On July 7, 2011, the Substance Abuse and Mental Health Services Administration's Center for Behavorial Health Statistics and Quality published a report summarizing the sources of payment for mental health treatment for adults as captured by the National Survey of Drug Use and Health. Among the primary findings 34.5 percent of individuals receiving outpatient mental health services reported that most costs were covered by private insurance, while 34.7 percent of individuals receiving inpatient services reported that most costs were covered by public insurance. Additionally, 26.2 percent of individuals receiving outpatient mental health services and 18.8 percent of those receiving inpatient services reported that they or a family member were the primary source of payment. Finally, of those that paid for a portion or whose family paid for a portion of treatment, 2.3 percent of individuals receiving outpatient services contributed over $5,000, while 9.6 percent of individuals receiving inpatient services contributed over $10,000. 

From the report:

For many individuals with mental health problems, their willingness to seek and their success in receiving treatment often depend on their ability to pay, either from their own resources or through private or public insurance coverage. Appropriate treatment may be inaccessible because individuals lack any insurance coverage, or the insurance coverage they have for mental health and substance abuse conditions is inadequate. The Mental Health Parity and Addiction Equity Act (MHPAEA) of 2008 and the Affordable Care Act (ACA) of 2010 have the potential to improve access to mental health and substance abuse services. The MHPAEA is expected to improve coverage for people who have limits or caps on their benefits. The ACA is intended to provide access to insurance coverage, including benefits for mental health and substance abuse conditions, for many persons who are currently uninsured.

Substance Abuse and Mental Health Services Administration. (2011). Sources of payment for mental health treatment for adults.