(NaturalNews) More than 30 percent of studies conducted on antidepressant drugs go unpublished, apparently because they fail to show that the drug works as advertised, according to a new study published in the
New England Journal of Medicine.
In addition, published studies often interpret the data as more favorable toward the drug than it actually is.
"Not only were positive results more likely to be published, but studies that were not positive, in our opinion, were often published in a way that conveyed a positive outcome," the researchers wrote.
Although
the FDA requires that pharmaceutical
companies provide the results of all
studies conducted on a new
drug before it receives approval, there is no requirement that those studies be published where
doctors, health researchers and the public can read them. A team of researchers from institutions including the Oregon Health and Science University, the Portland Veterans Affairs Medical Center, Kent State University and the University of California at Riverside compared the
results of studies reported in the
FDA database with whether and how those studies were reported in published literature.
"It tells you where they placed their bets before they saw the data,"
lead researcher Erick Turner said.
The researchers examined 74 studies conducted on 12 antidepressants between 1981 and 2004, involving a total of 12,564
patients. Only 38 of these studies (51 percent) produced favorable results for the
drugs being tested. All but one of those studies - or 94 percent - were published.
In contrast, 22 of the 36 studies that failed to show favorable results (61 percent) went unpublished. Of the 14 studies published, only three interpreted the data unfavorably. The other 11 studies, in contrast with FDA interpretations of the same data, cast the drugs as more effective than they actually were.
For example, of the three studies conducted on Glaxo SmithKline's Wellbutrin, only the one showing positive results was published. Of five studies conducted on Pfizer's Zoloft, the one showing positive results was published; the one with questionable results was spun as if the drug were effective, and the three with unfavorable results were never published.
According to the researchers, the publication
bias inflated the reported effectiveness of the anti-depressant drugs by an average of 32 percent. The actual amount varied from a low of 11 percent for Glaxo SmithKline's
Paxil to a high of 69 percent for Bristol-Myers-Squibb's Serzone.
Turner said that this exaggeration of a drug's effectiveness can lead doctors to prescribe it in borderline cases where it might not be appropriate.
"Selective publication can lead doctors to make inappropriate prescribing decisions that may not be in the best interest of their patients and, thus, the public
health," the researchers wrote.
The researchers said that the publication bias did not necessarily arise from
drug companies actively concealing data. One explanation might be that researchers find negative results uninteresting, and do not go to the effort of writing them up.
"There's an expectation that if you get a positive result, that's what you're supposed to do, and if you get a negative result you have failed," Turner said. "The first impulse is to say, 'I was wrong. Maybe I should move on to something more interesting.'"
The bias could just as easily come from medical journals being more interested in studies with positive results, Turner said, and not from the researchers at all.
Newsweek columnist Sharon Begley expressed skepticism with this view.
"I think he's being too kind," Begley said. "With the proliferation of journals, virtually anything can get published somewhere - maybe not in the
New England Journal of Medicine, but in some third-tier rag, which would still count as 'published.'"
Regardless of the reasons behind it, it is widely acknowledged that publication bias has far-reaching ramifications. It skews the results of meta-analyses, in which researchers compile the results of many published studies to get a better picture of how effective a drug or other therapy is. In extreme cases, it can create a totally false impression: Because studies are typically conducted within a 5 percent confidence interval, it is expected that one in 20 of those studies will show a false result simply due to random variation. If only that study is published and the 19 studies showing no results are never seen, this conveys the opposite impression of what the
research actually found.
While the current study is the most thorough to date examining publication bias in the drug industry, health professionals have long known that this bias is a problem. In 2004, the state of New York sued Glaxo SmithKline for intentionally concealing the results of studies on Paxil in order to make it appear that the drug was more effective on children and adolescents. The company also sought to conceal evidence of dangerous
side effects, the lawsuit alleged, such as an increased incidence of suicidal tendencies.
While that
lawsuit was eventually settled, at least 12 jury trials are scheduled for 2008 that accuse Glaxo SmithKline of hiding suicidal side effects in youths.
As part of the 2004 settlement, Glaxo SmithKline agreed to post the results of all its drug trials on the Internet, and other major companies followed suit. In response to the
New England Journal of Medicine study, spokespeople for several drug companies pointed to this practice as
evidence that the system has been reformed.
But Turner says that posting results online is not the same as publishing them in the
medical literature. He doesn't know a single
doctor, he said, who regularly consults the companies' online databases.
"We are taught that the medical literature is the Holy Grail," he said.
About the author: Mike Adams is a consumer health advocate and award-winning journalist with a strong interest in personal health, the environment and the power of nature to help us all heal He has authored more than 1,800 articles and dozens of reports, guides and interviews on natural health topics, impacting the lives of millions of readers around the world who are experiencing phenomenal health benefits from reading his articles. Adams is an independent journalist with strong ethics who does not get paid to write articles about any product or company. In mid 2010, Adams produced NaturalNews.TV, a natural health video sharing website offering user-generated videos on nutrition, green living, fitness and more. He's also a noted pioneer in the email marketing software industry, having been the first to launch an HTML email newsletter technology that has grown to become a standard in the industry. Adams volunteers his time to serve as the executive director of the Consumer Wellness Center, a 501(c)3 non-profit organization, and regularly pursues cycling, nature photography, Capoeira and Pilates. He's also author of numerous health books published by Truth Publishing and is the creator of several consumer-oriented grassroots campaigns, including the Spam. Don't Buy It! campaign, and the free downloadable Honest Food Guide. He also created the free reference sites HerbReference.com and HealingFoodReference.com. Adams believes in free speech, free access to nutritional supplements and the ending of corporate control over medicines, genes and seeds.
Have comments on this article? Post them here:
people have commented on this article.
Wednesday, August 20, 2008
Email this article to a friend
Share this article on: 
Now Available from 
