Whether Kids With ADHD Get Treated May Depend on Parents' Income

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 of settings.

“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 information.

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 time.

The study revealed that children from wealthy families were more than three times as likely to receive consistent medication treatment as those from less-affluent ones.

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 treatment.”

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 ADHD diagnosis.

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>.▪