This study took about 200 adults, half with ADHD, and put them in an MRI machine for 9 minutes, to try and better understand the specific neural architecture for adults with ADHD.
Most participants were on medication, but all didn’t take their medications for 24 hours prior to the test. Interestingly there were more women than men, and also interesting was that the participants were all about early to mid-thirties, and most had only been on medication for a couple of years.
The researches expected to see significant differences in all parts of the brain, but in fact only saw difference in the executive control centre, where people with ADHD had stronger connectivity networks.
Mostert, J. C. et al., 2016. Characterising resting-state functional connectivity in a large sample of adults with ADHD. Progress in Neuro-Psychopharmacology and Biological Psychiatry, Volume 67, pp. 82-91.