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MushmanTheManic
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Recent Study by Kirsch, et al. - SSRI's no more effective than placebo
#8069612 - 02/25/08 06:43 PM (15 years, 11 months ago) |
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johnm214



Registered: 05/31/07
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Loc: Americas
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: MushmanTheManic]
#8069694 - 02/25/08 07:05 PM (15 years, 11 months ago) |
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It doesn't say that, it says many prescribed antidepressants aren't any more effective than SSRI's for people that are mildly depressed, and that they aren't very helpful for people with sever depression, though the improvement is clinically signifigant.
Further, the study didn't have much data for the less severly depressed groups (I belive only three studies) and so they had to largely extrapolate from a pretty widely distributed dataset for the more severely depressed people.
I don't know what to make of it, really.
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MushmanTheManic
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: johnm214]
#8069865 - 02/25/08 07:48 PM (15 years, 11 months ago) |
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Quote:
it says many prescribed antidepressants aren't any more effective than SSRI's for people that are mildly depressed, and that they aren't very helpful for people with sever depression, though the improvement is clinically signifigant.
Umm... what? The article clearly is not about "many prescribed antidepressants" being more or less effective than SSRIs.
"Meta-analyses of antidepressant medications have reported only modest benefits over placebo treatment, and when unpublished trial data are included, the benefit falls below accepted criteria for clinical significance." (Emphasis added.)
Non-SSRI medications are not even mentioned in this article.
And the meta-analysis found that...
"...the difference between improvement in the drug groups and improvement in the placebo groups was 0.32, which falls below the 0.50 standardized mean difference criterion that NICE suggested."
Meaning there is NOT a statistically significant difference between the placebo and antidepressant groups.
Quote:
the study didn't have much data for the less severly depressed groups (I belive only three studies) and so they had to largely extrapolate from a pretty widely distributed dataset for the more severely depressed people.
Huh? It was a meta-analysis.
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MushmanTheManic
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: MushmanTheManic]
#8069873 - 02/25/08 07:49 PM (15 years, 11 months ago) |
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Quote:
Prozac, the bestselling antidepressant taken by 40 million people worldwide, does not work and nor do similar drugs in the same class, according to a major review released today.
The study examined all available data on the drugs, including results from clinical trials that the manufacturers chose not to publish at the time. The trials compared the effect on patients taking the drugs with those given a placebo or sugar pill.
When all the data was pulled together, it appeared that patients had improved - but those on placebo improved just as much as those on the drugs.
The only exception is in the most severely depressed patients, according to the authors - Prof Irving Kirsch from the department of psychology at Hull University and colleagues in the US and Canada. But that is probably because the placebo stopped working so well, they say, rather than the drugs having worked better.
"Given these results, there seems little reason to prescribe antidepressant medication to any but the most severely depressed patients, unless alternative treatments have failed," says Kirsch. "This study raises serious issues that need to be addressed surrounding drug licensing and how drug trial data is reported."
The paper, published today in the journal PLoS (Public Library of Science) Medicine, is likely to have a significant impact on the prescribing of the drugs. The National Institute for Health and Clinical Excellence (Nice) already recommends that counselling should be tried before doctors prescribe antidepressants. Kirsch, who was one of the consultants for the guidelines, says the new analysis "would suggest that the prescription of antidepressant medications might be restricted even more".
The review breaks new ground because Kirsch and his colleagues have obtained for the first time what they believe is a full set of trial data for four antidepressants.
They requested the full data under freedom of information rules from the Food and Drug Administration, which licenses medicines in the US and requires all data when it makes a decision.
The pattern they saw from the trial results of fluoxetine (Prozac), paroxetine (Seroxat), venlafaxine (Effexor) and nefazodone (Serzone) was consistent. "Using complete data sets (including unpublished data) and a substantially larger data set of this type than has been previously reported, we find the overall effect of new-generation antidepressant medication is below recommended criteria for clinical significance," they write.
Two more frequently prescribed antidepressants were omitted from the study because scientists were unable to obtain all the data.
Concerns have been raised in recent years about the side-effects of this class of antidepressant. Evidence that they could prompt some young people to consider suicide led to a warning to doctors not to prescribe them for the under-18s - with the exception of Prozac, which was considered more effective than the rest.
In adults, however, the depression-beating benefits were thought to outweigh the risks. Since its launch in the US in 1988, some 40 million people have taken Prozac, earning tens of billions of dollars for the manufacturer, Eli Lilly. Although the patent lapsed in 2001, fluoxetine continues to make the company money - it is now the active ingredient in Sarafem, a pill sold by Lilly for premenstrual syndrome.
Eli Lilly was defiant last night. "Extensive scientific and medical experience has demonstrated that fluoxetine is an effective antidepressant," it said in a statement. "Since its discovery in 1972, fluoxetine has become one of the world's most-studied medicines. Lilly is proud of the difference fluoxetine has made to millions of people living with depression."
A spokesman for GlaxoSmithKline, which makes Seroxat, said the authors had failed to acknowledge the "very positive" benefits of the treatment and their conclusions were "at odds with what has been seen in actual clinical practice".
He added: "This analysis has only examined a small subset of the total data available while regulatory bodies around the world have conducted extensive reviews and evaluations of all the data available, and this one study should not be used to cause unnecessary alarm and concern for patients."
http://www.guardian.co.uk/society/2008/feb/26/mentalhealth.medicalresearch
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SneezingPenis
ACHOOOOOOOOO!!!!!111!

