MRI technique shows ADHD patients have low iron in brain
A postdoctoral research fellow at the Medical University of South Carolina used magnetic field correlation (MFC) imaging to show that of 22 kids with ADHD, the 12 that had never been on medication had significantly lower MFC than the 10 who had been on psychostimulant meds (or the 27 kids who did not have ADHD).
http://www.sciencedaily.com/releases/2013/12/131202082644.htm