ADD / ADHD Delayed Brain Maturation--Controlled for Medication?

Brain development in puberty is sensitive to many environmental factors. Children with learning disabilities may have delays in cortical development of from 3-5 years or more, for various reasons. More recent brain imaging studies focusing on ADD / ADHD provide further evidence that some learning disabilities involve brain maturation delays beyond the normal pubertal delays in frontal and pre-frontal cortex maturation.

The scientists at the National Institutes of Health (NIH) compared the brain scans of 446 children ranging from pre-schoolers to young adults.

Of the group 223 had been diagnosed with ADHD.

Magnetic resonance imaging (MRI) scans of the brain were carried out twice at around three-year intervals.

The researchers found that the delay in ADHD was most prominent in regions at the front of the brain's outer mantle (cortex), which is important for the ability to control thinking, attention and planning.

Other than this both groups showed a similar back-to-front wave of brain maturation with different areas peaking in thickness at different times.

The imaging study revealed that in youngsters with ADHD, the brain matures in a normal pattern but is delayed on average three years in some regions.

Dr. Philip Shaw who led the research says that finding a normal pattern of cortex maturation, even though it is delayed, in children with ADHD should reassure parents and may also explain why many youngsters eventually appear to grow out of the disorder.

Dr. Shaw and colleagues at the National Institute of Mental Health (NIMH) Child Psychiatry Branch, were able to detect the thickening and thinning of thousands of cortex sites by using a new image analysis technique which picks up the focal and regional changes where the delay is most marked.

Source

The developing brain is sensitive to environmental insults from alcohol, marijuana, other drugs and chemicals, infection, trauma etc. It is too early to tell if sufferers from ADD / ADHD and other childhood learning disabilities suffered such environmental insults early in their lives, or whether genetic factors are involved.

It is also unclear what effect drug treatment for ADD / ADHD may have on the studied pattern of pubertal cortical maturation. It seems likely that other non-pharmaceutical approaches for encouraging cortical development would be even more effective than pharmacological interventions, or would at least have less potential to harm the developing brain. Time will tell.

As child psychiatrists become emboldened by such studies to devise and encourage alternative treatments for ADD / ADHD, perhaps a future imaging study that controls for medication use will reveal what effect high dosage stimulant use has on the cortical development young children. A child psychiatrist of my acquaintance commented that it will take a lot of effort to break the addiction to stimulants that has taken hold of the schoolteachers, parents, and mental health professionals of North America. He suggested, rather cynically, that billions of dollars are at stake for big Pharma.