Registered: 01/15/05
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: MushmanTheManic]
#8071147 - 02/26/08 01:22 AM (15 years, 11 months ago) |
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Quote:
"This analysis has only examined a small subset of the total data available while regulatory bodies around the world have conducted extensive reviews and evaluations of all the data available, and this one study should not be used to cause unnecessary alarm and concern for patients."
yes, do not be alarmed that you are paying shitloads of money for your libido crushing pez.
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johnm214



Registered: 05/31/07
Posts: 17,582
Loc: Americas
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: SneezingPenis]
#8071344 - 02/26/08 03:39 AM (15 years, 10 months ago) |
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yeah replace "SSRI's" with "placebo", my goof (in the first block you quoted from me)
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Quote:
The dataset comprised 35 clinical trials (five of fluoxetine, six of venlafaxine, eight of nefazodone, and 16 of paroxetine) involving 5,133 patients, 3,292 of whom had been randomized to medication and 1,841 of whom had been randomized to placebo.
venlafaxin and nefazodone aren't really considered SSRI's, though they do have this property.
--
I'll check out the rest of what you say later.
I'm kinda curious as to the relevance of the seemingly arbitrary "clinical signifigance" threshold they say is used to measure antidepressants.
I wonder how this figure is derived?
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badchad
Mad Scientist

