Researchers are developing blood tests to diagnose depression, removing the subjectivity and stigma of a depression diagnosis.
Image: flickr/r.f.m II
-
The Wisdom of Psychopaths
In this engrossing journey into the lives of psychopaths and their infamously crafty behaviors, the renowned psychologist Kevin Dutton reveals that there is a...
Read More »
Can a psychiatric disorder be diagnosed with a blood test? That may be the future if two recent studies pan out. Researchers are figuring out how to differentiate the blood of a depressed person from that of someone without depression.
In the latest study, published today (April 17) in the journal Translational Psychiatry, researchers identified 11 new markers, or chemicals in the blood, for early-onset depression. These markers were found in different levels in teens with depression compared with their levels in teens who didn't have the condition.
Currently, depression is diagnosed by a subjective test, dependent upon a person's own explanation of their symptoms, and a psychiatrist's interpretation of them. These blood tests aren't meant to replace a psychiatrist, but could make the diagnosis process easier.
If a worried parent could have a family physician run a blood test, it might ease the diagnosis process during the already tough time of adolescence, said Eva Redei, a professor at Northwestern University in Evanston, Ill., who was involved in the study of the teen-depression blood test.
If they hold up to further testing, blood tests could help young adults, who often go untreated because they aren't aware of their disease, get treated. The biological basis of a blood test could also help to reduce that stigma, researchers suggest. [10 Facts About the Teen Brain]
Depressing diagnosis
In the new study, Redei and her colleagues focused on early-onset depression, which occurs in teens and young adults before age 25. About 15 percent of young women and 7 percent of young men between ages 13 and 18 are estimated to have the disease.
This disease is a distinct condition, different from adult-onset depression, she said. In teens, "it has a somewhat greater genetic contribution, and also it has usually a harder course," Redei told LiveScience.
The researchers first looked at the genes of rats that had been bred to be either more or less depressed, considered the "genetic model." Next, they looked at four different strains of rats placed under chronic stress, an environmental factor that causes depression. They compared the gene-expression changes, which can occur as a result of stress, between the chronically stressed rats and individuals without extra stress.
The researchers then took 26 gene-expression changes they'd identified in the animals to see if they held up in depressed humans; they tested 14 depressed and 14 non-depressed teens. Eleven of the genetic markers faithfully distinguished between teens with and without depression.
Building to a blood test
In an earlier study, published in the Feb. 28 issue of the journal Molecular Psychiatry, researchers focused on a blood test for adult-onset depression. The researchers used nine markers, consisting of proteins and other body chemicals that had previously been identified as related to depression and brain functioning.
With these markers, they came up with a formula to give each patient's blood test a score, which indicated the likelihood of having depression.
The researchers analyzed the blood of 70 depressed adults and 43 non-depressed controls. The average score of the depressed patients was 85, and the score of the non-depressed patients was 33. The researchers said the test could detect depression in 90 percent of people who actually have the condition.
See what we're tweeting about
11 Comments
Add CommentFascinating article. And an optimistic finding, despite the small sample size. One problem with the reporting is the conflation of "genetic" with "blood markers" or "biomarkers." Authors were measuring gene expression levels, based on transcribed RNA, not actual DNA markers. It's not a HUGE problem, but it could affect the take-home message; biomarkers, gene expression levels and protein levels measured in blood are products of both genetics and environment, epigenetics, transcription factors, etc., whereas the "genetic code" is what you're literally born with--what's encoded in your DNA, and for the most part, unalterable. If we're talking about implications for stigma, it's an important distinction to make. You are not "born" with the DNA markers they are measuring. And so it also has implications for the importance of the interaction between genes and environment (early life stress, trauma, intrauterine effects, etc.) in the development of depression in these individuals.
Reply | Report Abuse | Link to thisIt is pretty funny to imagine this is some objective measure of anything.
Reply | Report Abuse | Link to this"Depression" is a wholly subjective diagnosis rendered by a pseudo-profession more interested in compensation for their doubtful services than anything.
