A commonly prescribed drug used to treat attention-deficit/hyperactivity disorder (ADHD) disproportionately affects the development of children’s brains compared to adults with ADHD, according to a new study published in Radiology.
After prospectively giving both boys and adult men either Methylphenidate (MPH)—commonly called Ritalin or Concerta—or a placebo, MR imaging revealed alterations in the white matter development among boys treated with the drug.
"The results show that ADHD medications can have different effects on the development of brain structure in children versus adults," corresponding author Liesbeth Reneman, MD, PhD, said in a prepared statement. "In adult men with ADHD, and both boys and adult men receiving placebo, changes in (fractional anisotropy) FA measures were not present, suggesting that the effects of methylphenidate on brain white matter are modulated by age."
MPH is effective in up to 80% of patients with ADHD, noted Reneman, with the department of radiology and nuclear medicine at the Academic Medical Center, University of Amsterdam, the Netherlands. However, there isn’t much research into its impact on brain development, particularly in relation to white matter—central for learning and coordinating communication between brain regions.
"Previous studies all have tried to statistically control for the effects of ADHD medications," Reneman added. "But we are the first to study medication-naïve patients in this context, which, of course, is crucial if you want to know how ADHD medications affect the developing brain."
The Dutch researchers included 50 boys (aged 10 to 12 years old) and 48 young adult men (23 to 40 years old) diagnosed with ADHD in their study. Each of the two cohorts was split 50/50: half received MPH and the other half received a placebo over 16 weeks.
Patients underwent MR imaging, including diffusion tensor imaging (DTI) before and one week after treatment was concluded. DTI allowed the team to measure FA—thought to indicate important aspects of white matter.
After four months of MPH, boys with ADHD were associated with increased white matter FA, the authors noted. This same trend was not seen in adults treated with the drug.
"What our data already underscore is that the use of ADHD medications in children must be carefully considered until more is known about the long-term consequences of prescribing methylphenidate at a young age," Reneman, who also noted about 5.2% of American children between age 2 and 17 take ADHD medication, said in the statement. “The drug should only be prescribed to children who actually have ADHD and are significantly affected by it."