in established market economies, such as the United States (Table 1-1).
Mental illness emerged from the Global Burden of Disease study as a surprisingly significant contributor to the burden of disease. The measure of calculating disease burden in this study, called Disability Adjusted Life Years (DALYs), allows comparison of the burden

Table 1-1. Disease burden by selected illness categories in established market economies, 1990

	Percent of Total DALYs*
All cardiovascular conditions	18.6
All mental illness**	15.4
All malignant diseases (cancer)	15.0
All respiratory conditions	4.8
All alcohol use	4.7<
All infectious and parasitic diseases	2.8
All drug use	1.5

*Disability-adjusted life year (DALY) is a measure that expresses years of life lost to premature death and years lived with a disability of specified severity and duration (Murray & Lopez, 1996).

**Disease burden associated with“mental illness” includes suicide.

of disease across many different disease conditions. DALYs account for 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, major depression is equivalent in burden to blindness or paraplegia, whereas active psychosis seen in schizophrenia is equal in disability burden to quadriplegia.

By this measure, major depression alone ranked second only to ischemic heart disease in magnitude of disease burden (see Table 1-2 ). Schizophrenia, bipolar disorder, obsessive-compulsive disorder, panic disorder, and post-traumatic stress disorder also contributed significantly to the burden represented by mental illness.

Table 1-2. Leading sources of disease burden in established market economies, 1990

		Total DALYs (millions)	Percent of Total
.	All causes	98.7	.
1	Ischemic heart disease	8.9	9.0
2	Unipolar major depression	6.7	6.8
3	Cardiovascular disease	5.0	5.0
4	Alcohol use	4.7	4.7
5	Road traffic accidents	4.3	4.4

Source: Murray & Lopez, 1996.