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Ritalin Stunts Growth of ADHD Children

Jul 23, 2007 | Parker Waichman Alonso LLP

Ritalin therapy for Attention Deficit Hyperactivity Disorder (ADHD) suppresses the growth of children.  Those are the conclusions of a new study conducted by the Child Development Center of the University of California, Irvine which found that children who had taken Ritalin for three years were, on average, one inch shorter and 4.4 pounds lighter than other kids their age.

For years, child development researchers had known that Ritalin did have some affect on patients’ growth rates.   However, they had wrestled with the question of whether this was a long-term problem.  Some researchers had hypothesized that Ritalin’s growth-suppression side effects would eventually wear off, and that patients would experience a growth spurt that would allow them to “catch up” to their peers.  Less than a decade ago, a National Institutes of Health (NIH) panel even issued an opinion that Ritalin presented no long-term growth risks.  Unfortunately, it would seem the NIH was wrong, as the subjects in the Irvine study have yet to show evidence of such a spurt.

The California researchers have been following these ADHD patients since 1999, with most children entering the study when they were between the ages of 7 and 9.  Three years after the study began, researchers discovered that the subjects’ growth did indeed lag behind their peers.  Ritalin’s affect on growth started when treatment began, and accumulated over three years.  What the researchers at Irvine don’t know yet is whether these Ritalin patients will ever catch up and reach average height by the time they hit adulthood.  That data won’t be available for another two years.

The new research also punches holes in a widely-held theory that ADHD itself stunts growth.  The study found that ADHD patients who had never taken Ritalin where much bigger than kids without ADHD.  Children who had been taking Ritalin before the study began where smaller than kids who had not yet started taking the drug.  Those subjects who commenced Ritalin therapy at the start of the study were normal in size at the time, but as their treatment with Ritalin continued, they grew at a slower rate than those children not taking the drug.  

The Irvine study also concluded that the growth suppression seemed to wear off after about three years.  But the advantages of using Ritalin also seem to decline within the same time frame.  While patients using Ritalin show dramatic improvement the first three years of treatment, those benefits subside after 36 months.  Behavioral therapies, on the other hand, while slower to work initially, have longer-lasting benefits.  

This is not the first time Ritalin’s benefits have been called into question.  A small study conducted by he University of Texas and the M.D. Anderson Cancer Center found a link between Ritalin and increased risk of cancer. While this research only involved 12 children, those taking Ritalin all experienced a significant increase in the chromosomal abnormalities associated with an a higher chance of developing cancer.  Other known side effects of Ritalin include loss of appetite, abdominal pain, sleep problems and headaches.