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ADHD Brain Differences Start as Early as Preschool, New Study Shows


A number of studies have shown there are brain differences in kids and adolescents with ADHD. Now, a new brain imaging study shows that these differences may appear as early as preschool.

The study was published in the “Journal of the International Neuropsychological Society.” It was funded by the National Institutes of Health and the Johns Hopkins Brain Sciences Institute.

Researchers observed 90 kids. They were 4 to 5 years old, and 64 percent of them were boys. Of the group, 52 kids had symptoms of ADHD. (The researchers used cognitive and behavioral measures to identify those kids with ADHD.)

The purpose was to see if the differences in brain structure were evident when ADHD symptoms appeared at an early age.

All of the research subjects were similar in age, gender, socioeconomic status, IQ and language ability. Mark Mahone, Ph.D., director of the department of neuropsychology at Kennedy Krieger Institute in Baltimore, and his team of researchers performed the scans.

Understood experts Ellen BraatenStephanie Sarkis and Sheldon Horowitz reviewed the study. Here’s the takeaway.

Key Findings

Using a 3D MRI, researchers found that a few areas of the brain were smaller in the preschoolers who had ADHD than in the ones who didn’t.

Size differences in certain areas of the brain were linked to hyperactivity and impulsivity. These areas are the bilateral frontal lobe and the parietal lobe, as well as the right temporal lobe. The smaller those areas were, the more severe those symptoms were.

Severity of inattention was linked to differences in just one area of the brain. That area is the left parietal lobe. The smaller that area was, the more trouble with focus a child had.

“The differences in brain development are in the areas of the brain that are most important for attention, response inhibition, planning and working memory,” said Braaten.

Key Takeaways for Parents

This research shows that early symptoms of ADHD are linked to brain differences. The study is small, which limits the ability to generalize for all preschool-age kids with ADHD. But the results are important and match other research findings, says Sarkis.

This kind of study can lead to treatments that can better factor in brain development, says Braaten.

The study also shows that ADHD isn’t due to poor parenting. “It’s a biological condition,” says Horowitz. “Being able to identify features of ADHD in young children is something to embrace, instead of being ashamed of.”

Learn more about what MRIs are telling us about the ADHD brain. Watch an expert explain how ADHD symptoms change over time. And read more about diagnosing ADHD in younger kids.

Getty image by bernardbodo