Researchers uncover potential ADHD biomarkerTweet
Parents of inattentive and/or hyperactive children who have a difficult time staying focused or controlling their behavior now may have a new option for properly diagnosing their children with attention-deficit hyperactivity disorder, thanks to a brain-imaging study authored by researchers at MUSC. Published online in the journal Radiology, the study suggests that brain iron levels offer a potential biomarker which may help physicians and parents make more informed treatment decisions.
“Much debate and concern has emerged regarding the continual rise of ADHD diagnosis in the U.S. given that two-thirds of those diagnosed receive psychostimulant medications,” said Vitria Adisetiyo, Ph.D., MUSC postdoctoral research fellow. “We wanted to see if we could identify brain iron as a potential noninvasive biomarker for medication-naïve ADHD to prevent misdiagnosis.”
With the support of a grant funded by the National Institutes of Health to Joseph A. Helpern, Ph.D., and with the collaboration of Jens H. Jensen, Ph.D., Adisetiyo used a magnetic resonance imaging technique called magnetic field correlation imaging that does not require contrast agents to measure iron levels in the brain. Helpern and Jensen of MUSC’s Department of Radiology and Radiological Science invented the technique in 2006.
Researchers measured brain iron levels in 22 children and adolescents with ADHD, 12 of whom had never been on medication for their condition (medication naïve), and 27 healthy control children and adolescents. The 12 ADHD medication-naïve patients had significantly lower brain iron levels than the 10 ADHD patients who had been on psychostimulant medication and the 27 children and adolescents in the control group. Conversely, ADHD patients with a history of psychostimulant medication treatment had brain iron levels comparable to controls, suggesting that brain iron may increase to normal levels with psychostimulant treatment.
“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,” Adisetiyo said. “We found no differences in blood iron measures between controls, medication-naïve ADHD patients or pscyhostimulant-medicated ADHD patients.”
Magnetic field correlation imaging’s ability to noninvasively detect the low iron levels may help improve ADHD diagnosis and guide optimal treatment, since ADHD diagnosis is currently based only on subjective clinical interviews and questionnaires. If the results can be replicated in larger studies, magnetic field correlation might have a future role in determining which patients would benefit from psychostimulants—an important consideration because the drugs can become addictive if taken inappropriately and lead to abuse of other drugs.
For information and resource links, visit http://www.musc.edu/pr/newscenter/2014/adhd-iron.html.