Posted by Larry Hoover on September 13, 2007, at 18:00:20
In reply to Re: placebo vs. antidepressant » Larry Hoover, posted by linkadge on September 13, 2007, at 16:43:33
> >If these statements were true, what would we >find when we looked at the placebo-controlled >clinical trial data?
>
> We might find analysis like this:
>
> http://www.vaccinationnews.com/DailyNews/June2002/CanPlacebo25.htm
>
> In a soon to be published study, Dr. Arif Khan, a psychiatrist at the Northwest Clinical Research Center in Washington, analyzed the Food and Drug Administration's database of 52 clinical trials in depression, involving nine new antidepressants, conducted from 1985 to 2000. ***Since the agency requires drug companies to report all data from all studies for drugs under development, the database can give a more accurate picture of a new drug's efficacy than the medical journals***, where positive findings are far more likely to be reported than negative ones.
>
> Dr. Khan found that in only 48 percent of the 52 clinical trials was the antidepressant superior to the placebo.
>
> LinkadgeI think it's pretty important to also consider the rest of the text from your referenced article. Beginning with the next sentence after the part you copied:
"Does this really mean that antidepressants are on average no better than placebos for depression? In a word, no....
It turns out that the more severely depressed people are, the less likely they are to respond to a placebo. And people with more mild depressions get better with just about all treatments, including placebos. Since most clinical trials enroll less severely depressed patients, the observed difference between the response to an antidepressant and a placebo can be misleadingly small......it is easy to pick a group of mildly depressed patients and show that a placebo is equivalent to an antidepressant.....
There are other reasons that researchers may mistakenly conclude that placebos are as effective as antidepressants. For example, at least nine clinical trials included in Dr. Khan's meta-analysis lasted only four to five weeks. Yet we know that it can take up to six weeks and more for someone with depression to respond to an antidepressant. For example, studies have shown that about half of patients who had not improved after four weeks of antidepressant treatment responded by Week 6. So studies of short duration can exaggerate the efficacy of placebos.....But why does it matter whether a depressed patient gets better on a placebo or an antidepressant? Isn't the mere fact of improvement proof of efficacy? Well, the problem is that the placebo effect is only short-lived, while depression tends to be a chronic illness with a variable rate of recurrence. Patients who continue on placebos have more than double the risk of relapse to depression than those who stay on antidepressant medication.....At best, a placebo may give the patient a temporary boost if he is mildly depressed, but in a seriously depressed patient, it is right in more ways than one to call it a dummy pill."Lar
poster:Larry Hoover
thread:781684
URL: http://www.dr-bob.org/babble/20070911/msgs/782723.html