Registered: 03/02/05
Posts: 13,372
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: johnm214]
#8071506 - 02/26/08 07:15 AM (15 years, 10 months ago) |
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In any meta-analysis, its easy to cherry-pick the studies you want to include. In this instance, the authors used many of the initial FDA-approval studies. This isn't necessarily inappropriate, but it certainly can skew the results because initial studies are usually conservative by design.
The major flaw of this analysis is that it fails to take into account clinical trials performed after FDA approval of a drug. The authors then portray the entire state of antidepressant medications based on these intial studies.
This can be clearly seen with Fluoxetine. For this analysis, 4 studies of fluoxetine were chosen. If you search pubmed for clinical trials with fluoxetine (and limit to humans) you receive about 1300 references.
In sum, in the case of Fuoxetine, the authors used 4 early studies to summarize the other 1297.
The other issue is that of statistics. Since they are taking the mean of the entire study, they are collapsing data across thousands of patients into an n = 35.
The study also fails to take into account other outcome measures, and never tries to correct for things such as dose.
-------------------- ...the whole experience is (and is as) a profound piece of knowledge. It is an indellible experience; it is forever known. I have known myself in a way I doubt I would have ever occurred except as it did. Smith, P. Bull. Menninger Clinic (1959) 23:20-27; p. 27. ...most subjects find the experience valuable, some find it frightening, and many say that is it uniquely lovely. Osmond, H. Annals, NY Acad Science (1957) 66:418-434; p.436
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MushmanTheManic
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: badchad]
#8072574 - 02/26/08 01:34 PM (15 years, 10 months ago) |
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Quote:
If you search pubmed for clinical trials with fluoxetine (and limit to humans) you receive about 1300 references.
Most clinical trials only have about five to thirty subjects. Plus, finding studies with compatible methodology and a usable statistic can be extremely difficult in the behavioral sciences.
Sure, thirty-five studies is not a huge number, but it isn't small either. Considering the size of these studies, this meta-analysis has a considerable amount of power.
"The dataset comprised 35 clinical trials (five of fluoxetine, six of venlafaxine, eight of nefazodone, and 16 of paroxetine) involving 5,133 patients, 3,292 of whom had been randomized to medication and 1,841 of whom had been randomized to placebo."
Quote:
Since they are taking the mean of the entire study, they are collapsing data across thousands of patients into an n = 35.
Yeah? That is how you compute Cohen's d statistic, isn't it?
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badchad
Mad Scientist

Registered: 03/02/05
Posts: 13,372
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: MushmanTheManic]
#8072722 - 02/26/08 02:12 PM (15 years, 10 months ago) |
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Quote:
MushmanTheManic said: Finding studies with compatible methodology and a usable statistic can be extremely difficult in the behavioral sciences.
Exactly, which is why using a criteria of "Clinical trials submitted to the FDA" isn't exactly a great criteria for inclusion in a meta-analysis. There is a lot more involved in designing a clinical trial than simply comparing it to placebo.
Adding to this is the difficulty of comparing 4 different compounds with differing pharmacology and you open up a host of problems.
-------------------- ...the whole experience is (and is as) a profound piece of knowledge. It is an indellible experience; it is forever known. I have known myself in a way I doubt I would have ever occurred except as it did. Smith, P. Bull. Menninger Clinic (1959) 23:20-27; p. 27. ...most subjects find the experience valuable, some find it frightening, and many say that is it uniquely lovely. Osmond, H. Annals, NY Acad Science (1957) 66:418-434; p.436
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MushmanTheManic
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: badchad]
#8072757 - 02/26/08 02:21 PM (15 years, 10 months ago) |
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Hmm... I can see what you're saying.
I think I might send a letter to Dr. Kirsch to ask him more about this study. His study was published by PLOS, which is a journal I trust, and an earlier study of his - extremely similar to this one - was published by the APA. So, I assume, since both of these studies have been published by reputable journals, that this meta-analysis isn't bunk, but I'd like to know why he chose clinical trials submitted to the FDA rather than other clinical trials.
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SneezingPenis
ACHOOOOOOOOO!!!!!111!

Registered: 01/15/05
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: MushmanTheManic]
#8073459 - 02/26/08 05:02 PM (15 years, 10 months ago) |
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the study isnt really saying that antidepressants are completely useless (but I will)... but it states many times that its goal was to find if there was a curved discrepency between the severity of peoples depression in regards to placebo/drug.
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appleorange
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Re: Recent Study by Kirsch, et al. - SSRI's no more effective than placebo [Re: SneezingPenis]
#8073664 - 02/26/08 05:49 PM (15 years, 10 months ago) |
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I don't doubt the placebo effect, but speaking personally from being on two different SSRI's I have a hard time saying they don't work.
Sure, they will numb you, kill your libido, but they are pretty effective in stomping out depression.
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