Ritalin, the drug commonly used to treat attention deficit/hyperactivity disorder (ADHD) in children, may have the potential to cause changes in their brains, according to a new study at Weill Cornell Medical College in New York.
The study, recently mentioned in the Journal of Neuroscience, was conducted by injecting baby male rats twice a day with Ritalin (methylphenidate) from a week after their birth until they were 35 days old. At the conclusion of the study, researchers found changes in four parts of the rats' brains.
"First, we noticed alterations in brain chemicals such as catecholamines and norepinephrine in the rats' prefrontal cortex -- a part of the mammalian brain responsible for higher executive thinking and decision-making," said Teresa Milner, senior author of the study and a professor of neuroscience at Weill Cornell, in a press release.
Changes were also detected in the hippocampus, which controls memory, as well as the striatum, which affects motor function. Finally, scientists saw alterations in the hypothalamus, the area of the brain involved in appetite, emotions and arousal.
Milner and Jason Gray, a graduate student who was a lead author on the study, noted that the doses of Ritalin used on the rats corresponded to a fairly high dose in human children. The rats were also treated with the drug at an earlier age than most human children begin treatment, though Gray noted that Ritalin studies are currently being conducted on 2- and 3-year-old children.
In addition to the changes in the rats' brains, researchers also noted that the rats lost weight, much like human patients do once starting on the drug. Also, three months after receiving their last Ritalin injections, the treated rats seemed to display fewer signs of anxiety than subjects that received no drugs.
Despite the results of the study, Milner said that Ritalin use isn't necessarily harmful to children. In fact, children who have ADHD may have an out-of-balance brain chemistry, and Ritalin may help restore the proper balance of chemicals. "On the other hand, in brains without ADHD, Ritalin might have a more negative effect," Milner said. "We just don't know yet."
It's also important to note that three months after they stopped receiving the drug, the rats' brains had mostly returned to normal - an encouraging find, Milner said, which may support the assertion that Ritalin should only be used in children over a short period of time. "We're concerned about longer-term use," she said.
Weill Cornell Medical College Press Release - "Pediatric Ritalin Use May Affect Developing Brain, New Study Suggests." Available at: http://news.med.cornell.edu/wcmc/wcmc_2007/07_17d_07.shtml
"ADHD Drug Does Stunt Growth
After 3 Years on Ritalin, Kids Are Shorter, Lighter Than Peers
July 20, 2007 – After three years on the ADHD drug Ritalin, kids are about an inch shorter and 4.4 pounds lighter than their peers, a major U.S. study shows.
The symptoms of childhood ADHD -- attention deficit hyperactivity disorder -- usually get dramatically better soon after kids start taking stimulant drugs. But this benefit may come with a cost, says James Swanson, PhD, director of the Child Development Center at the University of California, Irvine.
"Yes, there is a growth suppression effect with stimulant ADHD medications," Swanson tells WebMD. "It is going to occur at the age of treatment, and over three years it will accumulate."
Whether these kids eventually grow to normal size remains a question. Kids entered the study in 1999 at ages 7 to 9. The current report is a snapshot taken three years later. The 10-year results -- when the kids are at their adult height -- won't be in for two more years.
"The big question now is whether there is any effect on these kids' ultimate height," Swanson says. "We don't know if by the time they are 18 they will regain the height."
The finding appears to end decades of debate over whether stimulant medications affect children's growth. Less than 10 years ago, a National Institutes of Health panel concluded that the drugs carried no long-term growth risk.
That opinion was so widely accepted that the study authors -- who include most of the leading ADHD researchers in the U.S. -- did not warn parents that the study medication might carry this risk.
At the time, researchers thought that any short-term stunting of growth would be made up by a hypothesized "growth spurt" that would occur with continued treatment. But Swanson and colleagues saw no evidence of such a growth spurt.
Another widely accepted theory was that ADHD itself stunted kids' growth. But in a surprise finding, the study found that ADHD kids who do not take stimulant drugs are much larger than kids without ADHD. And these untreated kids continued to grow much faster than kids taking stimulant drugs.
Swanson says that children who had been taking ADHD drugs before the study began were smaller than kids who had not yet started treatment. Those who first began treatment at the start of the study were normal in size, but grew more slowly than normal kids as the study went on.
After three years, the growth suppression seemed to reach its maximum effect. That's also when the effect of the ADHD drug used in the study -- immediate-release Ritalin three times a day, every day of the year -- seemed to wear off.
"We compared the effect of medication relative to just pure behavioral treatment," Swanson says. "That effect was substantial at 14 months and reduced a bit at 24 months. But at 36 months the relative advantage of ADHD drugs over behavioral treatment is gone."
Swanson and colleagues note that the study did not test the sustained-release stimulant medications that are now the standard treatment for ADHD.
Omar Khwaja, MD, PhD, a neurologist at Children's Hospital in Boston, last year analyzed studies of different ADHD drugs and found strong evidence that ADHD drugs do, indeed, stunt children's growth. In fact, Khwaja and colleagues calculated a growth effect that almost exactly matches the effect seen in the Swanson study.
But Khwaja agrees with Swanson that nobody yet knows what the long-term results of this side effect will be.
"Whether there will be rebound growth at end of puberty, the jury is still out," Khwaja tells WebMD.
"Parents have to be aware that stimulants are an enormous benefit to a lot of children with ADHD, but there is reason to be cautious with all medicines that affect the brain," he says. "Growth monitoring should be standard practice for kids taking these medications."
Swanson and colleagues report their findings in the August issue of the Journal of the American Academy of Child and Adolescent Psychiatry.
Other findings from this large study show that both ADHD drugs and behavioral therapy work in children"
Crime risk with Ritalin
Article from:
By Kate Sikora
July 26, 2007 12:00am
CHILDREN who use Ritalin for a long period of time could be more at risk of delinquency and substance abuse, a study has found.
Doctors are suggesting children with attention deficit hyperactivity disorder (ADHD) should take a break from medication after three years of use.
An American study - published in the Medical Observer _ has found that while drugs such as Ritalin can initially help sufferers, the benefit of prolonged use is in doubt.
Some children stay on medication until they reach 18, but researchers believe it may not protect them from all the symptoms.
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The US Multimodal Treatment Study of Children revealed the more days of prescribed medication, the more serious delinquency became.
In a cohort of 500 children with ADHD - followed for 36 months until they were 12 - researchers found 27 per cent were at a greater risk of committing crime, compared with 7 per cent among "normative" children.
Substance use also increased to 17 per cent in ADHD children - almost double the normal rate.
More than 30,000 children in Australia take Ritalin or a similar drug.
Jill Sewell, Associate Professor of the Royal Australian College of Physicians, said evidence suggested a break from medication was beneficial.
"Evidence shows that there is very clear benefit of taking medication for 12-18 months, but after three years it is not so clear," she said.
"Often in medications you do have to stop for a period of time to see if it is still effective."
Belrose mother Leanne Komaromi said she took her son Dominic off Ritalin after four months.
"It made him a completely different person - it shut him down," she said. "It was like someone had drawn the blinds on him."
The nine-year-old now uses the Dore program, which relies on exercise to treat symptoms."