Of note, the gender gap is getting smaller among black children, but not other groups, he said.
"If parents notice changes in their child's school performance and social interaction that persist, they should consult a doctor and see about available ADHD screening services," he said. "Earlier diagnosis and treatment of ADHD leads to better outcomes for these children."
Dr. Roberto Tuchman, director of the autism and neurodevelopment program at Miami Children's Hospital in Florida, agreed that awareness has risen.
"The increase in ADHD over time is likely due to increased recognition of the disorder," Tuchman said. As awareness grows, certain racial and ethnic groups who previously fell under the radar are beginning to be diagnosed, he said.
"As we get more sophisticated in our ability to recognize the symptoms and the behaviors that constitute ADHD, we are beginning to identify more people with it," he said.
Still, despite the increase in rates of diagnosis, ADHD remains underdiagnosed in some populations, especially poor and minority groups. It may be overdiagnosed in others, however, Tuchman said.
"We see privileged children who are in very competitive schools and there is tremendous pressure to perform better, and this may result in diagnosis of ADHD," he said.
The new study backs up this point. Families with higher incomes were more likely to have ADHD diagnoses than poorer families, the researchers found.
Learn more about ADHD from the U.S. Centers for Disease Control and Prevention.
SOURCES: Roberto Tuchman, M.D., director, autism and neurodevelopment program, Miami Children's Hospital; Darios Getahun, M.D., Ph.D., department of
All rights reserved