They desire the obvious financial compensation ..as well as the less recognized but well known forms of compensation of social status and influence.
These forms of non-financial forms of compensation... blenderized with political motives into a reeking smoothie of self-interest... very often are a great deal more important than finances once basic food and housing needs are met.
No.. we see people who are awash in pseudoscience and who do not even possess insight into their own minds.. much less the minds of others..."diagnosing depression".
They are just diverting their own and everyone else's attention from their own deficiencies of being silly twits who cannot sort out what they want to see from what is really before their eyes.
These kind of efforts are the worst form of manipulations.
Imagine how low and stupid you have to be to claim it is somehow less demeaning for a person to be told.. you are a genetic defective.. a lower form of life than those who are going to seek compensation using you as the means to do so.... than for them to be told... you need to eat better and sort out your own mind if you want to escape these unpleasant feelings.
Too bad chemical treatments for depression aren't safer and more effective. Otherwise an alternative approach might be to simply treat all teens with antidepressants, much like livestock is routinely treated with antibiotics as food supplements... McXanex poppers, perhaps?
Reply | Report Abuse | Link to this"Eleven of the genetic markers faithfully distinguished between teens with and without depression."
Reply | Report Abuse | Link to thisFaithfully? the test actually compared teens with depression and teens not suffering from *any* DSM disorders.
Jennifer, I have to object to your use of the word "stigma" associated with depression. So many great people throughout the world suffer from this debilitating condition, disease, whatever you want to call it but labeling it "stigma" goes back to the dark ages. Our late friend Mike Wallace, Winston Churchill, and so many other great individuals suffered from this difficult condition but, without it, we might well be Nazi. Read a bit of history about those suffering an possibly be positive instead of stigmatizing.
Reply | Report Abuse | Link to thisI don't understand how "genetic markers are elevated"...Your genes are not fluctuating in levels like metabolites do. Your blood glucose level may be elevated, but your genes cannot be "elevated".
Reply | Report Abuse | Link to this1) Far from diagnostic test and I see no reason to claim it would lower stigma any more than it could raise stigma
Reply | Report Abuse | Link to this2) Fishing for correlates is good. As is:
Experimental group: subject with MDD or MDD and other DSM
Other group (not a control group): subject without any DSM
Results do not seem solid, especially at this level of enquiry (I only read once and am not well versed in stats)
3) Next step compare subjects with only MDD with subjects without MDD or with subjects with other DSM than MDD
If these results are duplicated in a much larger study and in studies by other groups of researchers, then I think this could be very useful. My main hope is that instead of detecting and treating the depression and stopping there, they use these markers to trace back to actual causes. Find the causes of these elevated markers and you may be able to prevent much of the depression from ever happening.
Reply | Report Abuse | Link to thisI'm also interested in the impact on the growing body of evidence that burn out and depression have the same symptoms but affect different areas of the brain.
"If these results are duplicated in a much larger study and in studies by other groups of researchers, then I think this could be very useful."
Reply | Report Abuse | Link to thisYes it could be very useful. But the study did not attempt to differentiate between subjects diagnosed with MDD (Major depressive disorder) and subjects with other mental disorders, so at this point I'm not sure scaling up the study is useful.
How do you breed rats to be depressed? "The researchers first looked at the genes of rats that had been bred to be either more or less depressed, considered the "genetic model."
Reply | Report Abuse | Link to thisIf that was possible then doesn't it assume that we know what genes cause depression? This study seems suspect.
The full paper is at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3337072/
Reply | Report Abuse | Link to thisHaving personally used st jogns wort to noticeable benefit, I think a quick medical advisement that said "a gene test suggests you could be much happier, we suggest any of these items (list of possible medications) at the complimentary pharmaceutical vending machine." would be of great benefit.
genetic testing makes bringing relief much easier as well as cheaper as there is less intermediation.