California has one of the lowest rates of diagnosis in the nation of attention deficit hyperactivity disorder in children, raising questions about the role of regional, economic and cultural differences in identifying what scientists regard as a brain disorder.
Over-diagnosing ADHD and over-prescribing medication to children has been the cause of considerable concern in education and other circles. But some researchers interviewed by EdSource Today say that the state’s relatively low rates may indicate that the condition is being under-diagnosed among some demographic groups. They suggest that some students aren’t getting the treatment they need to succeed in school.
California ranks fifth lowest in the nation – tied with Alaska – in the percentage of children diagnosed with ADHD, according to newly released data from the 2011-12 National Survey of Children’s Health. (Click here to see a map of ADHD rates by state.) In part, California’s ranking reflects low rates of diagnosis among Latinos, who make up 38 percent of the state’s population, and even lower rates of diagnosis among Californians of Asian descent, who make up 14 percent of the state’s population.
It’s not the state’s overall rate of childhood ADHD that raises questions, with 5.2 percent of California children, or 1 in 20, receiving the diagnosis. Rather it is the wide variation in diagnostic rates among different racial and ethnic groups.
Kaiser Permanente researchers found that the rates of childhood ADHD in California were 5.6 percent for whites and 4.1 percent for blacks, but only 2.5 percent among Latino children, and 1.9 percent among children of Asian descent.
The very low rates for Latino and Asian American children stand out as anomalous, said Joshua Israel, associate clinical professor of psychiatry at UC San Francisco. “In just about every country that has been looked at, including China, the rates have been about the same for children – between 3 and 9 percent, with the average closer to 5,” he said. “It’s likely that the true rates for Asians in California would not be 1.9 percent.”
“We know that there are relatively dramatic differences between ethnic groups in rates of diagnosis,” said Ruth Hughes, chief executive officer of the Maryland-based advocacy group Children and Adults with Attention Deficit Hyperactivity Disorder. “Part of it is cultural, part of it is economic, and all of it has to do with the school system and the medical system.”
Under-diagnosing ADHD has serious consequences, said Sandra Loo, an ADHD researcher and assistant professor of psychiatry at the David Geffen School of Medicine at UCLA.
“There is a common perception that ADHD is not as severe as other disorders, when in fact the long-term outcomes of people with untreated ADHD are really horrible,” she said, including high rates of dropping out of school.
In fact, nearly one-third of children with ADHD drop out or delay high school graduation, according to research conducted at the UC Davis School of Medicine.
The American Psychiatric Association’s Diagnostic and Statistical Manual-IV describes the condition as a “persistent pattern of inattention and/or hyperactivity-impulsivity.”
A child must show clear evidence of “clinically significant impairment” in the ability to function in two major settings – school and home – for at least six months, according to ADHD diagnostic guidelines by the American Academy of Pediatrics. In addition, the child must have at least six symptoms of inattention or hyperactivity to an extent that is “disruptive and inappropriate” for the child’s developmental level. Evidence of impairment should be documented in written reports from teachers and parents, and may include an observation of the child by a mental health professional.
Epidemiological studies of brain disorders find that prevalence is fairly constant across geographic regions, which means that rates of childhood ADHD should be roughly the same across the nation. But they’re not. In Kentucky, which has the highest prevalence, the rate is 13.1 percent, while Nevada has the lowest rate of childhood ADHD, with nearly 4 percent of children diagnosed. The national average is 8 percent, according to the survey. Diagnosis rates also vary broadly by region, with the South reporting higher rates and the West reporting lower rates.
How to account for the differences? It’s all about the beliefs and practices of parents, teachers and doctors, researchers say.
“Regional differences generally have to do with how parents interact with the education system and health providers, as well as with the prevailing attitudes of local health providers,” said Samuel Zuvekas, a senior economist at the Agency for Healthcare Research and Quality in the U.S. Department of Health and Human Services. “It’s a complicated dynamic.”
To avoid over- or under-diagnosis of ADHD, the evaluation process is supposed to be thorough. Yet at every step of the way the process can go awry, subject to pressures from schools, doctors and families.
Schools are on the front lines of identifying children who may have ADHD, working with their families and doctors and creating educational plans or accommodations if necessary. It’s a task that school systems don’t uniformly embrace, said Hughes of Children and Adults with Attention Deficit Hyperactivity Disorder. Some teachers and administrators may find the process overwhelming or may balk at the idea of suggesting that a child’s behavior is atypical, while others may be quick to spot a potential case of ADHD.
“There can be subtle, powerful messages in schools about whether kids get identified,” Hughes said. “The same kid who was never identified as having ADHD in one school system can move to another school system and be identified.”
Families, too, vary in their willingness to consider that their child might have a brain disorder, and their willingness to discuss the matter with teachers and doctors.
Another obstacle is that pediatricians, who make the bulk of diagnoses of childhood ADHD, typically aren’t reimbursed for the time it takes to conduct a rigorous evaluation, making the process “particularly challenging for primary care clinicians,” the American Academy of Pediatrics noted.
The need for appropriate diagnosis is considerable, researchers said, given risks at both ends of the spectrum: medicating children who don’t have ADHD or under-treating children who suffer from a disorder that may seriously impair their social and educational functioning.
“I am a researcher, but I am also a medical doctor, and I see the benefit of a carefully made diagnosis,” said Darios Getahun, lead author of the Kaiser Permanente study. “If you identify a child with ADHD in a timely way, and initiate treatment, the outcome will be better learning and better functioning in social situations.”