By HELEN BRANSWELL — Canadian Press
TORONTO (CP) — Hyperactive children across North America are regularly put on Ritalin, a drug that appears to work miracles on the disruptive and impulsive behaviours that are characteristic of attention-deficit hyperactivity disorder.
But a new study points out that while research has conclusively proven Ritalin’s short-term effectiveness, little is known about the long-term efficacy and safety of a drug that some children take for many years.
In fact, the average duration of randomized trials of the drug is 3.3 weeks, notes Ottawa researcher Howard Schachter, lead author of the study published this week in the Canadian Medical Association Journal.
Randomized trials — where participants are randomly assigned to receive the drug being tested or a placebo — are the gold standard of medical research.
“There aren’t long-term studies,” Schachter, a research scientist at the Children’s Hospital of Eastern Ontario in Ottawa, said in an interview.
“And that’s of some concern because we don’t know whether the initial positive effects … might diminish over time. Moreover, we don’t know what happens to the side-effects … whether those get worse or maybe they diminish too — we don’t really know.”
The article by Schachter and his colleagues is one of three in this week’s journal on Ritalin, a hot-button topic.
Ritalin, which is the brand name for a stimulant called methylphenidate, is seen by some as a god-send. Unruly children who disrupt every class they are in behave within minutes of swallowing their pill.
But some worry the exploding numbers of Ritalin prescriptions point to a trend to use the drug not just to treat ADHD, but to control children who have behavioural or emotional problems. Critics worry that instead of getting to the root causes of these problems, doctors and parents are masking the symptoms by medicating these kids.
A second study in the series noted that the number of children in British Columbia who received at least one prescription for Ritalin increased 10-fold in the period from 1990 to 1996.
Is western society creating a time bomb by putting so many children on this drug? Schachter doesn’t think so.
“Given what we know in 40-plus years of using Ritalin, we don’t see horrifically serious side-effects,” he said.
“So is it a time bomb that way? No. Is it controversial? No doubt about it.”
Schachter and his team did what is called a meta-analysis, a research study in which scientists examine all the available research on a subject. Each piece of research could be considered a dot on a piece of paper. The scientists analyse the dots to see what overall picture the accumulated data paint.
That the drug works, and works very quickly, is abundantly clear. But Schachter said it also seems likely that Ritalin does a better job of resolving two of the major problems of ADHD — hyperactivity and impulsivity — than it does of solving the problem of short attention span.
That may mean, he admitted, that while teachers and parents benefit greatly from having a child on Ritalin, the child himself — and most children on the drug are boys — may not see the big gains in attention span he needs in order to thrive in school.
The lack of long-term studies on the drug means science doesn’t know whether children who have taken Ritalin grow up to be more successful adults than children with ADHD who didn’t take the drug.
Schachter rhymes off a list of questions he’d like to see answered:
“How many of them end up in university? What do they do? Do they succeed? What do they end up doing, careerwise?
“Real life questions. Not just ‘Can we control the symptoms in a two-week trial?’ which so many of these studies did.”
His position is echoed in a commentary in the journal by Dr. Benedetto Vitiello of the U.S. National Institute of Mental Health, who led one of the longest studies on Ritalin. That study lasted 14 months.
Vitiello, who works in child and adolescent treatment and preventive interventions at the institute, argues that there are enough well-designed trials to show Ritalin works.
But he admitted the lack of long-term information on whether the drug improves the lives of the children who take it leaves Ritalin’s advocates powerless to silence its critics.
“Until this issues is settled, the treatment of ADHD will continue to find critics arguing that we are just controlling the symptoms but not necessarily improving long-term outcomes,” he wrote.
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