National Survey on Drug Use and Health Adults with Co-Occurring Serious Mental Illness and a Substance Use Disorder
June 23, 2004

Adults with Co-Occurring Serious Mental Illness and a Substance Use Disorder

In Brief

  • In 2002, more than half of adults with co-occurring serious mental illness (SMI) and a substance use disorder (a total of 2 million adults) received neither specialty substance use treatment nor mental health treatment during the past year

  • Among adults with co-occurring SMI and a substance use disorder, women were more likely to receive mental health treatment in the past year than men

  • The rate of perceived unmet need for mental health treat-ment was higher than the rate of perceived unmet need for substance use treatment among adults with co-occurring SMI and a substance use disorder
    •

The National Survey on Drug Use and Health (NSDUH) includes questions for adults aged 18 or older to assess serious mental illness (SMI) during the year prior to the survey interview. SMI is defined for this report as having had at some time during the past year a diagnosable mental, behavioral, or emotional disorder that met criteria specified in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV),1 and resulted in functional impairment that substantially interfered with or limited one or more major life activities. NSDUH measures SMI using the K-6 distress questions.2,3 NSDUH also includes a series of questions to assess dependence on or abuse of alcohol or an illicit drug. Illicit drugs include marijuana/hashish, cocaine (including crack), inhalants, hallucinogens, heroin, or prescription-type drugs used nonmedically. These questions are designed to measure dependence and abuse based on criteria specified in the DSM-IV. For the purpose of this report, individuals with either alcohol or drug dependence or abuse are said to have a substance use disorder, and individuals with both SMI and a substance use disorder are said to have co-occurring SMI and a substance use disorder.4

NSDUH respondents also were asked about their experiences with mental health or specialty substance use treatment during the past year. Mental health treatment is defined as the receipt of treatment or counseling for any problem with emotions, "nerves", or mental health in the 12 months prior to the interview in any inpatient or outpatient setting; it also includes the use of prescription medication for treatment of a mental or emotional condition.5 Specialty substance use treatment is defined as treatment received at alcohol or drug rehabilitation facilities (inpatient or outpatient), hospitals (inpatient only), or mental health centers.6

Prevalence of Co-Occurring Disorders

In 2002, 17.5 million adults aged 18 or older were estimated to have SMI in the past year. This represents about 8 percent of all adults. About 23 percent (4 million) of adults with SMI in 2002 also were dependent on or abused alcohol or an illicit drug (had co-occurring SMI and a substance use disorder). Among adults without SMI, the rate of dependence or abuse was only about 8 percent (Figure 1).

More than half of adults (a total of 2 million persons) with co-occurring SMI and a substance use disorder received neither mental health nor specialty substance use treatment during the past year (Figure 2). Among adults with co-occurring disorders, 34 percent received mental health treatment only, 2 percent received specialty substance use treatment only, and 12 percent received both mental health and specialty substance use treatment during the past year.

Figure 1. Percentages with Substance Dependence or Abuse in the Past Year, among Adults Aged 18 or Older, by Past Year SMI: 2002

Figure 2. Receipt of Mental Health or Substance Use Treatment in the Past Year among Adults Aged 18 or Older with Co-Occurring SMI and a Substance Use Disorder: 2002
Figure 1. Percentages with Substance Dependence or Abuse in the Past Year, among Adults Aged 18 or Older, by Past Year SMI: 2002 Figure 2. Receipt of Mental Health or Substance Use Treatment in the Past Year among Adults Aged 18 or Older with Co-Occurring SMI and a Substance Use Disorder: 2002
Receipt of Mental Health Treatment

Among adults with co-occurring SMI and a substance use disorder, the following persons were more likely to have received mental health treatment during the past year: females were more likely than males (54 vs. 39 percent, Figure 3) and adults aged 26 to 49 were more likely than young adults aged 18 to 25 (53 vs. 36 percent). 7 The rate of mental health treatment received during the past year among adults with co-occurring disorders was similar in metropolitan counties (47 percent) and in non-metropolitan counties (44 percent).

Receipt of Specialty Substance Use Treatment

Among adults with co-occurring SMI and a substance use disorder, the rate of specialty substance use treatment received during the past year was similar among males (16 percent) and females (11 percent). Adults aged 26 to 49 with co-occurring disorders were more likely to have received specialty substance use treatment during the past year than those aged 18 to 25 (18 vs. 6 percent). The rate of specialty substance use treatment during the past year among adults with co-occurring disorders was higher in metropolitan counties than in non-metropolitan counties (15 vs. 8 percent).

