4 Million Have Co-Occurring Serious Mental Illness, Substance Abuse

People with co-occurring serious mental illness and substance abuse often do not recognize that they need treatment, according to data from SAMHSA's 2002 National Survey on Drug Use and Health (NSDUH), conducted annually by SAMHSA's Office of Applied Studies. The data show that 61 percent of those with both serious mental illness and a substance use disorder who had not received treatment for either illness perceived no unmet need for treatment.

The data also show that more than half (52 percent) of the 4 million adults age 18 and older with co-occurring serious mental illness and a substance use disorder received neither mental health nor specialty substance use treatment during the past year. An estimated 34 percent only received treatment for mental disorders, 2 percent only received specialty substance abuse treatment, and close to 12 percent received treatment for both mental and substance use disorders.

In 2002, 17.5 million adults (8 percent) age 18 and older were estimated to have serious mental illness. Of these, 4 million (23 percent of adults with serious mental illness) were also dependent on or abused alcohol or an illicit drug. Among adults without serious mental illness, the rate of dependence or abuse was only about 8 percent.

Further analysis of the data showed that adults with a substance use disorder in 2002 were almost three times as likely to have serious mental illness (20.4 percent) as those who did not have a substance use disorder (7.0 percent).

The rate of serious mental illness was 19.0 percent among those with alcohol dependence or abuse, 29.1 percent among those with illicit drug dependence or abuse, and highest among adults who had both drug and alcohol dependence or abuse (30.1 percent).

The data show that 33.2 million adults age 18 and older had a serious mental illness or a substance use disorder in 2002. Of these adults, 40.4 percent (13.4 million) had only a serious mental illness; 47.4 percent (15.7 million) had only a substance use disorder; and 12.2 percent (4.0 million) had both serious mental illness and a substance use disorder.

Although 47.9 percent of adults with both serious mental illness and a substance use disorder received some type of treatment, only 11.8 percent of these adults received both mental health and substance abuse services.

Two recent SAMHSA publications discuss these findings in more detail. Serious Mental Illness and Its Co-Occurrence with Substance Use Disorders, 2002, is a 132-page report based on analysis of the 2002 NSDUH data. Adults with Co-Occurring Serious Mental Illness and a Substance Use Disorder is part of a series of short reports on selected topics published by SAMHSA. To obtain copies, contact the National Clearinghouse for Alcohol and Drug Information at P.O. Box 2345, Rockville, MD 20847-2345. Telephone: 1 (800) 729-6686 (English and Spanish) or 1 (800) 487-4889 (TDD). Electronic versions are available online at www.oas.samhsa.gov.

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