News Release

SAMHSA Press Releases

 Date: July 29, 2004
Media Contact: SAMHSA Press
Phone: 301-443-8956



New Study Shows Approximately 4 Million Living with Co-Occurring Serious Mental Illness and Substance Abuse


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), according to a new report from the Substance Abuse and Mental Health Services Administration (SAMHSA).  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 new report, “Serious Mental Illness and Its Co-Occurrence with Substance Use Disorders”, presents information on the prevalence and treatment of serious mental illness and the association between mental illness and substance use among adults aged 18 or older in 2002.

“The time has come to ensure that all Americans who experience co-occurring mental and substance use disorders have an opportunity for treatment and recovery.”  SAMHSA Administrator Charles Curie said.  Clearly our systems of services must continue to evolve to reflect the growing evidence base that promotes integrated treatment and supportive services.  Both disorders must be addressed as primary illnesses and treated as such.”

The data show that 33.2 million adults aged 18 or 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.

The report also indicates that while 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.

The report shows that adults with serious mental illness were more likely to be either unemployed or not in the labor force (36.4 percent) than were persons without a serious mental illness.  Of the three age groups considered in this report, adults aged 18 to 25 had the highest rate of serious mental illness (13.2 percent), followed by adults aged 26 to 49 (9.5 percent) and adults aged 50 or older (4.9 percent).  Overall, the rate of serious mental illness was almost twice as high among females as it was among males.

The report can be accessed at

SAMHSA is a public health agency within the U.S. Department of Health and Human Services.  The agency is responsible for accountability, capacity and effectiveness of the nation’s substance abuse prevention, addictions treatment and mental health service delivery systems.
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