New MRI Research: Children with ADHD Have Few Scan Contrasts

A new study led by a Duke University School of Medicine researcher found that children with ADHD showed few differences in their brain MRI scan compared to unaffected children.

Researchers analyzed the MRI brain scans of over 10,000 children aged 9-10 years old to conduct the test. Of them, 949 had ADHD. They compared the children who met the criteria of having ADHD with those who did not and found only 11 differences across 79 brain measures, noting that the differences were too minor to be helpful in diagnosing the disorder.

Attention-deficit/hyperactivity disorder (ADHD) is a very common mental disorder, affecting 8.4% of children and 2.5% of adults. Symptoms often include the inability to focus, inability to sit still, and impulsivity.

ADHD is often most noticeable at a young age when it inevitably becomes apparent while doing schoolwork and disrupting the classroom. It can be more pronounced in children because their difficulty to pay attention and hyperactivity is much greater than expected for their age, and it can cause distress at school and with friends.

The inattentive type’s typical symptoms are:

• Doesn’t pay attention to details at work or in school
• Doesn’t pay attention when being spoken to 
• Has trouble organizing and completing tasks 
• Avoids tasks that require mental energy 

The hyperactive type’s common symptoms include: 

• Constantly fidgets, squirms or taps feet and hands
• Has trouble staying seated
• Talks too much 
• Inappropriately runs or climbs on things
• Blurts out answers and interrupts in class

The combined type has both of these types of symptoms.

There is no brain scan or lab test that can diagnose the disorder. Instead, it’s diagnosed through a medical examination (to rule out medical problems) and gathering information about the patient through parents, teachers, etc.

The cause for the disorder is unknown, and this study has further proven there are few physical differences in a child with ADHD’s brain versus an unaffected child. There is evidence that is it is genetic – three out of four children with the disorder have a diagnosed relative.

Researchers and scientists continue to examine other possible factors contributing to symptoms, such as brain injuries, being born prematurely, the mother smoking or drinking while pregnant, or extreme stress while pregnant.