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OAK BROOK, III — Attention-deficit/hyperactivity disorder, or ADHD, has become an incredibly common diagnosis in American children. ADHD is characterized by a lack of ability to focus and concentrate, and most children diagnosed with the condition end up being prescribed a medication. A new study offers a warning to parents, however: one of the most popular ADHD meds, Methylphenidate (MPH), may be affecting the development of white matter in children's brains. The drug does not appear to have the same neurological effects in adults.
According to the CDC, roughly 5.2% of all American children between the ages of 2 and 17 are currently taking ADHD medication. Many of those children will continue to take these medications, everyday, well into adulthood.
MPH is usually prescribed and sold under the names Ritalin or Concerta, and while it has been shown to be effective in treating ADHD, there hasn't been enough research performed on how it influences the development of children's brains. More specifically, researchers from the University of Amsterdam set out to analyze MPH's impact on children's white matter development. White matter carries signals between different areas of the brain and is an integral part of learning and overall brain functioning.
In order to do this, researchers gathered 50 boys and 49 adult men, all of whom had been diagnosed with ADHD. None of the participants had taken MPH at all prior to the study.
“Previous studies all have tried to statistically control for the effects of ADHD medications,” explains study senior author Dr. Liesbeth Reneman in a release. “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.”
Participants were then separated into two groups; one group that took MPH each day for 16 weeks, and another that took a placebo every day for the same time period. Both before and one week after the drug trail period each study subject underwent an MRI procedure.
These MRIs assessed each participant's white matter levels, through a measure called fractional anisotropy (FA). Fractional anisotropy describes important white matter readings including nerve fiber density, size, and protection through coating.
An increase in white matter FA was associated with boys who had taken MPH during the 16 week period. However, the same results were not observed in adults who were given MPH.
“The results show that ADHD medications can have different effects on the development of brain structure in children versus adults,” Dr. Reneman says. “In adult men with ADHD, and both boys and adult men receiving placebo, changes in FA measures were not present, suggesting that the effects of methylphenidate on brain white matter are modulated by age.”
While the long-term implications of these findings are still unclear, researchers say the results clearly indicate that MPH influences the development of brain structure in children. Moving forward, Dr. Reneman and his team stress that giving a young child ADHD medication should not be a decision that both doctors and parents make lightly. They recommend that only children who definitively suffer from the disorder, and are significantly affected by it on a daily basis, be prescribed medication.
The study is published in the scientific journal Radiology.
