The Relationship Between Grey-Matter and ASD and ADHD Traits in Typical Adults.
We tested whether in 85 healthy adults (18-29 years) there is a relationship between grey-matter (GM) volume and autism and ADHD symptom severity.
The structural MRI findings and autism and ADHD self-reports revealed that autism and ADHD symptom severity was correlated with GM volume in the left inferior frontal gyrus.
Autism symptom-severity was correlated with the left posterior cingulate,
ADHD with the right parietal lobe, right temporal frontal cortex, bilateral thalamus, and left hippocampus/amygdala complex.
Symptom severity of both disorders form a continuum extending into the general population, but it seems to be an oversimplification to typify psychiatric disorders such as autism and ADHD solely as extremes of brain structure abnormalities.