ADHD Kids Show 3 Year Lag in Brain Development: Study

The brains of children with Attention Deficit Hyperactivity Disorder (ADHD) mature an average of three years later as their peers, a new study by researchers at the National Institutes of Health (NIH) unfolds.

For the study, the team of researchers led by Dr. Philip Shaw of the National Institute of Mental Health compiled data from the brain scans of 446 children - half of whom had ADHD.

The researchers watched some 40,000 points in the brains of children and figured out that specific regions of the brain developed, or thickened (a marker of maturity), at different rates.

Comparing brain scans of children aged 6 to 16 who had the common psychiatric disorder with scans of those who did not, researchers found that some areas in the ADHD brain, particularly those involved in thinking, attention and planning matured an average of three years later than ‘healthy’ brains, but otherwise followed normal patterns of development.

Among the 223 children with ADHD, half of 40,000 cortex sites examined reached peak thickness at 10.5, compared to age 7.5 in a matched group without the disorder.

"Although the delay in cortex development was marked, it could only be detected when a very large number of children with the disorder were included. It is not yet possible to detect such delay from the brain scans of just one individual," Dr. Shaw noted. "The diagnosis of ADHD remains clinical, based on taking a history from the child, the family and teachers."

ADHD, a developmental disorder often of neurological in nature typically presents itself during childhood, and is characterized by typical pattern of inattention and hyperactivity. Other common features of the disorder include forgetfulness, poor impulse control and easy distractibility in kids.

Considered as a persistent and chronic condition for which no medical cure is available, ADHD is most commonly diagnosed in children, of which about 60 percent diagnosed with ADHD retain the disorder as adults. It affects about 5 percent of the world's population.

The findings are reported in online edition of Proceedings of the National Academy of Sciences.