Researchers testing the blood of 14 teenage subjects with major depressive disorder and 14 with no disorder for a set of candidate biomarkers from animal models of depression found that 11 of the 26 candidate markers differentiated depressed participants from controls. Results will appear in Translational Psychiatry.
Note from Kermit Cole, “In the News” editor:
I have wrestled with including this item since it appeared a few days ago. The large flurry of news coverage, based on a small sample testing a rather broad assay of candidate markers, left me reluctant to present it as “news.” Such announcements are often trumpeted as the next big thing, with little notice that the results don’t pan out, while significant studies that question the basis for the standard of care garner little effective attention.
But the fact that a small, imprecise study can generate such a flurry of news could, as the “Daily Beast” points out, lead to large consequences, makes it important to include here.
“When something like this comes out and gets a lot of attention, it’s a false promise to parents, because it’s nowhere ready for prime time,” said Dr. Lloyd Sederer, medical director of the NY State Office of Mental Health in the Huffington Post. “Some of the risks have not been considered yet. And does it really shape, in any way, how effective your treatment is going to be now?”
I look forward to the responses of others in comments and blogs that I hope will come.
Los Angeles Times
Mad in America hosts blogs by a diverse group of writers. These posts are designed to serve as a public forum for a discussion—broadly speaking—of psychiatry and its treatments. The opinions expressed are the writers’ own.
One of the authors of this paper has a blog post: The ethics of a blood test for depression at http://notunlikeresearch.typepad.com/something-not-unlike-rese/2012/04/the-ethics-of-a-blood-test-for-depression.html
I don’t think most people need a blood test for depression. If they don’t feel depressed, then why treat them? And if they do feel depressed, then we still don’t know the best thing to do. I suppose it might be useful in differential diagnosis, if it could differentiate between clinical depression and physical conditions such as metabolic problems, vitamin deficiencies or the onset of dementia. But this study was with teenagers, probably healthy, too.
My take on fundamental flaws:
– Extrapolating an analog of human depression from rat behavior. Unknown what cognitive deficiencies or unpleasant physical sensations have been induced in rat.
– Given this, what the study has found is “marker” similarities between a (very small) human sample and unknown characteristics of specially bred rats.
– Very tiny study samples, easily influenced by researcher bias.
– Excessively optimistic projections of value of findings. False positive rates unknown.
If this were taken seriously by psychiatry, which it will be because psychiatry is an unusually gullible profession given to fads, it will be used as an argument to medicate children even if the blood test is not actually available.
Why? Because, simplistically, doctors (who should know better) will take this as evidence “depression” (however they define it) is biological and needs biological intervention, i.e. medication.
N =14 will tell you nothing at all. Thinking fast thinking slow has a chapter
dedicated to the dangers of inferring anything when sample size is tiny. How this stuff gets through an editorial board of a science beats me. K
This was exactly the conversation I had with Bob about posting. I was initially averse, but it’s interesting that something with no actual statistical significance can get so much press coverage, when things with real significance that challenge the status quo can find none.
Not that this study doesn’t tell us something, but the things we can learn from it don’t have much to do with what generally gets picked up on.
It’s interesting to think of the causes and consequences of a study like this. What are the interests of the researchers? What funding do they have, or might they hope to get?
Or, less nefariously, what are the assumptions and where do they lead? Would this provide a test that insurance will require to fund antidepressants? It’s all interesting to think about.
After some of the exchanges of the last few days I am more hopeful than ever that MIA can become a forum wherein professionals (psychiatrists included) might find the dialogue and information that may change the status quo. I have had feedback that encourages me that some of the research and conversations have been helpful in this regard.
I am reading Thinking fast Thinking slow at the moment and think it should be compulsory reading for all pyschiatrists, politicians etc. I think it sort of answers why this sort of week article gets published, because by being published they somehow make it available that there is blodd test and by being available we all get primed and then this is furthered by the press talking up the story and hey presto our lazy brains start thinking it is true without checking the facts first. It sort of works like advertising I think. The fact that it gets so much press coverage is probably because there is this all false hope that one day someone will crack this holy grail of medicine and we’ll get happy after that. P.s. I am a psychiatrist and love MAI for the wealth of information it contains.
Another ridiculous “study”. But the category of “depression”, and assuming it’s an illness, is problematic in the first place.
A small sample size can actually mean a dramatic impact. It is actually very hard to find statistically significant values if the sample size is low, even if there is actually a difference between control and experimental group. For example, genetic variants that lead to subtle changes in metabolism that lead to human disease often need very large sample pools to find statistical differences(by creating a tighter standard error of the mean).
Only very large differences can actually be suggested to be statistically distinct with a small sample size.
The fact that this tiny “study,” having no scientific significance for several reasons cited in earlier responses, received massive media coverage does not suprise me at all. Media coverage is the result of public relations campaigns, marketing campaigns, and pressure from powerful interests. Dr. Peter Breggin and I have observed and analyzed that potent mix for decades. The acceptance, ascendance and complete authority of biological psychiatric theory is the best PR and marketing campaign ever executed. After the incredible marketing coup of Prozac, followed by the ‘Decade of the Brain’ it is inevitable that other companies will attempt similar campaigns to move their product.
Finally, “biomarkers for depression” fits within the now culturally accepted paradigm that humans are their biology, and their feelings are biology, too. For discussion and details see psychiatrist Peter Breggin’s books Brain Disabling Treatments in Psychiatry, Talking Back to Prozac (2008), and Toxic Psychiatry among others.