continentalgrip t1_ivpeojz wrote
Reply to comment by bekilledoff in New study (n=276) finds that a standardized mindfulness program is as effective as a common antidepressant (Escitalopram) at treating anxiety, with both treatments leading to about a 30% reduction in symptoms. by fotogneric
"Thus, we had data on unpublished trials as well as published trials. This turned out to be very important. Almost half of the clinical trials sponsored by the drug companies have not been published (Melander, Ahlqvist-Rastad, Meijer, & Beermann, 2003; Turner, Matthews, Linardatos, Tell, & Rosenthal, 2008). The results of the unpublished trials were known only to the drug companies and the FDA, and most of them failed to find a significant benefit of drug over placebo. A second advantage of the FDA trials in the FDA dataset is that they all used the same primary measure of depression – the Hamilton depression scale (HAM-D). That made it easy to understand the clinical significance of the drug-placebo differences. Finally, the data in the FDA files were the basis upon which the medications were approved. In that sense they have a privileged status. If there is anything wrong with those trials, the medications should not have been approved in the first place.
In the data sent to us by the FDA, only 43% of the trials showed a statistically significant benefit of drug over placebo. The remaining 57% were failed or negative trials. Similar results have been reported in other meta-analyses (Turner et al., 2008), including one conducted by the FDA on the clinical trials of all antidepressants that it had approved between 1983 and 2008 (Khin, Chen, Yang, Yang, & Laughren, 2011). The results of our analysis indicated that the placebo response was 82% of the response to these antidepressants. Subsequently, my colleagues and I replicated our meta-analysis on a larger number of trials that had been submitted to the FDA (Kirsch et al., 2008). With this expanded data set, we found once again that 82% of the drug response was duplicated by placebo.
More important, in both analyses, the mean difference between drug and placebo was less than two points on the HAM-D. The HAM-D is a 17-item scale on which people can score from 0 to 53 points, depending on how depressed they are. A six-point difference can be obtained just by changes in sleep patterns, with no change in any other symptom of depression. So the 1.8 difference that we found between drug and placebo was very small indeed – small enough to be clinically insignificant.
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