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ADHD Drugs and Safety Where's the Proof?

Despite the current popularity drugs used to treat Attention Deficit Hyperactivity Disorder (ADHD), a recent comprehensive analysis of 27 ADHD drugs has found scant evidence that they are safe, that they help school performance or that one drug is more effective than any other.

The study was undertaken by the Drug Effectiveness Review Project, based at Oregon State University. A review of the report was published in The News Tribune on 17 September 2005.

The study analyzed data from 2,287 trials that studied a total of 27 drugs, among which were Adderall, Concerta, Focalin, Risperdal, Ritalin, Provigil and Wellbutrin. (For a full list, see Table I, below.)

The study found that "No conclusions about comparative effectiveness of different pharmacotherapies for ADHD can be made."

According to The News Tribune, the study also found that:

  • "No evidence on long-term safety of drugs used to treat ADHD in young children" or adolescents.
  • "Good quality evidence is lacking" that drugs used to treat ADHD raise "global academic performance, consequences of risky behaviors, social achievements" and other measures.
  • Evidence of the drugs safety is of "poor quality," including research investigating whether some ADHD drugs may stunt children's growth, one of parent's greatest concerns.
  • The means by which individual drugs work is, in most cases, not well understood.
  • In adults, evidence that drugs used to treat ADHD "is not compelling."
  • In adults, evidence that any one drug "is more tolerable than another" is also not strong.

The study's findings point to the fact that more scientific proof is needed to determine whether the drugs are safe it does not prove that they are unsafe, or unhelpful.

Although he had no specific comment on the report, senior vice president, Ken Johnson of The Pharmaceutical Research and Manufacturers of America (a Washington, DC-based drug industry lobby group) noted that the benefits of most drugs used to treat ADHD "clearly outweigh the risks," according to The News Tribune.

Diagnosis and Prevalence of ADHD

According to the National Institute of Mental Health, ADHD "is a condition that becomes apparent in some children in the preschool and early school years. It is hard for these children to control their behavior and/or pay attention. It is estimated that between 3 and 5 percent of children have ADHD, or approximately 2 million children in the United States. This means that in a classroom of 25 to 30 children, it is likely that at least one will have ADHD.

"The principal characteristics of ADHD are inattention, hyperactivity, and impulsivity. These symptoms appear early in a child's life. Because many normal children may have these symptoms, but at a low level, or the symptoms may be caused by another disorder, it is important that the child receive a thorough examination and appropriate diagnosis by a well-qualified professional."

Drug Effectiveness Review Project

The Drug Effectiveness Review Project was founded in 2003 to provide consumers and state insurance plans with reliable information about pharmaceuticals, including comparative studies.

Many industry studies can be "rigged" for favorable outcomes, notes The News Tribune, and therefore do not provide consumers with the confidence "many of us would like to decide whether or not we should be using a given medication," said the project's deputy director, Mark Gibson.

Moreover, the US Food and Drug Administration (FDA) does not require companies to measure the efficacy of their new drugs against drugs already on the market. Instead, clinical trials most often compare efficacy of the new drug against a placebo, because the contrast more clearly shows benefit, which more easily paves the road for FDA approval.

This leaves consumers with few resources for comparison shopping between drugs of the same pharmaceutical class, or different drugs used to treat the same condition.

The Drug Effectiveness Review Project attempts to address this issue, by analyzing virtually every study on a given class of pharmaceuticals to find the best drugs.

The American Association of Retired Persons and Consumers Union, who publish Consumer Reports, use the Drug Effectiveness Review Project's findings as a basis for advising consumers about which drugs give the most for money. Fourteen states, including Washington, also use the project's services to determine which drugs they should cover for beneficiaries; those states are the project's chief funders.

For their study of drugs used to treat ADHD, the project analyzed published studies, as well as unpublished data from the six leading manufacturers of ADHD drugs. They ultimately rejected 2,107 investigations as unreliable, and reviewed the remaining 180.

Table I. Drugs studied in clinical trials reviewed by the Drug Effectiveness Review Project.

Posted: September 2005