The most highly viewed Brain Post of 2012 examined a study of brain development, IQ and ADHD.
ADHD rates are increased in lower IQ children but can be found in those with normal and above normal IQ performance.
This study looked at a sensitive measure of brain development and compared the structural brain patterns of children with ADHD with low IQ and children with ADHD with normal IQ.
The study found two distinct patterns related to brain development in these two groups:
Low IQ children with ADHD showed delay brain gray matter development in the prefrontal cortex region compared to control children
High IQ children with ADHD had reduced gray matter volume throughout the brain but no focal developmental abnormality patterns
These results suggest more than one brain developmental abnormality in ADHD. Future studies of brain structure, brain function and genetic risk factors will need to consider controlling for IQ performance.
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