Nearly 9 percent of American children—an estimated 2.4
million—meet criteria for attention-deficit/hyperactivity disorder
(ADHD), according to the authors of a new study, yet only one-third who met
ADHD criteria had received consistent treatment for the disorder, prompting
researchers to call for more thorough screening for the disorder in a variety
"We need to increase our awareness of the symptoms of ADHD,"
commented lead researcher Tanya Froehlich, M.D., in an interview with
Psychiatric News. Froehlich is an assistant professor of pediatrics
at the University of Cincinnati College of Medicine.
Froehlich and her colleagues noted in their report that previous research
has discovered ADHD prevalence rates that range from 2 percent to 26 percent
in community samples, due to different modes of ADHD detection.
In her study, Froehlich used the Mental Health Diagnostic Interview
Schedule for Children-IV (DISC-IV), which includes DSM-IV criteria,
to screen for ADHD in a random sample of 3,082 children aged 8 to 15 who
participated in the National Health and Nutrition Examination Survey (NHANES)
between 2001 and 2004. Children who participated in the NHANES were recruited
at random from across the country using the most current U.S. census
For each child assessed, a parent or other caregiver completed the DISC-IV
by phone to provide information about ADHD symptoms his or her child may be
experiencing, age of onset, symptom severity, and related impairments during
the preceding year.
The survey also gathered information on the use of medication for
ADHD-related symptoms during the prior year.
Froehlich found that 8.7 percent of children in her sample met criteria for
ADHD in the year prior to the survey, yet just 38.8 percent of these children
had received medication for symptoms related to the disorder in past year.
About 32 percent indicated consistent use of such medication during that
The study revealed that children from wealthy families were more than three
times as likely to receive consistent medication treatment as those from
The researchers also found that among children in the sample, 3.3 percent
did not meet the DISC-IV criteria for ADHD, but had a parent-reported prior
diagnosis of ADHD and treatment with medications for ADHD symptoms during the
prior year. "It's possible that these children no longer meet criteria
for ADHD because their medications are working well and effectively reducing
their symptoms," Froehlich suggested. On the other hand, she noted, some
may have been placed on medications inappropriately.
In regard to the finding that only about half of those who met criteria in
the study had received medications during the preceding year, she was careful
to note that the study showed "potential" undertreatment,"
since the medications may not benefit every child with ADHD, and some
children may have intolerable side effects" from the medications.
However, she added, "we need to do a better job of diagnosing ADHD,
since children who are not diagnosed have no hope of getting effective
Children from the poorest families in the sample were more than twice as
likely as those from the wealthiest to meet criteria for ADHD, the study
found, and across all income groups boys were twice as likely as girls to meet
criteria for the disorder.
Froehlich suggested that the reasons for the increased likelihood of
apparent ADHD in poor children may stem from an elevated exposure to ADHD risk
factors such as premature birth, prenatal alcohol and tobacco exposure, and
exposure to lead during childhood.
Among children who met DSM-IV criteria for the disorder, just
under half (47.9 percent) had been diagnosed with ADHD by a health
professional. According to the report, several factors, including male gender,
older age, and having health insurance predicted a greater likelihood of prior
Froehlich and her colleagues noted that one of the limitations of their
study was that ADHD diagnosis was based on only the caregiver report, whereas
the American Academy of Pediatrics in its Clinical Practice Guideline on
Diagnosis and Evaluation of the Child With ADHD notes that caregivers and
teachers should be used to help inform a diagnostic evaluation.
In addition, the researchers noted, "medication treatment.. .was
assessed via parent report, whereas review of medical or pharmacy records
would have been preferable."
David Mrazek, M.D., chair of APA's Council of Children, Adolescents, and
Their Families, told Psychiatric News that "while many factors
may be contributing to these modest levels of treatment, one plausible
explanation is that there is still considerable skepticism about the merit of
medication treatment in some cultures. A second possible explanation is that
the cost of treatment is a disincentive."
Froehlich said that future research should investigate whether accounting
for certain modifiable ADHD risk factors such as low birth weight, prenatal
alcohol and tobacco exposure, and childhood lead exposure can explain
differences in ADHD rates between rich and poor children.
"I would also like to see the medical community develop more
innovative systems to improve and streamline the delivery of ADHD
treatment," she said, pointing out that at Cincinnati Children's
Hospital Medical Center, "we are developing a network of school-based
health centers to make it easier" for families to access doctors and for
doctors to work more closely with teachers.
An abstract of "Prevalence, Recognition, and Treatment of
Attention-Deficit/Hyperactivity Disorder in a National Sample of U.S.
Children" is posted at<archpedi.ama-assn.org/cgi/content/abstract/161/9/857>.▪