U.S. spending for mental health and substance abuse treatment, 1991-2001.

Spending for mental health and substance abuse (MHSA) treatment in the United States totaled dollar 104 billion in 2001, representing 7.6 percent of all health care spending. The nominal MHSA annual spending growth rate from 1991 to 2001 was 5.6 percent, almost one percentage point below the growth rate for all health care (6.5 percent). During this period, Medicaid has increased to be the largest payer of mental health care, with prescription drugs the fastest-growing spending component. Private insurance payment for substance abuse actually dropped in real dollars, increasing the public share of substance abuse spending.