Brain maturation in children with attention-deficit hyperactivity disorder (ADHD) lags several years behind that of children with no psychiatric or neurological ailments, according to a new brain-imaging study.
Developmental delays in ADHD hit a peak of 5 years in regions at the front of the brain's outer layer, or cortex, say psychiatrist Philip Shaw of the National Institute of Mental Health in Bethesda, Md., and his colleagues. These areas assist in controlling attention and in planning upcoming actions.
Kids with ADHD display the same sequence of brain development as healthy youngsters do, the researchers find. Sensory and motor areas attain maximum thickness first, before a thinning-out process begins. Regions that integrate information from different neural sources then do the same. These findings indicate that ADHD involves a slowing, rather than a derailing, of brain maturation, Shaw argues.