Study questions widely-used ADHD drugs

18 Feb 2010, 12:02 am   -   Source: AAP
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An Australian study has revealed a "significant lack of effect" of conventional drugs used to treat ADHD.

An Australian study has revealed a "significant lack of effect" of conventional drugs used to treat ADHD, a finding that surprised at least one of its researchers.

Professor Lou Landau was co-author of the WA-based research which investigated the effectiveness of drugs now widely used to treat Attention Deficit Hyperactivity Disorder (ADHD) in children.

The principal medical adviser to the West Australian Department of Health said he did not expect such a strongly negative result.

"Yes, we weren't anticipating that significant effect," Prof Landau told AAP on Wednesday.

"... or the significant lack of effect of the medication."

Prof Landau and fellow researchers pulled data from the nation's long-term Raine Study to assess the health, and other, outcomes of 131 children with ADHD among more than 2,800 Australian families.

It showed how those using conventional ADHD drugs, such as Ritalin and dexamphetamine, had significantly poorer educational outcomes than children with ADHD not using the stimulants.

The drugs were also linked to a "trend toward slightly higher depression scores", the study found, along with a potentially long-term risk factor for heart disease.

Children using ADHD drugs were found to have elevated diastolic blood pressure - which is the minimum pressure in the arteries when the heart is at rest.

Prof Landau said this side effect was known though it was previously thought to occur in children "while on the medication and it drops down when you stop".

"That was the difference that this study showed ... it was having an effect on the blood vessels that persisted," he said.

When it came to educational performance, children on ADHD drugs were shown to be significantly worse off than those with unmedicated or no longer medicated ADHD.

This effect was present even after researchers accounted for the fact that ADHD children with the worst symptoms were most likely to be prescribed the drugs.

"In children with ADHD, ever receiving stimulant medication was found to increase the odds of being identified as performing below age-level by a classroom teacher by a factor of 10.5 times," the study found.

Overall, there was "little long-term benefit of stimulant medication" for ADHD children, the study concluded.

They had roughly the same behavioural and attention problems "regardless of medication use", it said, though "where an effect was noticed, this was in the direction of symptoms worsening with the use of ADHD medication".

The results of the population-based study would need to be confirmed with randomised trial, Prof Landau said, but it did show how parents should not automatically opt for a drug-based treatment for their ADHD child.

"That management is a partnership between the parents, teachers and their doctor," Prof Landau said.

"It has to make sure (ADHD children) are healthy, have educational support and social support and then, in some cases, there may be a role for medication.

"But before making that decision one has to consider the potential short-term benefits against potential risks and possibly not a major change in the long term."

Prof Landau is a co-author of the "Raine ADHD Study: Long-term outcomes associated with stimulant medication in the treatment of ADHD in children" report.

The report was released by the WA government on Wednesday.

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