Study: Stimulants for ADHD Affect Wakefulness and Reward, Not Attention

January 26, 2026

Stimulant medications target brain areas that control reward and wakefulness, not attention, suggests new research in the journal Cell that challenges prior thinking about ADHD treatment.¹

For decades, doctors have prescribed stimulant medications — methylphenidate and amphetamine — under the assumption that the drugs directly improve attention and concentration in individuals with ADHD.^{2, 3, 4} However, the new study led by a team of researchers at Washington University School of Medicine in St. Louis posits that prescription stimulants increase alertness and motivation in children with ADHD.

The researchers compared the resting-state functional MRI (fMRI) data of 5,795 children aged 8 to 11 years who participated in the Adolescent Brain Cognitive Development (ABCD) Study. They found that children who took stimulants the day of the fMRI scan showed increased activity in brain regions related to arousal and reward, but no notable changes in regions connected to attention.

“Essentially, we found that stimulants pre-reward our brains and allow us to keep working at things that wouldn’t normally hold our interest — like our least favorite class in school, for example,” lead author Nico U. Dosenbach, M.D., Ph.D., said in a statement.

According to parent reports in the ABCD study, children with ADHD who took a stimulant medication received better grades in school and performed better on cognitive tests than did children with ADHD who were not taking stimulants.

The study’s findings also offer a new understanding of ADHD hyperactivity. In essence, ADHD hyperactivity may be less about having an abundance of energy and more about seeking stimulation and reward.

“Whatever kids can’t focus on — those tasks that make them fidgety — are tasks that they find unrewarding,” Dosenbach said. “On a stimulant, they can sit still because they’re not getting up to find something better to do.”

Stimulant Medications Benefit Sleep-Deprived Children

Another key finding from the study is that stimulant medications may mimic the benefits of a good night’s sleep.

“We saw that if a participant didn’t sleep enough, but they took a stimulant, the brain signature of insufficient sleep was erased, as were the associated behavioral and cognitive decrements,” Dosenbach said.

The ABCD Study reported that children who got less than the recommended nine hours or more of sleep per night and took a stimulant received better grades in school than children who got insufficient sleep and did not take a stimulant. They also received the same grades as well-rested children who did not take a stimulant.

Children with poor sleep may have shown improved academic performance when taking stimulants, but the researchers caution that stimulants do not cure the effects of chronic sleep deprivation.

“While our results appear to show that the cognitive performance of sleep-deprived children benefited from stimulants, we caution that mounting evidence points to cumulative health consequences of long-term sleep deprivation, including increased risk of depression, cellular stress, and neuronal loss,” the researchers wrote.^{5, 6}

Signs of sleep deprivation, such as difficulty paying attention or poor working memory, overlap with ADHD symptoms and may lead to children being misdiagnosed with ADHD when the actual problem is insufficient sleep.

The researchers stress that findings from the study shouldn’t undermine clinicians’ confidence in the effectiveness of stimulants for ADHD. However, it’s important to rule out factors like sleep deprivation before turning to medication.

“Sleep disturbance is a common comorbidity of ADHD and a common complication of stimulant treatment; therefore, clinicians should screen for sleep disturbance in children with ADHD both before and after prescribing a stimulant,” they wrote.⁷

Nearly three-quarters of children with ADHD experience a sleep disorder.⁸ Sleep problems last into adolescence and can aggravate ADHD symptoms during the day for many children.

“We know that teens with ADHD are more likely than their peers without ADHD to get insufficient sleep on school nights,” said Stephen Becker, Ph.D., in his ADDitude webinar, “Why Am I Always So Tired? The Latest Science on Improving Sleep in Children and Teens with ADHD.”

“We’ve also shown that poor sleep impacts academics, including academic performance, organization, and lower grades based on report cards that we’ve acquired from schools and college institutions,” Becker said. “In some of our work with young teens, even after we account for a teen’s initial levels of depressive symptoms or oppositional behaviors, those teens who had sleep problems went on to experience an increase in depressive symptoms and oppositional behaviors.”

The researchers recommend that future long-term studies evaluate whether stimulant users are less likely to get adequate sleep and measure the cumulative effects of sleep loss over the lifespan. In addition, further research is needed into the long-term effects of stimulant use on brain function and whether stimulants increase task-fMRI activation in response to smaller anticipated rewards.

“The ABCD cohort includes a mix of children taking different stimulant medications and diagnosed with different ADHD subtypes; however, it is not powered to investigate the effects of specific medications or ADHD subtypes,” they wrote. “Variability in scan duration and the lack of precise data on timing and formulation (e.g., immediate vs. delayed release) of stimulant administration limited our ability to account for pharmacokinetic effects in the ABCD cohort, potentially leading to an underestimation of stimulant effects on fMRI connectivity.”

View Article Sources

• Facebook
• Twitter
• Instagram
• Pinterest