Low brain iron levels may be an objective biomarker of ADHD, according to a study published in the June 17 online Radiology.
Researchers at the Medical University of South Carolina in Charleston used an MRI technique called magnetic field correlation imaging to measure brain iron levels in 12 children diagnosed with ADHD but who had never taken medication for the condition, 10 children with ADHD who had taken psychostimulants, and 27 children who did not have ADHD. Researchers also measured study participants’ blood iron levels via a blood draw.
Children with ADHD who were medication naïve had significantly lower brain iron levels than other participants in the study, researchers found. Meanwhile, the brain iron levels of children with ADHD who had been treated with psychostimulants and the brain iron levels of children without ADHD were similar, researchers reported, suggesting that psychostimulants cause blood iron to increase to normal levels.
"Our research suggests that iron absorption into the brain may be abnormal in ADHD given that atypical brain iron levels are found even when blood iron levels in the body are normal," said Vitria Adisetiyo, PhD, a postdoctoral research fellow at the Medical University of South Carolina. "We found no differences in blood iron measures between controls, medication-naïve ADHD patients, or psychostimulant-medicated ADHD patients."
If researchers can replicate the potential of low brain iron as a biomarker for ADHD in larger studies, magnetic field correlation could one day help inform clinical diagnoses, which are currently based on subjective interviews and questionnaires.
“This is a significant finding,” said Joseph Helpern, PhD, a professor and researcher at the Medical University of South Carolina.
“It’s hard to come up with quantifiable measurables for these kids. Anything we can get a little hook into that can be objective and quantifiable and has some representation in the disease is big, because we have very little now.”
1. Adisetiyo V, Jensen JH, Tabesh A, et al. Multimodal MR imaging of brain iron in attention deficit hyperactivity disorder: a noninvasive biomarker that responds to psychostimulant treatment? Radiology. 2014 June 17. [Epub ahead of print].