Drug manufacturers hide negative data
The January issue of The New England Journal of Medicine took a close look at research on antidepressants to examine whether doctors, patients and regulators get an accurate picture of the effectiveness of medications. They found that drug manufacturers bury negative or inconclusive results, but publish and hype positive results. The result is a misleading view of the effectiveness of medications, a view that over-states their likely effectiveness.
The Journal, one of the most prestigious in medicine, demonstrated that in published studies on the effectiveness of antidepressants, sixty percent of patients benefit from medication, while forty percent "recover" from acute episodes with only the aid of a placebo. If ALL study results are included, however, and not merely those results published by the manufacturers, the overall effectiveness of antidepressants slips to a marginal benefit over placebos. Thus, someone who does not experience significant relief from a particular antidepressant should not be startled: the advantage of any particular medication is very subtle and won't work for many patients.
Previous research has confirmed a similar bias with many other medications--this is not an issue with antidepressants, only. Further, absent adequate regulation by the government, this outcome can be anticipated: no one is as likely to advertise their money-losing failures as they are to advertise their potentially money-earning successes. On the other hand, this may have been the largest study to examine the issue. The NEJM looked at data from 74 clinical trials involving 12 drugs and 12,000 patients, documenting a major difference in publication rates: 94 percent of studies showing a positive outcome were published (37 of 38 trials). Only 14 percent of studies with negative results were published with an accurate description (14 of 36 were published--however, 11 of the 14 placed an unjustified positive "spin" on the outcome).