Brain iron levels may help physicians and parents make better informed treatment decisions when it comes to attention deficit hyperactivity disorder (ADHD), according to a recent study published in the journal Radiology.

ADHD is a common neurobehavioral disorder in children and adolescents than can continue into adulthood. Symptoms include hyperactivity and difficulty staying focused, paying attention and controlling behavior.

Psychostimulant medications such as Ritalin are among the drugs commonly used to reduce ADHD symptoms. They affect levels of dopamine, a neurotransmitter in the brain associated with addiction.

"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," Vitria Adisetiyo, Ph.D., postdoctoral research fellow at the Medical University of South Carolina in Charleston, S.C., said in a statement. "We wanted to see if we could identify brain iron as a potential noninvasive biomarker for medication-naïve ADHD to prevent misdiagnosis."

For the study, the research team 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 using a magnetic resonance imaging (MRI) technique called magnetic field correlation imaging.

They found that 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. In contrast, 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."

Researchers said the magnetic field correlation imaging's ability to noninvasively detect the low iron levels may help improve ADHD diagnosis and guide optimal treatment. Currently, ADHD diagnosis is based only on subjective clinical interviews and questionnaires.

"We are currently testing our findings in a larger cohort to confirm that measuring brain iron levels in ADHD is indeed a reliable and clinically feasible biomarker," Adisetiyo said.