Antidepressants an untold story?

BMJ 2008;336:532-534 (8 March)(published 27 February 2008)
By: Jeanne Lenzer, medical investigative journalist, New York.

• New generation antidepressants aren’t all they’re cracked up to be.
• That seems to be the central message in the meta-analysis published this week by Irving Kirsch and colleagues in PLoS-Medicine, and it was this message that made the headlines.
• Kirsch’s conclusion follows on the heels of similar studies showing that statins are useful in only a small subset of patients taking the drugs and earlier studies showing that the safety and performance of cyclo-oxygenase-2 inhibitors seemed better than proved to be the case, further reinforcing previous criticisms that regulators in the United Kingdom and the United States are not doing their duty to protect the public from useless and dangerous drugs.
• But there’s another, deeper problem here—a problem that, ironically enough, was highlighted by GlaxoSmithKline’s news release stating that Kirsch’s conclusions are “incorrect” because he evaluated only a “small subset of the total data available.”
• How can regulators, the public, and doctors know how useful (or how potentially dangerous) drugs really are unless outside researchers have access to all the data?

But do we know the truth about antidepressants even now? Or statins? Or any one of many other drugs currently on the market?

• The answer to that isn’t as simple as it might seem.
• Firstly, there’s the problem of publication bias, the tendency for positive studies to get published and negative studies to be filed away in a drawer. In the case of antidepressants, a 2008 analysis by Erick Turner and colleagues published in the New England Journal of Medicine found that only 8% of antidepressant trials with negative findings were reported as negative, while positive trials were reported as such 97% of the time.
• The problem is not limited to antidepressants, says Turner. A former medical examiner for the FDA, Turner recently told the BMJ that it is critical for researchers to be able to obtain complete study protocols and full datasets to be able determine whether a study’s conclusions are valid.
• His concerns were highlighted by a 1999 study showing that in five top medical journals the authors’ conclusions as stated in journal abstracts either were not supported or were contradicted by data given in the body of the article in 18% to 68% of articles (depending on journal).