WEDNESDAY, Jan. 7, 2026 (HealthDay News) — For decades, doctors assumed ADHD medications like Ritalin and Adderall work by fixing problems in the brain’s attention system.
A new study suggests that assumption may be wrong.
Instead of acting on attention centers, these stimulant drugs appear to target the brain’s reward and wakefulness centers, according to new research published in the journal Cell.
“When I first saw the results, I thought I had just made a mistake because none of the attention systems are changing here,” study author Dr. Benjamin Kay, a professor of neurology at Washington University School of Medicine in St. Louis, told The Washington Post.
The researchers analyzed brain scans from nearly 5,800 8- to 11-year-olds who took part in the long-running Adolescent Brain Cognitive Development study.
Some had taken prescription stimulants on the day of their scan. Others had not.
When scientists compared the two groups, they found clear differences — but not where they expected. The drugs increased activity in brain regions tied to reward and wakefulness, not attention.
That doesn’t mean the medications don’t help.
“The paper clearly shows that they help,” study co-author Dr. Nico Dosenbach told The Post. “They help kids who have a diagnosis of ADHD do better in school and do better on tests, and they help kids who don’t sleep enough ? and a lot of Americans don’t sleep enough.”
Dosenbach, who is also a professor of neurology at Washington University, explained that the drugs may help by making boring tasks feel more rewarding.
They “pre-reward our brains and allow us to keep working at things that wouldn’t normally hold our interest,” he added.
ADHD affects an estimated 7 million U.S. children ages 3 to 17, and about 15.5 million adults. Rates among children rose from 6.1% in the late 1990s to more than 10% by 2016, one study found.
The new study also highlighted the role of sleep.
The stimulants not only helped kids with ADHD, but also children without an ADHD diagnosis who slept less than the recommended nine hours a night.
But the medications didn't improve school performance in children who slept well and did not have ADHD.
In short, sleep matters a lot, experts said.
“Despite the name ‘Attention Deficit,’ ADHD is a multifaceted disorder in which difficulty focusing attention is just one component,” said Maggie Sweitzer, a psychiatry professor at Duke University School of Medicine in Durham, North Carolina, who reviewed the findings.
"It’s important to remember that ADHD is not a benign condition — individuals with ADHD are not only at risk for school problems in childhood, but also for occupational, social, and physical, and mental health problems across the lifespan. For many people these medications are transformative," Sweitzer added.
Jessica Lunsford-Avery, a child development and behavioral health specialist at Duke, also reacted to the findings.
“Sleep disturbances are incredibly common in ADHD, impacting about 3 out of 4 children and adolescents with the disorder,” she told The Post in an email.
“It is increasingly clear that clinicians and families should view ADHD as a 24-hour disorder," Lunsford-Avery added. "Unfortunately, sleep problems are rarely recognized or adequately treated in children and adolescents with ADHD.”
Doctors emphasize that prescription stimulants are not the same as energy drinks or caffeine.
Dr. Sinan Omer Turnacioglu of Children’s National Hospital in Washington, D.C., noted that prescription stimulants “don’t work in the exact same way in the nervous system.”
He added that healthy sleep habits such as limiting screen time before bed and having a calming routine are important.
More information
The Cleveland Clinic has more on ADHD medications.
SOURCE: The Washington Post, Jan. 6, 2026