Doctors and parents may have been misled about the safety and effectiveness of the  medications used to treat attention-deficit hyperactivity disorder (ADHD).   According to The Washington Post, the  recently published findings of the Multimodal Treatment Study of Children (MTA) indicate that such drugs are no more effective than other treatments in the long-term, and and may also stunt childrens’ growth.  But when  initials findings  of the MTA study were released in 1999 and 2007,  ADHD drugs were presented in a much more positive light.

The  MTA study was designed to test whether children diagnosed with ADHD do better when treated with drugs, with drugs plus talk therapy, with talk therapy alone or with routine medical care alone.   The study’s purportedly positive findings are one of the reasons the use of ADHD drugs has exploded in the past several years.    In 2004, physicians wrote 28.3 million prescriptions for ADHD drugs; last year, they wrote 39.5 million, the Post said.

According to the Washington Post, the initial results from MTA published over a decade ago  showed clearly that those treated with medication did much better than those who got only talk therapy or routine care.  Drug makers, of course, took advantage of the findings, and used the initial results in promotional materials.

The first follow-up results were issued in 2007.  They no longer showed differences in behavior between children who were medicated and those who were not.  What’s worse,  the study also showed that children on drugs for three years were shorter and lighter than their non-medicated counterparts.

But according to the Post, those results were presented in a more positive light in a July 2007 news release issued by the National Institute of Mental Health.  For example, instead of saying that the growth of medicated kids was stunted, the release said that non-medicated children “grew somewhat larger.”

According to The Washington Post, over the past several years, the study continued to show little difference between medicated and non-medicated children.  Some of data were published online Thursday in the Journal of the American Academy of Child and Adolescent Psychiatry.

One principal scientist in the study, psychologist William Pelham of the State University of New York at Buffalo,  told the Post  that the most obvious interpretation of the data is that the medications are useful in the short term but ineffective over longer periods.  But Pelham claims his colleagues had repeatedly sought to explain away evidence that challenged the long-term usefulness of medication, the Post said.

“The stance the group took in the first paper was so strong that the people are embarrassed to say they were wrong and we led the whole field astray,” Pelham told the Post. “