Figure 3. Percentages Who Received Mental Health Treatment in the Past Year among Adults Aged 18 or Older with Co-Occurring SMI and a Substance Use Disorder, by Gender: 2002

Figure 4. Perceived Unmet Need for Past Year Mental Health and Substance Use Treatment among Untreated Adults Aged 18 or Older with Co-Occurring SMI and a Substance Use Disorder: 2002
Figure 3. Percentages Who Received Mental Health Treatment in the Past Year among Adults Aged 18 or Older with Co-Occurring SMI and a Substance Use Disorder, by Gender: 2002 Figure 4. Perceived Unmet Need for Past Year Mental Health and Substance Use Treatment among Untreated Adults Aged 18 or Older with Co-Occurring SMI and a Substance Use Disorder: 2002

Perceived Unmet Treatment Need

In 2002, among the 2 million adults with co-occurring SMI and a substance use disorder who had not received treatment, 24 percent perceived an unmet need for mental health treatment in the past year, only 6 percent perceived an unmet need for specialty substance use treatment in the past year, and only 9 percent perceived an unmet need for both specialty substance use treatment and mental health treatment in the past year (Figure 4). About 61 percent of adults with co-occurring SMI and a substance use disorder who had not received treatment perceived no unmet need for either specialty substance use treatment or mental health treatment in the past year.

End Notes
  1. American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.

  2. Kessler, R. C., Barker, P. R., Colpe, L. J., Epstein, J. F., Gfroerer, J. C., Hiripi, E., Howes, M. J., Normand, S. L., Manderscheid, R. W., Walters, E. E., & Zaslavsky, A. M. (2003). Screening for serious mental illness in the general population. Archives of General Psychiatry, 60, 184–189.

  3. A discussion of the methodology used to generate SMI estimates can be found in Appendix B of the following document: Office of Applied Studies. (2003). Results from the 2002 National Survey on Drug Use and Health: National findings (DHHS Publication No. SMA 03–3836, NHSDA Series H–22). Rockville, MD: Substance Abuse and Mental Health Services Administration. [Available at http://www.oas.samhsa.gov/p0000016.htm#Standard]

  4. Substance Abuse and Mental Health Services Administration. (2002). Report to Congress on the prevention and treatment of co-occurring substance abuse disorders and mental disorders. Rockville, MD: U.S. Department of Health and Human Services.   Available at  http://alt.samhsa.gov/reports/congress2002

  5. Treatment for only a substance abuse problem is not included.

  6. Specialty substance use treatment excludes treatment in an emergency room, private doctor's office, self-help group, prison or jail, or hospital as an outpatient. An individual who was dependent on or had abused an illicit drug is defined as receiving specialty treatment only if he or she reported receiving specialty treatment in the past year for drugs. Similarly, an individual who was dependent on or had abused alcohol was counted as receiving specialty treatment only if he or she received specialty treatment in the past year for alcohol. Individuals who reported receiving specialty substance use treatment but were missing information on whether the treatment was specifically for alcohol or illicit drugs were not counted in estimates of specialty substance use treatment.

  7. Estimates for adults aged 50 or older with co-occurring disorders are not shown due to low precision.
Figure Note

Source: SAMHSA 2002 NSDUH
The National Survey on Drug Use and Health (NSDUH) is an annual survey sponsored by the Substance Abuse and Mental Health Services Administration (SAMHSA). Prior to 2002, this survey was called the National Household Survey on Drug Abuse (NHSDA). The 2002 data are based on information obtained from 68,126 persons aged 12 or older, including 44,481 persons aged 18 or older. 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 NSDUH Report is prepared by the Office of Applied Studies (OAS), SAMHSA, and by RTI International in Research Triangle Park, North Carolina (RTI International is a trade name of Research Triangle Institute).

Information and data for this issue are based on the following publications and statistics:

Office of Applied Studies. (2003). Results from the 2002 National Survey on Drug Use and Health: Summary of national findings (DHHS Publication No. SMA 03–3836, NSDUH series H–22). Rockville, MD: Substance Abuse and Mental Health Services Administration.

Also available online: http://www.oas.samhsa.gov.

Because of improvements and modifications to the 2002 NSDUH, estimates from the 2002 survey should not be compared with estimates from the 2001 or earlier versions of the survey to examine changes over time.
The NSDUH Report (formerly 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 report or other reports from the Office of Applied Studies are available on-line: http://www.oas.samhsa.gov. Citation of the source is appreciated.

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