In fact, the adjusted odds of receiving an ADHD diagnosis were 69 percent lower for black children, 50 percent lower for Hispanic children and 46 percent lower for children of other ethnicities, according to the research team, which includes Paul Morgan, associate professor of special education at Penn State. Additionally, among children diagnosed with ADHD, medication use was lower for all minority children.
The researchers reported their findings in the July issue of the journal Pediatrics.
The study also found that disparities in ADHD diagnosis begin in kindergarten and continue until at least eighth grade. Morgan and his co-authors point out that children who are undiagnosed fail to receive interventions that could help mitigate the disorder’s impact on learning and behavior.
“We thought we might see this, but not to this magnitude over this length of time or this early,” Morgan said. “Based on the knowledge base to this point, we didn’t know whether the disparities were occurring in other minority groups, how early they were observed and over what time pattern.”
Previous studies on the subject indicate that minority children, especially black children, are less likely than white children in the U.S. to be diagnosed and treated with ADHD. However, diagnosis patterns over time in early and middle childhood and whether confounding factors explained the disparities were not well understood.
The low odds of minorities being diagnosed with and treated for ADHD is occurring despite other research indicating that minority children display greater ADHD .
“This is a situation where there are a number of different treatments that are empirically validated for this disorder. Minorities are less likely to receive diagnosis and receive medication,” Morgan said. “There are a large number of kids out there not receiving treatment to help with ADHD and that can erode their school-based success.”
There are several theories as to why minorities are less likely to be diagnosed with ADHD, Morgan noted. They include less frequent trips to the doctor and, when seen, less frequent inquiries into developmental concerns; a lower likelihood of referral by school professionals; limited ability to pay for health care; and negative attitudes toward disability identification and treatment in some racial/ethnic subcultures.
Diagnosis is especially important in minority groups, the study reported, because minority children are more likely to be exposed to risk markers for ADHD, including low birth weight, low maternal education, low household income, greater frequency of classroom problem behaviors and lower academic achievement.
“The takeaway point is that there is other empirical research indicating that minorities should be more likely to be diagnosed with due to greater exposure to risk factors,” Morgan said. “But, in our study, they show a consistent pattern of comparative under-diagnosis.
“The study provides support for increased awareness and questioning by health care providers, school psychologists and teachers to ensure minority children receive appropriate diagnosis and care for ADHD, such as medication, therapy, parent training and/or specialized learning programs.”