ADHD and Brain Structure and Function

ADHD is a neurodevelopmental disorder. Over the last several years, there’s been increasing evidence that the brain’s structure and function might differ between someone with ADHD and someone without the disorder. Understanding these differences can help lessen the stigma sometimes associated with ADHD.

ADHD is characterized by difficulties with paying attention and, in some cases, extreme hyperactivity. Someone with ADHD may experience either attention deficit or hyperactivity more. ADHD is usually diagnosed during childhood, but it can also be identified for the first time in adulthood. Other symptoms include:

  • lack of focus
  • fidgeting
  • difficulty staying seated
  • overactive personality
  • forgetfulness
  • talking out of turn
  • behavioral problems
  • impulsiveness

The precise cause of ADHD isn’t known. Genes are thought to play a large factor. There are other possible contributing factors, such as:

  • nutrition, although it is still controversial whether or not there is an association between ADHD and sugar consumption, according to a study in the journal Nutrition Research and Practice
  • brain injuries
  • lead exposure
  • cigarette and alcohol exposure during pregnancy

The brain is the most complex human organ. Therefore, it makes sense that understanding the connection between ADHD and both brain structure and function is also complex. Studies have researched whether there are structural differences between kids with ADHD and those without the disorder. Using MRIs, one study examined children with and without ADHD over a 10-year period. They found that brain size was different between the two groups. Children with ADHD had smaller brains by about 3 percent, although it is important to point out that intelligence is not affected by brain size. The researchers also reported that brain development was the same in children with or without ADHD.

The study also found that certain areas of the brain were smaller in children with more severe ADHD symptoms. These areas, such as the frontal lobes, are involved in:

  • impulse control
  • inhibition
  • motor activity
  • concentration

Researchers also looked at the differences in white and grey matter in children with and without ADHD. White matter consists of axons, or nerve fibers. Grey matter is the outer layer of the brain. Researchers found that people with ADHD may have different neural pathways in areas of the brain involved in:

  • impulsive behavior
  • attention
  • inhibition
  • motor activity

These different pathways might partly explain why people with ADHD often have behavioral issues and learning difficulties.

The Journal of Attention Disorders reports there may also be gender differences in ADHD. One study found that gender was reflected in the results of performance tests measuring inattention and impulsivity. The tests results showed that boys tend to experience more impulsivity than girls. There was no difference in inattention symptoms between boys and girls. On the flipside, girls with ADHD may experience more internal issues, such as anxiety and depression, especially as they get older. However, the difference between genders and ADHD still requires further research.

Treatment is necessary to improve quality of life in ADHD. For those under the age of 5, the Centers for Disease Control and Prevention recommends behavioral therapy first. Early intervention can:

  • decrease behavioral problems
  • improve school grades
  • help with social skills
  • prevent failures in finishing tasks

For children over the age of 5, medications are generally considered the first line of ADHD treatment. Some lifestyle measures may help, too.


When it comes to effective ADHD management, prescription medications continue to be the first line of treatment for most kids. These come in the form of stimulants. While it might seem counterproductive to prescribe stimulating medication for someone who is already hyperactive, these drugs actually have the opposite effect in ADHD patients.

The problem with stimulants is that they can have side effects in some patients, such as:

  • irritability
  • fatigue
  • insomnia

According to the McGovern Institute for Brain Research, about 60 percent of people respond favorably to the first stimulant they are prescribed. If you aren’t happy with a stimulant medication, a nonstimulant is another option for ADHD.

Lifestyle Changes

Lifestyle changes can also help control ADHD symptoms. This is especially helpful for children who are still building habits. You may try:

  • limiting television time, especially during dinner and other times of concentration
  • getting involved in a sport or hobby
  • increasing organizational skills
  • setting goals and attainable rewards
  • sticking to a daily routine

Since there is no cure for ADHD, treatment is necessary to improve quality of life. Treatment can also help children succeed in school. Despite some of the challenges often seen in childhood, some symptoms improve with age. In fact, the National Institute of Mental Health (NIMH) notes that the brain of an ADHD patient does reach a “normal” state, but it’s just delayed. Also, despite gender differences within brain structure and function within ADHD, it’s important to note that males and females undergo the same treatments.

Ask your doctor if your child’s current treatment plan may need a second look. You may also consider talking to professionals at your child’s school to explore possible supplemental services. It’s important to remember that with the right treatment, your child can live a normal and happy life.


Is it true that ADHD is under recognized in girls? If so, why?

Anonymous patient


ADHD has long been associated with boys and hyperactive behavior. Many cases of ADHD are brought to the attention of parents by teachers who note the child’s disruptive behaviors in class. Hyperactive behavior by its very nature is more distracting or problematic than the inattentive behavior often seen in girls with ADHD. Those with inattentive symptoms of ADHD generally do not claim the attention of their teachers and, as a result, are often not recognized as having a disorder.

Timothy J. Legg, PhD, PMHNP-BCAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.