Dr. Philip Shaw and his research team at the National Institutes of Health studied 234 children with ADHD and compared them with 231 normally developing children. The researchers scanned each of their brains up to 4 times from age 10 to 17. Their research is published in the journal Biological Psychiatry and mirrors similar research previously performed.
Shaw is particularly interested in surface area of the cerebral cortex — the folded gray tissue that makes up the outermost part of the brain and how it develops during childhood. The researchers’ scans showed that frontal cortex development was delayed in frontal brain regions in the group of children with ADHD. The frontal cortex plays a key role for controlling impulsivity and attention.
The researchers found that in normally developing children, the right prefrontal cortex reached half of its peak area at a mean age of 12.7 years. But the children with ADHD children didn’t reach that mark until 14.6 years; a delay of almost 2 years.
“As other components of cortical development are also delayed, this suggests there is a global delay in ADHD in brain regions important for the control of action and attention,” Philip Shaw, of the National Institute of Mental Health, said in a statement.
Shaw’s findings might encourage scientists to search for the root of this delay and a possible genetic link that controls the timing of brain development.
The research also begs other questions; if ADHD is simply a developmental delay, then why do approximately 65% to 75% of all children carry it into adulthood? Either, it’s not solely a developmental delay or the developmental delay affects long-term brain function. The possibility exists too that it is not a developmental delay at all, but a different brain structure. In the meantime, what is one to do? We suggest strengthening the brain you have. Maximize your capacity. Optimize your life: www.playattention.com.
More information: The article is “Development of Cortical Surface Area and Gyrification in Attention-Deficit/Hyperactivity Disorder” by Philip Shaw, Meaghan Malek, Bethany Watson, Wendy Sharp, Alan Evans, and Deanna Greenstein ( doi: 10.1016/j.biopsych.2012.01.031 ). The article appears in Biological Psychiatry, Volume 72, Issue 3 (August 1, 2012).