Less than half of the 4 million adults estimated to have serious mental
illness and a co-occurring substance use disorder in 2002 received treatment
for either problem, according to a June report from the Substance Abuse and
Mental Health Services Administration (SAMHSA).
The data, which come from the 2002 National Survey on Drug Use and Health,
a household survey of 44,481 randomly selected adults in the United States,
found that an estimated 17.5 million adults aged 18 or older had a serious
mental illness during the preceding year, or about 8 percent of all adults in
Furthermore, about 4 million, or 23 percent, of adults with mental illness
in 2002 were also dependent on or had abused illicit drugs and/or alcohol.
In contrast, among adults without a serious mental illness, only about 8
percent acknowledged dependence on or abuse of drugs or alcohol.
The researchers defined serious mental illness as a "diagnosable
mental, behavioral, or emotional disorder that met DSM-IV criteria
during the previous year that resulted in functional impairment that
substantially interfered with one or more major life activities." (They
separated substance use from other mental disorders for the purposes of this
One striking finding was that a little over half (52 percent) of those with
mental illness and a co-occurring substance use disorder received neither
mental health nor specialty addiction treatment during the year prior to the
These were among the findings on the 4 million adults with co-occurring
Findings from the 2002 National Survey on Drug Use and Health are
posted online at<www.oas.samhsa.gov>.▪