Between 2001 and 2003, Ronald Kessler, Ph.D., a professor of health care
policy at Harvard Medical School, and colleagues undertook a formidable
challenge—determining the status of Americans' mental health.
Their assessment—called the National Comorbidity Survey
Replication—was based on detailed interviews with more than 9,000
Americans, representative of the American population. The major results from
the survey were published in the June 2005 Archives of General Psychiatry
(Psychiatric News, July 15, 2005).
Now in the April American Journal of Psychiatry, Kessler and his
team reported what they have learned from their survey about adult
attention-deficit/hyperactivity disorder (ADHD). This illness was not
addressed by the last two major American psychiatric epidemiology
surveys—the Epidemiologic Catchment Area Study and the National
Because of concern about recall failure among older adults, Kessler and his
coworkers decided to assess only 3,199 of their survey participants, all
between 18 and 44 years of age, for the presence of adult ADHD. The
assessments were conducted by lay interviewers using the Diagnostic Interview
Schedule for DSM-IV. Respondents who indicated that they had had ADHD
in childhood were then asked an additional question—whether they
continued to have any ADHD symptoms. Of the 3,199 participants, 3 percent were
found to have had childhood ADHD as well as current ADHD symptoms.
Then 154 of the 3,199 participants—representing an oversampling of
those with adult ADHD symptoms—were assessed in reappraisal interviews
for adult ADHD. These interviews were conducted by clinical psychologists who
used the Adult ADHD Clinical Diagnostic Scale. Although there is no standard
method for diagnosing adult ADHD, this scale has been used in adult-ADHD
Kessler and his team then used both the initial interview results and the
reappraisal-interview results to derive an estimated prevalence of adult ADHD
for the entire sample of 3,199 participants. The estimate prevalence they
obtained was 4 percent.
Moreover, Kessler and his colleagues learned, survey participants who had
adult ADHD were more often male than female; were often unemployed, no longer
married, and impaired in such areas as thinking, taking care of themselves,
and getting about; and often had other mental illnesses, notably anxiety,
depression, a substance use disorder, or intermittent explosive disorder.
Only 10 percent of those diagnosed with adult ADHD were receiving treatment
for it. This is a much lower percentage than the number of Americans being
treated for anxiety, mood, and substance use disorders.
Their results, Kessler and his coworkers noted, make one wonder whether
treatment of adult ADHD might mitigate the mental illnesses that often
accompany the condition. After all, they explained, a diagnosis of adult ADHD
requires that at least some of the symptoms of ADHD began before the age of 7,
so the mental conditions that often accompany it probably occurred at a later
age and perhaps in response to the ADHD.
Indeed, the researchers pointed out, successful treatment of ADHD in
children often reduces the symptoms of mental disorders that frequently occur
along with ADHD.
Taken together, Kessler and his team concluded, their results regarding
adult ADHD were mostly what they had expected. However, one finding did
surprise them—a lower prevalence of adult ADHD among blacks and
Hispanics than among whites. This outcome, they reasoned, could reflect true
racial or ethnic differences or perhaps a greater acceptance of ADHD symptoms
by blacks and Hispanics.
"This is a well-designed, cross-sectional study of the prevalence of
adult ADHD," Tony Rostain, M.D., director of education in the University
of Pennsylvania Department of Psychiatry and an adult ADHD authority, told
Psychiatric News. "The authors used rigorous methods to screen
and interview 154 respondents in order to determine the rate of ADHD
diagnosis, as well as demographic correlates and comorbid disorders seen in
subjects with ADHD.
"Their finding that 4.4 percent of the adult population meets
criteria for ADHD is credible, as are the findings of significantly increased
rates of depression, anxiety, substance abuse, and intermittent explosive
disorder in this group. Finally, the low rates of treatment for ADHD that
these patients are receiving underscores the importance of careful screening
for the disorder, especially in adult patients being treated for depression,
anxiety, and substance abuse."
The National Comorbidity Survey Replication was funded by the National
Institute of Mental Health, the National Institute on Drug Abuse, the
Substance Abuse and Mental Health Services Administration, the Robert Wood
Johnson Foundation, and the John W. Alden Trust. Additional support for the
adult ADHD assessments came from a grant from Eli Lilly and Co.
"The Prevalence and Correlates of Adult ADHD in the United
States: Results From the National Comorbidity Survey Replication" is