While it is estimated that nearly 40% of people with serious mental illness receive treatment, only 15.3% receive "minimally adequate treatment." Minimally adequate treatment includes either 1) the appropriate medication for the type of disorder and 4 or more visits with a physician or mental health specialist, or 2) when appropriate, 8 or more visits with a mental health specialist.
On the basis of these findings and 1999 U.S. Census data, it is estimated that more than 8.5 million people with serious mental illness do not receive minimally adequate treatment each year.
Source: Wang, Demler, & Kessler (2002)
Surveys: National Comorbidity Survey, 1990-92