Brain Primer

Understanding ADHD

  • Reviewed27 Mar 2023
  • Author Karen Weintraub
  • Source BrainFacts/SfN
Boy sitting at desk with hand on face via J-Elgaard

How do our brains determine what to focus on, and for how long? We each process and react to stimuli with varying levels of speed, focus, and responsiveness. But some may have more difficulty maintaining attention or controlling impulses, which can impact expected behavior.

Attention-deficit/hyperactivity disorder (ADHD) is one of the most commonly diagnosed childhood conditions. *From 2016-2019, approximately 10% of children in the U.S. between the ages of 3 and 17 had received an ADHD diagnosis at some point in their lives. The disorder continues into adulthood for at least around 30% of those diagnosed with ADHD, although this estimate may vary.

ADHD is usually characterized by inattentiveness, as well as hyperactivity or impulsive behaviors. Although all young children can be hyperactive, impulsive, and inattentive from time to time, these symptoms are more extreme and last longer in children with ADHD. They often struggle to form strong friendships, and their grades in school can reflect their behavior instead of their academic ability. Executive functions, such as finishing what they start, remembering to bring homework back to school, and following multistep directions, can be especially challenging for those with ADHD. Youths with ADHD also have lower rates of high school graduation and a higher risk of suicide.

No objective diagnostic test currently exists for ADHD, so a diagnosis requires a comprehensive evaluation, including a clinical interview and parent and teacher ratings. Because problems with attention and hyperactivity can be caused by other conditions such as depression, sleep issues, and learning disorders, careful evaluation is always needed to determine whether ADHD is truly the cause of the child’s symptoms. To warrant an ADHD diagnosis, attention and behavioral problems must be severe enough that they interfere with day-to-day functions. In addition, the behavioral issues must be present in more than one context — not only at home or at school, but in both settings.

Although ADHD tends to run in families, no well-defined set of genes is known to be responsible for the condition. Environmental risk factors, such as extreme early adversity, exposure to lead, and low birthweight, can also be involved. People with ADHD do not demonstrate any obvious brain alterations, but research has found that people with ADHD might have differences in brain structure and in the brain’s ability to remodel itself. Some people with ADHD also show unusual activity in brain cells that release dopamine, a chemical messenger involved in rewarding behavior.

ADHD has no cure, but treatments include drugs, behavioral interventions, or both. ADHD medications include stimulants such as methylphenidate, as well as newer, non-stimulant drugs. Some drugs are available in long-acting formulations so children do not have to interrupt the school day to take their medication. Determining the right drug and the right dose might require a period of experimentation and support from a specialist, since dosage is adjusted to how fast a child metabolizes the drug, and to minimize the side effects. Effective behavioral treatments include organizational support, exercise, and meditation.

Adapted from the 8th edition of Brain Facts by Karen Weintraub.

*This statistic was updated March 27, 2023, to reflect the most recent CDC data on ADHD prevalence.

If you or someone you know in the U.S. is struggling with self-harm or thoughts of suicide, visit or call the National Suicide Prevention Lifeline at 988 or 1-800-273-8255.



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