If you talk to any parent of a child with ADHD, they may talk about differences in behavior that puzzled them before the diagnosis.  And they may talk about unique and extraordinary gifts the child may have. But one thing that’s just coming to light about children with ADHD:  Some of the differences are hidden deep inside them.

Scientists have known for a long time that the brains of children with attention deficit problems are visibly different in scans of those aged 6 to 16.  But a new study shows that distinctions show up in the brains of children as young as 4 years of age.

A 2018 study calls ADHD “a common neurological disorder with symptom onset early in childhood.”  The subjects of the study were children four to five years old, some of whom showed symptoms and some did not.  The researchers found that certain areas of the brain were measurably smaller in those children with symptoms. In fact, the more extreme the behavioral issues, the smaller those brain areas were. The study stated, “higher ratings of hyperactive/impulsive symptoms were associated with reduced cortical volumes.”

This discovery in young children is an important finding because the diagnosis of ADHD usually is made after a child is in school, when the behavioral manifestations become an issue for classroom management or social situations. Before that time, the hyperactive/impulsive behavior is seen as less remarkable because children under four aren’t typically required to sit still and concentrate in the way needed in a classroom situation.

However, parents, sitters, daycare personnel and preschool teachers often note that some children are more exuberant than others, even before the more formal school settings. The American Academy of Pediatrics has guidelines to help determine if a child or adolescent has ADHD.

According to a New York Times article, the researchers were very surprised to discover the brain differences in four year olds with ADHD. But they are very encouraged, the article says, because they know that many children grow out of it.