Figure 1. Percentages of Adults Aged 18 or Older with Past Year Serious Mental Illness,** by Age Group: 2001	Figure 2. Percentages of Adults Aged 18 or Older with Past Year Serious Mental Illness,** by Race/Ethnicity: 2001

Prevalence of Serious Mental Illness In 2001, approximately 15 million adults aged 18 or older (7 percent of the U.S. population) were estimated to have an SMI during the past year. The rate of past year SMI was higher among young adults aged 18 to 25 (12 percent) than among adults aged 26 to 49 (8 percent) or 50 or older (5 percent) (Figure 1). Females (9 percent) were more likely than males (6 percent) to have a past year SMI. Rates of past year SMI were higher among American Indians/Alaska Natives (14 percent), and lower among Asians (4 percent), compared with other racial/ethnic groups (Figure 2).

Treatment for Serious Mental Illness Past research has shown that in many cases, SMI symptoms can be ameliorated by mental health treatment or counseling.5 However, the 2001 NHSDA revealed that less than one half (47 percent) of persons with an SMI received treatment or counseling during the past year. Among those with an SMI, adults aged 26 or older were more likely to receive treatment or counseling in the past year than those aged 18 to 25 (Figure 3). Females with an SMI were more likely to receive past year treatment or counseling (52 percent) than males with an SMI (38 percent) and whites with an SMI were more likely to receive past year treatment or counseling than blacks or Hispanics with an SMI (Figure 4).

Serious Mental Illness and Substance Use Results from the NHSDA indicated that adults with an SMI were more likely to smoke cigarettes or use an illicit drug during the past year compared with those without an SMI (Figure 5). The rate of cigarette use during the past year was 50 percent among adults with an SMI and 29 percent among those without an SMI. The rate of past year illicit drug use was more than twice as high among adults with an SMI (27 percent) than it was among adults without an SMI (11 percent). Rates of past year alcohol use were similar among adults with or without an SMI.

Figure 3. Percentages of Adults Aged 18 or Older Reporting Receipt of Past Year Mental Health Treatment* among Those with Past Year Serious Mental Illness**, by Age Group: 2001	Figure 4. Percentages of Adults Aged 18 or Older Reporting Receipt of Past Year Mental Health Treatment/Counseling* among Those with Serious Mental Illness,** by Race/Ethnicity:*** 2001

Figure 5. Percentages of Adults Aged 18 or Older Reporting Past Year Substance Use, by Past Year Serious Mental Illness:** 2001

End Notes National Institute of Mental Health. (2001 January). The numbers count: Mental disorders in America (NIMH Publication No. 01–4584). Retrieved September 25, 2002, from http://www.nimh.nih.gov/publicat/numbers.cfm American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author. Kessler, R.C., Barker, P.R., Colpe, L.J., Epstein, J.F., Gfroerer, J.C., Hiripi, E., Howes, M.J., Normand, S.–L. T., Manderscheid, R.W., Walters, E.E., & Zaslavsky, A.M. (in press). New scales to screen for serious mental illness in the general population. Archives of General Psychiatry. A discussion of the methodology used to generate SMI estimates can be found in Appendix B of the following document: Substance Abuse and Mental Health Services Administration. (2002). Results from the 2001 National Household Survey on Drug Abuse: Volume II. Technical appendices and selected data tables (Office of Applied Studies, DHHS Publication No. SMA 02–3759, NHSDA Series H–18). Rockville, MD. U.S. Department of Health and Human Services. (1999). Mental health: A report of the Surgeon General. Retrieved September 25, 2002, from http://www.surgeongeneral.gov/library/mentalhealth/home.html Figure Notes * Treatment is defined as the receipt of treatment or counseling for any problem with emotions, "nerves," or mental health in the past year in any inpatient or outpatient setting, or use of prescription medication for treatment of a mental or emotional condition. ** Serious mental illness (SMI) is defined as having a diagnosable mental, behavioral, or emotional disorder that met criteria in the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM–IV) and that resulted in functional impairment that substantially interfered with or limited one or more major life activities. *** Small sample sizes prevented analyses of American Indians/Alaska Natives and Asians. **** "Any illicit drug" refers to marijuana/hashish, cocaine (including crack), inhalants, hallucinogens, heroin, or prescription–type drugs used nonmedically. Source (all figures): SAMHSA, 2001 NHSDA.

The National Household Survey on Drug Abuse (NHSDA) is an annual survey sponsored by the Substance Abuse and Mental Health Services Administration (SAMHSA). The 2001 data are based on information obtained from 69,000 persons aged 12 or older each year, including adults aged 18 or older who were asked the SMI questions. The survey collects data by administering questionnaires to a representative sample of the population through face–to–face interviews at their place of residence. The NHSDA Report is prepared by the Office of Applied Studies (OAS), SAMHSA, and by RTI in Research Triangle Park, North Carolina. Information and data for this issue are based on the following publication and statistics: Office of Applied Studies. (2002). Results from the 2001 National Household Survey on Drug Abuse: Volume 1. Summary of national findings (DHHS Publication No. SMA 02–3758. NHSDA Series H–17). Rockville, MD: Substance Abuse and Mental Health Services Administration. Also available on–line: http://www.oas.samhsa.gov Additional tables available upon request.

The NHSDA Report is published periodically by the Office of Applied Studies, Substance Abuse and Mental Health Services Administration (SAMHSA). All material appearing in this report is in the public domain and may be reproduced or copied without permission from SAMHSA. Additional copies of this fact sheet may be downloaded from Other reports from the Office of Applied Studies are also available on-line on the OAS home page: http://www.oas.samhsa.gov

This page was last updated on December 31, 2008.